Test 2 Flashcards

Question

Important cause of irrevesible divergence bw 2 separate species is

Answer 1

Natural selec - 2 closely related species may look almost identical but not be able to reproduce w each other

Answer 2

FALSE. Could be quick, like with galapagos finches, could be slow.

Answer 3

FALSE. Could very well happen, as seen in fossil record, and usually end up being recognized as new species.

Answer 4

TRUE. Still rapid change though as intense selection produces profound changes in trait in 100 generations or less

Answer 5

- criterion of interbreeding is meaningless - for classification, biologists use arbitrary measures of similarity based on characters of practical importance (e.g. composition of bacteria cell walls) OR increasingly on DNA sequence difs - sufficiently similar individuals that cluster together based on related characters are classed as same species - thus, NOT based on interbreeding patterns as in sexual reproduction

Answer 6

DNA sequences

Answer 7

Due to insertions and deletions (however rare in genes that code for proteins as they have major effect on sequence of amino acids in protein and make it non-functional). MOST CHANGES due to changes to individual letters of sequence.

Answer 8

Quantify their level of divergency precisely, which is difficult to do with morphological similarities and difs.

Answer 9

Which of the differences alter the protein sequence corresponding to gene in question (replacement changes) and which do not (silent changes). The more difs at sequence level, the more distantly related organisms are.

Answer 10

The theory of evolution

Answer 11

Silent, bc often have little or no effect on biological functions while replacement changes actually affect functioning of org. Most changes to AA sequence of protein impoair its function to some extent, so never contribute to evol difs in gene sequences that accumulate bw species as natural selection quikcly eliminates them

Answer 12

Through random changes in frequencies of alternative variants (gen drift) in finite pops. Since effect of gene is NEUTRAL, genes of next gen will be drawn randomly from parental pop. Frequency of mutant gene in progeny pop will not be same as its frequency in parents pop due to random factors (some producing more offspring while others none, and it being very unlikely for all individuals to produce exactly same number of offspring). Over gens, there will thus be continual random fluctuations in composition of pop, until eventually the silent gene is present in all (FIXATION) or disappears entirely from pop. In small pop, gen drift is fast so it wont take long for all members of pop to become the same. Process takes much longer in larger pop. Input of new neutral variants by mutation and changes in variant frequencies by drift determine variability in the pop.

Answer 13

Examination of DNA sequences of same gene from dif individuals from pop reveal variability at silent sites.

Answer 14

spread throughout whole pop and replacing alternative variants (although has much greater chance of being lost). Gen drift thus leads to evol divergence bw isolated pops, even without any selection promoting changes.

Answer 15

False. It is very slow, the rate of which depends on rate at which new neutral mutations arise, as well as rate at which gen drift leads to replacement of one version of a gene by a new one.

Answer 16

Only on the rate of mutation per DNA letter (the frequency with which a particular letter in a parent is mutant in the copy that is passed to an offspring). EXPLANATION: if no selec is acting, nothing affects number of mutational difs bw a pair of species except rate at which mutations appear in sequence and amount of time since the species' last common ancestor.

Answer 17

FALSE. Large pop has more bc there are more individuals in which a mutations might happen.

Answer 18

of mutations per gen vs rate of gen drift.

Answer 19

Molecular clock principle. Changes in genes are likely to take place in much more clock-like fashion than changes in traits subject to selection. Not very precise - its rates can change over time within the same lineage and bw lineages. Use of mol. clock allows biologists to roughly date divergence bw species for which there is no fossil evidence.

Answer 20

Environmental change. Variable rates and reversals of direction can occur.

Answer 21

One needs sequences from closest available species whose divergence dates are known. This method has been used to date timing of split bw lineage giving rise to modern humans and one leading to chimpanzees and gorillas for which no independent fossil evidence is available. Dates of 6 ot 7 million yrs have been estimated with considerable confidence.

Answer 22

That the rate of neutral sequence evolution depends on mutation rate and the is thus clock is exceedingly slow, since the rate at which single letters in the DNA change by mutation is very low

Answer 23

Amino acid sequence of proteins. Protein sequences evolve slower than silent DNA difs and are therefore useful for the task of comparing species that diverged a long time ago. It is impossible to count exactly the number of DNA mutations between such species, so scientists interested in reconstructing the times of divergence bw major groups of living forms use data from slowly evolving molecules. Dates are rough but estimates from many dif genes can improve accuracy.

Answer 24

- basic features of living cells - origin of human consciousness

Answer 25

modified (adapted) versions of pre-existing structures

Answer 26

Succession of small changes to a structure that already works but can be improved.

Answer 27

Proteins. They probs started as short chains of a few amino acids that could cause reactions to go a bit faster, and were successively improved as they evolved.

Answer 28

catalysing reactions better than when no protein is present, and then got successively better over evolutionary time. With this, there is no need to worry about the many millions of potentional non-functional sequences that will never exist.

Answer 29

Part of protein that is essential for its chemical activity is often only a very small part of its sequence - typical enzyme has just a handful of AA's that physically interact w the chemical that is to be changed by the enzyme - the rest of the protein mostly provides a scaffold that supports the structure of the part involved in the interaction. THUS functioning of protein depends critically on only relatively small set of AA's so new function could evolve by a small number of changed to the sequence of protein.

Answer 30

Many useful chemicals were probs present in the envi of early orgs. As life evolved, these became scarce. An organism that could change a similar chemical into the useful one would benefit and so an enzyme could evolve to catalyze that change. The useful chemical would now be synthesized from the related one. THUS a short biosynthetic pathways, with a precursor and product, would be favoured. Like so, pathways could evolve - backwards from their end-products - to build up the chemicals organisms need.

Answer 31

One might thinkt hat, even if the end products are useful, it would be impossible to evolve such pathways since evolution has no foresight and cannot build up a chain of enzyme reactions until its function is complete.

Answer 32

We need evidence for intermediate stages in the evolution of such characters, so: - fossil record - present-day species that show intermediate stages bw simple and more advanced stages (only source of info on features that do not fossilize)

Answer 33

Cambrian. With sudden change, there is virtually no fossil evidence concerning their ancestors so no proof of intermediate forms in evolution for these (does NOT mean that intermediates did not exist). DNA sequences are studied to see similarities, but we have no info on what they looked like, probs bc they were soft-bodied and thus unlikely to fossilize.

Answer 34

Flight - mistaking limbs for wings as wings adapted from limbs in bats - flying squirrels having same bones just extra flaps of skin for the wings

Answer 35

A retina is not useless w/out a lens. Many types of invertebrate animals have simple eyes, with no lens. Such animals do not need to see clearly - it is enough to perceive light and dark in order to detect predators. Starting with a simple ability of cells to detect light through rhodopsin protein, a series of steps followed, in which increased light-capturing abilities evolve step by step, leading eventually to focusable lens that produces a sharp image.

Answer 36

By means of receptors composed of a cluster of molecules of the light-sensitive protein rhodopsin (it is used in all animal eyes, and is also found in bacteria).

Answer 37

Adaptation is never perfect. Ageing is partly an unavoidable consequence of cumulative damage to the systems necessary for continued survival, and selection likely cannot prevent this.

Answer 38

Some organisms live longer than others (e.g. mice vs humans) and are able to replenish the traits that become diminished with age - e.g. reptiles teeth will renew from time to time, while a mammal will eventually starve to death bc is unable to eat w teeth that have worn out. Single-celled orgs like bacteria reproduce simply by dividing into daughter cells and the lineages of cells produced by the divisions have persisted over billions of years - they continually break down damaged components and replace them with new ones, they can continue to propagate indefinitely, given that harmful mutations are removed by selection.

Answer 39

Selection favours survival and reproduction early rather than late in life simple bc, on average, more individuals will be alive to experience the good effects. The greater the mortality due to accidents, diseases and predation, the more strongly will selection favour improvements early in life, relative to later on, bc few individuals can survive to late ages if the death rate from these external causes is high. Thus, mutations with harmful effects will be most strongly selected against if htey express their effects early in life.

Answer 40

That ageing evolves bc of the greater selective value of variants w favourable effects on survival/fertility early in life, compared with variants that act late.

Answer 41

- keep early-acting mutations rare in populations, while allowing ones with effects late in life to become common (many common human genetic diseases are due to mutations whose harmful effects appear only LATE in life, e.g. Alzheimer's) - variants that have beneficial effects early in life will be more likely to spread through the population than those whose good effects come only in old age. Improvements to early stages of life can evolve, even if these benefits come at the expense of harmful side-effects later on (e.g. higher levels of some reproductive hormones may enhance women's fetility early inl life, but at the risk of later breast and ovarian cancer, confirmed by experiments, OR fly experiment w breeding of a pop only with old individuals, offspring age slower but have reduced reproductive success early in life)

Answer 42

Species with low externally caused death rates should evolve low rates of ageing and longer life spans, compared with species with higher external death rates.

Answer 43

Strong relationship. Smaller species tend to age much faster than larger ones and reproduce earlier. This probably reflects the greater vulnerability of many small snimals to accidents and predation.

Answer 44

The difs often make sense in terms of differing risks of predation. E.g. many flying creatures are notable for longevity, which makes sense bc flying is a good defence against many predators.

Answer 45

Our closest relatives rarely live beyond 50 yrs and start reproducing earlier in life. Humans have thus probably substantially reduced their rate of ageing since diverging from our common ancestor w apes and postponed reproductive maturity. These changes are probs due to increased intelligence and ability to cooperate which reduced vulnerability to external causes of death and reduced the advantage of reproducing early.

Answer 46

It has led to a dramatic decline in mortality rates among adults, changing the relative advantages of early vs late reproduction by altering the natural selec affecting the ageing process in human pop's.

Answer 47

Large, slow breeding species (like mammoths) have been more severely affected than small, fast breeding ones, like mice.

Answer 48

Human activies causing loss of/damage to natural environments are causing the loss of species such as elephants and rhinos.

Answer 49

Consider Huntington's disease, caused by rare mutant gene. It affects ppl in their 30s or later. In a pop w high mortality bc of disease and malnutrition, few individuals survive to their 40s and carriers of disease have on average only slightly fewer offspring than unaffected individuals. In industrializes societies, with low mortality, ppl often have children later in life, in age when disease could appear, so affected ppl have fewer children, on average, than unaffected individuals. If current conditions continue, selection will gradually reduce the frequencies of mutant genes w effects expressed late in reproductive life, and survival rates of older individuals will increase.

Answer 50

- In social wasps, bees and ants, some of the females in a nest are workers who do not reproduce. They represent a small minority within the colony (often just single queen). Worker females look after queens' offspring and maintain and provide for nest. - In termites (other main group of social insects) both males and females can behave as workers. - In advanced social insects, there are often several dif castes which perform dif roles and are distinguished by difs in behaviour, size and body structure

Answer 51

sterile (e.g. naked mole rat - may be several dozen inhabitants of next and only single reproductive female. if she dies, there is a struggle to replace her among the other females but one wins). Many dif species have system of social castes - from insects to rats.

Answer 52

Members of a social group are generally close relatives, often share same mother and father. A genetic variant that causes its carriers to forgo their reproductive success to help raise its relatives may help the relatives' genes pass to next gen, and the genes are often the same as the helper individual's own genes bc of the relatedness (same mother or father means half of same genes is present). If sacrifice by sterile individuals results in sufficient increase in numbers of surviving and reproductively successful relatives, the increase in # of copies of the worker gene can outweigh the decrease due to their own lost reproductive success. The increase needed to outweigh the loss is smaller the closer the degree of relationship.

Answer 53

- Environmental cues, such as the amount/quality of food provided to the individual while a larva. - Ability to respond to the cues is genetically determined. A certain genetic variant might confer the potentiality of a sterile member of an ant colony to develop as a soldier (e.g.) so bigger jaws, and not a worker. Depending on whether soldiers make the colony better fit in the envi/pop (i.e. colony is better defended against enemies and better reproductivity on average), the success of this variant will increase in the colony. If the reproductively active members of the colony are close relatives of the workers, the genetic variant that induces some workers to become soldiers will be transmitted by the colony thru queens and males founding new colonies. THUS, selection can act to increase the representation of the variant among colonies in the species.

Answer 54

The cells produced from the egg and sperm fusion remain associated and most lose their ability to become sex cells and thus to contribute to the next gen. Since the involved cells are genetically identical, this would be advantageous if survival and reproduction were sufficiently increased in the group of associated cells, compared to single celled alternative. The non reproducing cells sacrifice their own reproduction for the benefit of the community of cells.

Answer 55

- We cannot use comparisons among living species to make firm inferences ab how they might have occurred. - Lack of any fossil record for early history of life or for human behaviour means we have no direct info about the sequences of events involved. - Guesses cannot be prevented, but they cannot be tested like the other evolutionary ideas.

Answer 56

- aim of current research is to find conditions resembling those of the early history of the earth, which allow the purely chemical assembly of molecules that can then replicate themselves. Once such self-replicating molecules have been formed, its easy to imagine how competition bw dif types of molecules could result in the evol of more accurate and faster replicating molecules (i.e. NATURAL SELECTION acting to improve them) - chemists have shown that the basic chemical building blocks of life (sugars, fats, AA's, constituents of DNA and RNA) can be formed by subjecting solutions of simpler molecules (of the type that are likely to have been present in the oceans of the early earth) to electric sparks and UV irradiation. There is limited progress in showing how these can be assembled into more complex molecules that resemble RNA and DNA and esp in getting such molecules to self replicate - once the above goal is achieved, the question of how to evolve a primitive genetic code that allows a short RNA or DNA sequence to determine a simple protein sequence must be solved - many ideas, no definitive solutions to problem yet

Answer 57

- difficult to state the nature of the problem clearly bc consciousness is hard to define precisely. It is probs a matter of degree, not kind, so that in principle there is little difficulty in imagining a gradual intensification of self awareness and ability to communicate during the evol of our ancestors - We know nothing of the details of the selective forces driving the evolution of human mental and language abilities - Biologists are making rapid progress in understanding the functioning of the brain. There is little doubt that all forms of mental activity are explicable in terms of the activities of nerve cells in the brain. These activities must be subject to control by genes that specify the development and functioning of the brain. Like any other gene, these will be liable to mutation, leading to variation on which selection can act. This is not just a hypothesis - mutations have been found which lead to deficiencies in specific aspects of speech of their carriers, leading to identification of a gene involved in the control by the brain of this aspect.

Answer 58

Language ability. Note: it develops gradually, and is seen even in animals (e.g. teaching parrot to talk). Gap bw ourselves and higher animals is more apparent than real.

Answer 59

Two advances mean that the process of evol through selection acting on random mutations of the genetic material is now much more credible than it was at the beginning of the 20th century: 1. we have a much richer body of data demonstrating the action of natural selection at every level of biological organization, from protein molecules to complex behaviour patterns 2. we also now understand the mechanism of inheritance, which was a mystery to Darwin and Wallace

Answer 60

Natural selection

Answer 61

TRUE. This knowledge of heredity and our understanding that natural selection drives the evol of organisms' physical and havioural characteristics does NOT imply rigid genetic determination of all aspects of such characteristics. - The traits which are actually expressed often depend on the particular environment in which an organism finds itself. - In higher animals, learning plays major role in behaviour, but the range of behaviour that can be learned is limited by the animal's brain structure, which is in turn limited by the animal's genetic makeup. Applied across species - no dog will learn to talk or humans cant smell rabbit at a distance.

Answer 62

a long process of natural selection that started tens of millions of yrs ago, when our ancestors started living in social groups. This does NOT mean that all details of people's behaviour are genetically controlled, or that they represent characteristics that increase human fitness.

Answer 63

FALSE. There is nothing in the theory of evol by natural selec to suggest that progress in evol is inevitable, and of course bacteria are still one of the most abundant and successful forms of life.

Answer 64

- cave dwelling species that have lost their sight - parasites that lack the structures and functions needed for independent existence

Answer 65

TRUE. Increased complexity may often provide better functioning, as in the case of eyes, and will then be selected for. If fuction is no longer relevant to fitness, its not surprising that the structure concerned will degenerate.

Answer 66

TRUE. Increased complexity may often provide better functioning, as in the case of eyes, and will then be selected for. If fuction is no longer relevant to fitness, its not surprising that the structure concerned will degenerate.

Answer 67

- natural selection - genetic drift - mutation - migration

Answer 68

- phenotypic similarity - sympatric (fairly easy to identify within a region), but problems arise from gradual differences across regions (allopatric) - genetic similarity also used to identify and define species (phylogenetic species concept)

Answer 69

- taxonomic (or morphological): based primarily on distinct measurable differences - biological: based on inter-fertility among individuals - BUT, concepts vary among groups of organisms: No universal species concept

Answer 70

- focuses on the PROCESS - geographic isolation alone is NOT sufficient - isolation does NOT have to be absolute (question of what cutoff?) - must be possibly interbreeding IN THE WILD - doesnot apply well for bacteria, asexuals, highly self-fertlizing species or fossils

Answer 71

- often called geographic speciation due to involvement of geographical isolation - allopatric speciation much more common and easier to evolve

Answer 72

- allopatric: 2 separate species merge (bc closeness) - sympatric: part of one population gets into another and then speciation occurs

Answer 73

- pre-zygotic RI barriers: finding a compatible mate and mating, fertilization - post-zygotic RI barriers: development and growth of zygote (F1), adult survival and reproduction (F1) - growth, survival, reproduction of offspring (F2)

Answer 74

- geographical, ecological - temporal, behavioural (mate recognition) - mechanical (gentical structure compatibility) - cellular (sperm-egg compatibility)

Answer 75

- caused by combinations of genes with low fitness in the HYBRID - types: INTRINSIC (inviability, sterility, or abnormal development of hybrids), EXTRINSIC (ecological mismatch of hybrid phenotype to environment) - CANNOT be directly favoured by natural selection (rather arise as an indirect byproduct of evolution acting separately in dif populations)

Answer 76

- the mule (it is a sterile hybrid cross of MALE DONKEY and FEMALE HORSE) - hinny (sterile hybrid of MALE HORSE and FEMALE DONKEY)

Answer 77

- mullerian mimicry in Heliconius butterflies - poorly adapted hybrids - hybrids have aberrant colour patterns: higher predation risk and lower mating success

Answer 78

- local adaptation by dif populations CAN lead to reproductive isolation AND speciation (bc distinct evolutionary responses to dif selective pressures. Local adaptation NOT absolutely necessary, but ACCELERATUREs population divergence and evolution of reproductive isolation) - much current research aims to determine the BIOTIC and ABIOTIC agents of selection and the underlying "SPECIATION GENES"

Answer 79

- populations diverge GENETICALLY as a result of evolutionary forces (mutation, natural selec, gen drift): become RI, foten as an INCIDENTAL byproduct of evol change within pops - allows speciation to occur: pops continue evolving and adapting INDEPENDENTLY, driving MACROevol diversification

Answer 80

- evolution of ecological and phenotypic diversity within a RAPIDLY multiplying lineage as a result of speciation - originates from a SINGLE common ancestor - process results in an array of many species - species differ in traits allowing EXPLOITATION of a range of habitats and resources

Answer 81

- recent common ancestry from a SINGLE species - phenotype-environment CORRELATION - trait UTILITY - RAPID speciation

Answer 82

- ECOLOGICAL OPPORTUNITY (abundant resources, few competitors, often encountered on oceanic islands/their aquatic counterparts, like African rift lakes) - ORIGIN OF A KEY INNOVATION (e.g. toepad in Anoles, floral nectar spur in Columbines) - HIGH RATES OF SPECIATION CHARACTERIZE THE CLADE (test by comparing island to mainland clade, e.g. Darwin's finches 7 Hawaiian honeycreepers also radiated on mainland, whereas Galapagos mockingbirds have NOT radiated on islands/continents)

Answer 83

- exchange of GENES b/w species as a result of OCCASIONAL inter-species mating (sometimes can reverse speciation process to MERGE 2 groups into one) - varies across tree of life (common in plants and fish, RARE in mammals) - can result in COMPLEX patterns of variation (can be evolutionarily significant for speciation, especially by POLYPLOIDY)

Answer 84

- an organism, tissue, or cell w/ MORE than 2 COMPLETE sets of HOMOLOGOUS chromosomes

Answer 85

- ALLOPOLYPLOIDY (e.g. AA x A*A* create AA A*A*): arises from DUPLICATED karyotype following hybridization b/w species, MOST COMMON type of polyploidy - AUTOPOLYPLOIDY (e.g. AA into AA AA): arises from DUPLICATED karyotype within a species (e.g. non-disjunction)

Answer 86

- polyploids are REPRODUCTIVELY ISOLATED from their diploid parents (hence a form of SYMPATRIC speciation) - polyploids exhibit NOVEL PHENOTYPES (allows exploitation of NEW habitats) - polyploids often show GYBRID VIGOR due to heterozygosity, particularly in ALLOPOLYPLOIDS - Polyploid origin for approx 50% of flowing plants (many crops plants and invasive species)

Answer 87

FALSE. NOT unidirectional - i.e. species can merge and diversify throughout time.

Answer 88

- binomial nomenclature - hierarchical system of classification: (kingdoms, phyla, classes, orders, families, genera, species)

Answer 89

- name is a KEY to shared info on an organism - therefore has PREDICTIVE power - enables INTERPRETATION of ORIGINS and EVOLUTIONARY HISTORY

Answer 90

- a single names taxonomic unit at ANY level

Answer 91

- theory and practice of CLASSIFICATION and NAMING

Answer 92

- study of BIODIVERSITY and EVOLUTIONARY RELATIONSHIPS among organisms

Answer 93

- outgroup taxon: furthest taxa of tree - ingroup taxa: all inner taxa of tree (before the furthest one) - terminal nodes: taxa - terminal branches: accumulated evolutionary change - internal nodes: common ancestors, speciation - internal branches: accumulated evol change

Answer 94

- understand history of life - understand large scale patterns of evol - understand how many times traits evolved, how fast, under what conditions - PRACTICAL: where/when parasites spread, which flu strain was MOST successful last year, what the driver mutations are as SARS-COV-2 evolves

Answer 95

- Includes the COMPLETE SET of species derived from a common ancestor - a SINGLE ancestor gave rise to ALL species in that taxon and NO species in any OTHER taxon - much preferred because they link taxon names to evolutionary history

Answer 96

- Contains SOME, but not all species derived from a common ancestor - a taxon whose members are derived from TWO or more ancestral forms, NOT common to all members

Answer 97

TRUE. Descent with modification.

Answer 98

the identification and distinction of ANCESTRAL (trait SHARED with common ancestor) and DERIVED (trait that DIFFERS from ancestral trait in a lineage) traits.

Answer 99

- homology (similarity of traits due to SHARED ANCESTRY) - homoplasy (similarity of traits as a result of CONVERGENT EVOLUTION)

Answer 100

Human and fish skeleton

Answer 101

- the independent evol of structures that RESEMBLE one another and perform SIMILAR functional roles due to SHARED ECOLOGY of unrelated organisms

Answer 102

- convergent evol of succulence and spiny growth form in desert environments (cactus family vs. spurge family vs. milkweed family all developed similar traits/looks) - cichlid fishes of the African great lakes: independent evolutionary radiations in 2 lakes, similarity in form indicates convergence in FEEDING strategies

Answer 103

- all life is related through branching descent - common genetic code is EVIDENCE that all life IS related - evolutionary relationships among species are reflected in their DNA and proteins (learning about protein function in ONE species can tell us about its function in OTHERS, e.g. mice, rats, flies, worms vs. humans)

Answer 104

- genes or parts of a gene can be SEQUENCED for dif species - species can be ASSESSED for changes in sequence of nucleotides - changes can be used to INFER relationships in a phylogeny

Answer 105

- origin of a NOVEL trait resulting in ADAPTIVE RADIATION - carriers of the trait can EXPLOIT new resources or sets of habitats - usually associated w/rapid evolutionary diversification (e.g. adaptive radiation)

Answer 106

- key innovation could increase speciation OR decrease extinction to influence NET diversification - equation: diversification = speciation - extinction

Answer 107

- with one phylogenetic comparison, it is difficult to say a key trait IS involved - instead, REPLICATE comparisons of MULTIPLE groups adds more evidence

Answer 108

- COEVOLUTION b/w insects and plants likely drives HIGHER rates of speciation in herbivores

Answer 109

- species with more SEXUAL SELECTION - ANIMAL POLLINATION in plants - increased DISPERSAL - increased RANGE SIZE

Answer 110

ALL organisms have an inherent tendency to BECOME more complex

Answer 111

TRUE. Eukaryotes (plants, fungi, animals) and bacteria (great complexity) vs. archaea.

Answer 112

- greater complexity arises from greater 'cooperation' amongst PREVIOUSLY independent units - talks about origin of: cells, chromosomes, genetic code, sexual reproduction, eukaryotes, multicellularity, colonies (e.g. nonreproductive castes) - SMALL number of events led to major changes in how inheritance worked - previously independently evolving units MERGED, leading to higher-level complexity and specialization through DIVISION OF LABOUR

Answer 113

- most phenotypic traits we study in orgs arose due to selection that increases FITNESS of individuals (may OR may not be good for species - e.g. sexual selec for showy coloration may increase chance of extinction bc of higher predation. ALSO, individual selection is USUALLY stronger than group selection) - traits that are "good for species" but that REDUCE FITNESS of individual CANNOT be favoured by INDIVIDUAL SELECTION

Answer 114

- HIGH RELATEDNESS (genes that lead to helping relatives can spread via natural selec) - RECIPROCAL ALTRUISM (in cases where orgs repeatedly encounter each other, mutual cooperation can lead to HIGHEST fitness) - BUT, cooperation SOMETIMES breaks down (e.g. selection for 'cheaters')

Answer 115

- genes are the unit of inheritance, so ultimately target of selection is the GENE

Answer 116

- cheaters use common resources at expense of others - e.g. mitochondria that promote their own replication even if it comes at expense of overall fitness of organism - cheaters are not necessarily as efficient - cheaters ARE better at invading the next generation, they do this at expense of whole organism, and across many generations, so cheater DNA loses out to wildtype DNA at POPULATION LEVEL - ability to survive in stressful environments can foster tolerance to cheating, inadvertently prolonging persistence of cheater genotypes - could be useful in understanding diseases associated with disfunction of organelles (for e.g.)

Answer 117

- FALSE - genomes are composed of UNRELATED genes and alleles that have been inherited from dif places - segregation, recombination and random mating ensures that they are MOSTLY passed on independently - yet genes typically persist by improving fitness of the "group" as a whole

Answer 118

- many features of individual orgs prevent competition WITHIN an individual (prevents evol within individuals, align fitness interests) - ensures that many genes succeed by ENHANCING fitness of the organism

Answer 119

- MITOSIS AND MEIOSIS (ensures that alleles dont compete within an individual, FAIR REPRESENTATION of gene variants among daughter cells) - DEVELOPMENT AND MULTICELLULARITY (starting from a SINGLE CELL prevents initial competition among cell lineages) - UNIPARENTAL INHERITANCE OF ORGANELLES (chloroplasts and mitochondria replicate asexually, PREVENTS COMPETITION within cells of dif organelle genomes) - when CHEATING ALLELES spread, strong selection on rest of genome for SUPPRESSION of cheating

Answer 120

- by increasing individual fitness - positive natural selection on alleles

Answer 121

- meioitic drive - over replication

Answer 122

- if an allele can bias its own transmission (i.e. by enhancing its own transmission, 1 allele has higher probability to spread), then it can spread to higher frequency even while REDUCING individual fitness - "selfish" genetic element relative to organism's fitness interests

Answer 123

higher INDIVIDUAL fitness

Answer 124

- expected 'fair' meiosis does NOT occur bc majority of offspring possess allele combo that has enhanced transmission

Answer 125

- over replication creates self-replicating segments of DNA - transposable elements' replication separated from cellular replication - ensure their OWN over-representation in offspring (cheating of Mendel's laws) - transposable elements can make up greater than 50% of DNA in genomes of some species

Answer 126

- alleles arising elsewhere in genome that SILENCE transposable elements will be FAVOURED by individual selec (e.g. mechanisms controlling DNA and histone methylation) - transposition-selection balance

Answer 127

- piRNAs - RNA interference

Answer 128

rampant activation of transposable elements

Answer 129

a form of mutation that can disrupt a gene

Answer 130

- transposition increases transposable element abundance - natural selec against harmful effects on the org reduces abundance of chromosome copes with MOST transposable elements - overall abundance results from a balance b/w these opposing forces

Answer 131

- lack of mitosis and meiosis by plastids sets up potential for spread of SELFISH elements

Answer 132

- uniparental plastid inheritance strongly reduced competition WITHIN individuals - consistent w/ hypothesis that it evolved to MAINTAIN cooperation (e.g. active exclusion of sperm mitochondria at fertilization, that is, only egg mitochondria is passed down to offspring)

Answer 133

- MATERNAL inheritance of cytoplasmic genome vs. BIPARENTAL inheritance of nuclear genome - mitochondrial mutations that enhance MATERNAL fitness can spread, even if cost is severe to MALE fitness

Answer 134

- new mutations in mitochondria that make HERMAPHRODITIC plants "male sterile" can spread - "male sterile" hermaphrodites = "female" bc they favour mitochondrial transmission - can reduce fitness of plant as a whole - leads to evolution of nuclear 'restorer' alleles that re-enable fertility through pollen (ARMS RACE co-evolution of CMS (cytoplastic male sterility) and restorer genes) - mitochondrial mutations that make a HERMAPHRODITE plant into a "male sterile" female WILL spread, even if they REDUCE fitness of individuals - "male sterility" DECREASES fitness through pollen (might increase fitness through ovules bc re-allocation of resources to ovules, but NOT double that of the hermaphrodite)

Answer 135

- an individual animal/flower that has BOTH male and female reproductive organs

Answer 136

- starting from a SINGLE CELL reduces competition within individuals - separation of GERMLINE with limited numbers of cell divisions inhibits transmission of SELFISH cell lineages - tumor SUPPRESSORS, other features inhibit unregulated cell division - BUT somatic mutation is inevitable in long-lived multicellular organisms (some of those somatic mutations might be selectively FAVOURED WITHIN an individual)

Answer 137

- WITHIN an individual - spreads commonly in tissue that is relatively undifferentiated (evolved resistance to treatment/immune system) - illustrates the "short-sightedness" of evolutionary process

Answer 138

- many features ensure that variance in fitness WITHIN an individual is minimized - ensures that many genes succeed by enhancing the fitness of the organism ('group') - BUT countless ways to evade cooperation - presence of strong selection on rest of genome ('policing') seems essential to maintain higher-level cohesion

Answer 139

- alleles - organelles - tumors - individuals

Answer 140

- agricultural relevance (pesticide and herbicide resistance) - evolutionary medicine (evolution of resistance to antibiotics, evolution-proof vaccination) - global chance and evolution (adapt or go extinct)

Answer 141

- we use chemicals to combat pests and pathogens - we create strong selective pressure for resistance (fitness advantage to resistance genotypes arising from mutation and gene flow) - weedy plants have repeatedly evolved resistance to herbicides (SUPERWEEDS!!) - can we design "evolution-proof" solution??

Answer 142

- pre existing genetic variation in the pop - gene flow ('epidemic spread' of resistance from one region to next) - new mutations (in very large populations new, simple mutations may be introduced at a HIGH rate)

Answer 143

Depends on how resistance tends to EVOLVE

Answer 144

outcrossing, selfing.

Answer 145

- multi herbicide treatment (makes new adaptation LESS likely, requires more complex adaptation) - rotation of dif kinds of herbicides (weeds regularly hit by dif selection pressures) - BUT could select for GENERALIZED resistance

Answer 146

- insecticide in major prevention strategy - strong selective pressure on mosquitoes has led to rapid evolution of resistance

Answer 147

- tailor insecticide application to knowledge of mosquito generation times and spatial distributions - goal: minimize selection for mosquito resistance while still reducing malaria transmission

Answer 148

TRUE. - single mutations unlikely to confer resistance to MULTIPLE DRUGS with dif mechanisms of action - lower viral loads make multiple mutations less likely

Answer 149

FALSE. Mutations to many dif genes lead to drug-resistant tumors.

Answer 150

- strong, prolonged selec pressures using same chemotherapy drugs (may not be best solution bc selects for resistance) - cycling drugs, multidrug cocktails, lower doses of drugs (ethical considerations make tests of theory for human application challenging, but could a be better option)

Answer 151

- loss of habitat - habitat fragmentation - altered abiotic conditions (temperature, precipitation, pH, salinity, chemical pollutants) - altered biotic composition (transport of species, invasive species)

Answer 152

- permanent elimination of a species - normal evolutionary process (in undisturbed ecosystems, extinction rates have been estimated at 1 species lost every 10 yrs) - astoundingly increased rates of extinction during the past century (massive habitat destruction, particularly in tropical regions, at least 4-6k species per year)

Answer 153

- loss of genetic diversity - loss of heterozygosity - inbreeding depression - fixation of deleterious alleles - inability of populations to adapt

Answer 154

- strategies for reducing inbreeding depression in small pops, particularly captive animal species - founding individuals: speke's gazelle, siberian tiger, european bison, indian rhino

Answer 155

Depends on: - population size - beneficial mutation rate - how much fitness was reduced

Answer 156

- theory - studying patterns in nature - controlled experiments

Answer 157

- NOT environmentalism - NOT recycling and blah blah IT IS science of: - how organisms interact w/ each other and with their environment - distribution and abundance of species - structure and function of ecosystems - science of BIODIVERSITY

Answer 158

Between organisms and their environment

Answer 159

Life did not take over the globe by combat, but by networking. Lynn Margulis.

Answer 160

FALSE. IS NOT.

Answer 161

- lab mice - fruit fly (Drosophila melanogaster) - Arabidopsis thaliana (plant) - basically all other living things are NON-MODEL organisms

Answer 162

ALL the individuals of SAME species in ONE place at ONE time (all zebras in a savanna)

Answer 163

ALL species living together in one place at one time (all zebras, giraffes, elephants, plants, insects, etc. in a savanna)

Answer 164

ALL species plus the non-living environment (the entire savanna)

Answer 165

TRUE. (e.g. mountain lion almost everywhere, AMerican Pika almost nowhere)

Answer 166

Dispersal, into abiotic conditions (climate, nutrients), into species interactions (competition, predation, mutualism), into species in a community.

Answer 167

- dispersal - climatic or other inexhaustible conditions (e.g. temp, salinity, etc) - food or other exhaustible resources (e.g. nutrients, space, etc) - species interactions (e.g. competition, predation or mutualism) - these factors vary across space and time, we envision gradients of conditions - organisms perform best at certain portions of gradient

Answer 168

- reproduction - individual growth - individual survival

Answer 169

human activities

Answer 170

- Darwin reads Thomas Malthus’ “essay on the principle of population” - ideas of struggle for existence

Answer 171

- Spix's macaw - extinct in wild in 2019, decimated by pet trade and habitat loss - recent attempts to reintroduce birds bred in captivity back into wild

Answer 172

- combination of physiological tolerances and resource requirements of a species - in other words, a species' place in the world - what climate it prefers, what it eats, etc. - a concept w a long history in ecology

Answer 173

- niche is an n-dimensional hypervolume in which each axis is an ecological factor important to the species being considered - named after G. Evelyn Hutchinson

Answer 174

- temperature mostly a function of LATITUDE - rainfall mostly depends on ATMOSPHERIC CIRCULATION, offshore ocean currents, rain shadows - these factors determine BIOMES

Answer 175

- higher latitudes colder, seasonality a function of TEMPERATURE (summer-winter), light strikes earth at a lower angle, so greater area for incident sunlight - lower latitudes warmer, seasonality a function of RAINFALL (dry season-wet season), sun is closer to perpendicular and shines directly down on earth's surface, light hits at higher angle so smaller area - note the critical role of earth's tilt in producing seasons

Answer 176

- Hadley cells - heated air rises, air cools as it rises. As air cools, water vapour condenses and falls as rain near the equator. Air warms again as it falls. Creates dry, high pressure areas.

Answer 177

- as one goes through dry, triggers next to go through wet climate - Polar cell, Ferrell cell, 30 deg N, Hadley cell, STRONGEST DRIVER HERE, then same 3 cells in sourthern hemisphere

Answer 178

- shows line of rain clouds across Pacific - shifts seasonally, producing rainy and dry seasons in some parts of trips

Answer 179

- earth's rotation deflects winds - objects (including hurricanes) appear to be deflected EASTWARDS as they move away from equator and deflected WESTWARDS as they move towards equator

Answer 180

Coupled cells + Coriolis effect

Answer 181

- vegetation growth (primary productivity) increases with MOISTURE and TEMPERATURE - vegetation stature also INCREASES - so, regions with certain combinations of moisture and temperature develop predictable, characteristic types of vegetation = BIOMES - SEASONALITY is secondarily important

Answer 182

- tropical rainforest has has highest mean annual temp and highest mean annual precipitation (highest productivity) - desert has highest temp, lowest precip - very low productivity - lowest productivity in regions with lower precipitation (no matter the temp) - so desert, tundra are here - higher productivity entails high precipitation (tropical rainforest is highest)

Answer 183

Near 30 degrees N and S (above equator).

Answer 184

- Temperature: land changes temp more readily than water; so MARITIME climates are moderate, CONTINENTAL climates are extreme; oceans provide thermal inertia - Precipitation: evaporation high from warm bodies of water, low from cold; prevailing winds; OROGRAPHIC PRECIPITATION: air forced up mountainsides undergoes cooling, precipitates on upper windward slopes; RAIN SHADOWS created on leeward slopes of mountain ranges; seasonality of moisture also IMPORTANT

Answer 185

- distribution of landmasses - temperatures vary more in Northern hemisphere where moderating influence of water is less

Answer 186

- driest deserts occur inland of cold-water upwellings - cold water leads to dry air

Answer 187

- animals' geographical ranges often correspond to biomes (i.e. limited by climate or vegetation) - but sometimes not. Possibilities include: transcend biomes (ecological versatility, super generalists), not at limits bc of recent history (e.g. limited dispersal), limited by other organisms (enemies, friends)

Answer 188

- uses data from a species' present distribution to predict where a species can live - useful for modelling: biological invasions, how species' ranges may shift as climate changes, spread of vector-borne diseases, etc. - usually relies on climate data (more rarely on other niche axes, such as resources)

Answer 189

- predicted range shift: slight, staying in same general range - observed: moving polewards at greater than expected rate, increasing rate with each decade - although many factors influence a species' range, there is considerable evidence that numerous species are moving POLEWARDS to track recent changes in climate

Answer 190

- more than just the number of species at a site, also the DIVERSITY of their morphologies, physiologies and behaviours

Answer 191

- physiologists study how organisms acquire energy and nutrients and tolerate physical conditions - ecologists study how organisms deal with their environment and how the environment limits where they live - physiological ecology (ecophysiology) is simply the study of physiology in the context of an organism's ecology

Answer 192

- RANGES OF TOLERANCE ultimately limit distribution - organisms are complex chemical reactions - reactions occur (enzymes function) best at optimum temperatures and osmotic conditions, where fitness is maximized - many mechanisms for HOMEOSTASIS have evolved to challenge hostile environments - maintenance of homeostasis requires energy and is often limited by CONSTRAINTS AND TRADEOFFS

Answer 193

- an organism's physiology reflects climate and other conditions to which the org is adapted - dif environments lead to dif solutions (i.e. dif physiologies) - similar environments often lead to similar adaptations (even in dif taxa, i.e. convergent evolution) - e.g. animals that live in cold places tolerate colder temps than animals that live in warm places.

Answer 194

TRUE. Temperature animals ALSO tolerate a wider RANGE of temperatures than tropical animals.

Answer 195

- poikilotherms (most reptiles, amphibians, fish, invertebrates) lack PHYSIOLOGICAL means to deviate from environmental temperature (although they use BEHAVIOURAL means), their temperatures FLUCTUATE - homeotherms (birds, mammals) must regulate heat balance to keep internal temp within a narrow range, many traits contribute, heat balance is esp important to them

Answer 196

- poikilotherms have lower energy requirements than similarly sized homeotherms bc maintaining a constant internal temp required energy - homeotherms must thus consume more food for energy

Answer 197

- RADIATION (heat transfer by electromagnetic radiation) - CONDUCTION (transfer by direct contact with substrate, e.g. feet lose heat to ground) - CONVECTION (heat transfer mediated by moving fluid, usually air or water) - EVAPORATION (efficient cooling from wet surfaces) - REDISTRIBUTION (circulatory system redistributes heat among body parts, esp CORE (heart) to APPENDAGES (fingers))

Answer 198

- homeostasis and surface are to volume (SA:V) ratio - SA determined EQUILIBRATION RATE - volume provides ENERTIA - smaller radius, greater SA:V ratio so organism equilibrates QUICKLY (preferred by animals in hot areas) - greater radius, smaller SA:V ratio and org equilibrates MOST quickly (preferred by animals in cold environments bc less SA exposed so less heat lost to envi)

Answer 199

- homeotherms tend to be LARGER at higher latitudes (colder) - size MATTERS - e.g. tropical bear has short fur, polar bear has long fur

Answer 200

- even though they are big, tropical animals, they used to be MAMMOTHS (so elephants) in COLD places

Answer 201

- sometimes SA is needed for function - sometimes particular shapes are needed for function - tradeoffs and adaptive compromises

Answer 202

- Chrysopelea gliding snake, Borneo - long, flat, skinny snake - restricted to warm tropics - terrible shape IF snake lived in cold area bc too much SA exposed, lots of necessary heat lost

Answer 203

- American Pika, Ochotona princeps (alpine tundra rabbit) - restricted to cold habitats - spherical shape, reduced ears

Answer 204

- homeotherms tend to have smaller appendages at higher, colder latitudes - SHAPE matters - e.g. big ears facilitate heat loss to environment so such animals are usually found in tropical climates - arctic (small ears, kept close to body) vs. desert (long, big ears that stick up) hares

Answer 205

INSULATION - fur - blubber - feathers (dinos had feathers, but can't see them in fossils)

Answer 206

- sheep (thick insulation of fur, big energy investment bc very heavy) - seal (thick insulation of blubber, 58% of cross-sectional area) - birds (hair and feathers)

Answer 207

Hair and feathers. Birds are able to turn into spheres with feather adjustment to keep warm. Similar to human goosebumps.

Answer 208

- Vascularization. - E.g. veins and arteries in ears of rabbits of deserts - matters for heat balance - highly vascularized ears help to shed heat through blood in veins

Answer 209

- TRUE - arteries and veins should be appressed in appendages to conserve heat; separated in appendages designed to SHED heat - countercurrent flow maintains gradient, so heat is ALWAYS flowing from outgoing blood to incoming blood - heat transfer occurs in counter-current flow system (cold on tips, warm closer to center of body) - matters for heat balance - in COLDER climates, veins and arteries are more separated to avoid this cooling effect

Answer 210

- matters for heat balance - dogs pant, humans sweat

Answer 211

- important for heat balance - e.g. staying in shade, staying hydrated, less movement, spraying with water

Answer 212

- weasels are small predators, short-furred, very long and thin - in winter = ermine, active all year, camouflaged for snowy environment - curls into flat disk when cold, stays stretched out when warm - metabolism of cold stressed weasels is 50-100% greater than that of normally shaped mammals of same weight, can be attributed to their greater SA, shorter fur and inability to attain a spherical resting posture - in evolving elongate shape which enables them to enter confined spaces in search of prey, weasels have SACRIFICED energetic efficiency - increased ability to obtain prey, made possible by elongate shape and sexual dimorphism in body size, apparently more than COMPENSATES for energetic cost of being long and thin - so, weasel body plans are well-suited for WARM climates, but live in COLD (paradox!) - paradox involved requirements of weasel's predatory lifestyle: typical weasel prey are pocket gophers, which leave underground burrows - weasels also hunt voles in snow tunnels

Answer 213

TRUE. Energetic efficiency has played a significant role in evolution of body shape and size.

Answer 214

- TRADE OFF (like compromise) - being long and thin makes weasels subject to thermal stresses (COSTLY) but allows them to be better predators (BENEFICIAL) - bc they are long and thin, we infer that fitness GAINS of being a good hunter offset the fitness COSTS of an expensive metabolism - if they can get enough prey, they can stay warm DESPITE their heat-wasting shape - phenotypes of all orgs are riddled with compromises dictated by trade offs

Answer 215

- TRADE OFFS (being good at x may necessarily imply being bad at y) - CONSTRAINTS (selection builds on what is already there, esp existing developmental programs)

Answer 216

NO. Tinkering is possible, NOT fresh redesign.

Answer 217

- maintaining of constant internal conditions even with fluctuating external conditions - costs energy - is thus limited by trade offs

Answer 218

- heating/cooling animal enough that they lose a particular function (e.g. ability to walk)

Answer 219

TRUE. Equator has more constant temps than those at higher/lower latitudes.

Answer 220

TRUE. Shows proof for Bergmann's rule

Answer 221

For insulation and only LATER for flight

Answer 222

Geography and climate

Answer 223

- HUMANS are now moving species into new regions where some become serious pests - CLIMATIC WARMING is changing the distributions of many species, causing many ranges to expand toward the poles

Answer 224

FALSE. Not always clearly understood, many ecological processes may be involved.

Answer 225

At equator. There, more freshwater from rain is present so the people on the ship can drink the water, while they can't drink seawater.

Answer 226

More likely to get stuck at EQUATOR because the two opposing cells AROUND equator cancel each other out, preventing ships from having one wind to be influenced by.

Answer 227

- Bc of the tropical oceans forming a barrier that they have not been able to cross to enter the Arctic Ocean

Answer 228

- in study of distribution - movement is crucial in many ecological situations

Answer 229

ISOLATION, or, lack of dispersal - this explains why certain animals are found in only a certain place (e.g. kangaroos in Australia)

Answer 230

- zoos (e.g. penguins) - botanical gardens (relate to distribution of plant life)

Answer 231

- Alfred WALLACE - has been the basis of the analysis of geographical distributions of animals, plants, and microbes - provides a good starting point for understanding species ranges - a pattern written by the isolation of continents and regions by GEOGRAPHIC BARRIERS, leading to dif evolutionary paths and thus dif assemblages of species - the starting point for trying to understand why a particular species lives in a specific region and what the consequences might be of moving species ACROSS these boundaries

Answer 232

- North America (Nearctic) - Eurasia (Palearctic) - South America (Neotropical) - Africa (Ethiopian) - Australia - Indian Subcontinent (Oriental)

Answer 233

- continental drift over the last 200 mill years such as mountain ranges that affected evolutionary processes - first recognized by Alfred Wallace, then updated by Holt et al.

Answer 234

- TRANSPLANT EXPERIMENTS - move the organism to the new area (i.e. try it out) - if it survives there and reproduces, you have good evidence that former distribution was restricted by LACK OF DISPERSAL - in practise, many separate transplant experiments may be needed to define the limits of a species' potential geographic range

Answer 235

- most of the crops we grow are introduced species of plants, so experiment can benefit humans - many of our serious pests are also introduced species and the ecology of invasive species has a strong economic impact on our lives - many pest transplantations are accidental, but some of worst pest species introductions were deliberate - dramatic effects of successful transplants (e.g. starling) overshadow failures of other introductions

Answer 236

- elaborate series of inspection and quarantine procedures in dif nations

Answer 237

- president of American Acclimatization Society tried to introduce every bird species mentioned in the works of Shakespeare into North America, he released STARLING birds that then rapidly expanded range across North America (westward and northward), due to irregular migrations and wanderings of non-breeding juvenile birds. This bird is now one of the more common birds in N. America - cane toad. Native to central and south America from Mexico to Brazil. Was widely introduced in the 20s to islands in Caribbean, Pacific and Australia bc it was thought to control scarab beetles (insect pest of sugarcane). Toad is poisonous though, so humans and other animals eating the toad eggs die from the toxin. BC they're toxic, they've been able to move across northern Australia (and very rapidly) bc no predators eat them. The toad feeds on insects mainly, often those that do more good than harm, they were seen to NOT control insect pests of sugar cane. Breed very quickly. Breed in small ponds, so removing artificial water bodies would help to stop expansion of range of toad. ISSUE tho, most water bodies that would need to be drained are on pastoral lands so would have economic losses. Predicted effect of toad was massive mortality to predatory birds, reptiles and mammals, but actual impact is not as severe. Predator populations, e.g. lizards snakes and crocodiles, were severely reduced but recovered quickly (few decades). No native species have gone extinct, taxa are mostly unaffected (mostly bc of their physiological ability to tolerate toad toxins and reluctance of many native predators to consume the toads, either innately or learned response).

Answer 238

- we should NOT introduce species in the blief that they are beneficial without extensive studies - too many "desirable" introductions over last 2 centuries have turned out to be ecological disasters - detailed data on pops of predators and competitors and insects consumed is lacking - ideally, ecologists need before AND after data to evaluate the impact of ANY introduced species and little of this has been available for MOST pest species

Answer 239

- agricultural crops - fishes led to improved fishing (e.g. rainbow trout allowed for trout fishing to expand, but led to undesirable effects in some regions where it displaced native brook trout)

Answer 240

- Australia and New Zealand - done to make then more like Europe and N. America - e.g. many exotic species were introduced during 19th century, only 45% survived to become permanent residents (finding: if more individuals of a species were introduced, the species was more likely to survive and colonize the island)

Answer 241

- more releases increase the likelihood of success - small pops face a variety of chance events that can lead to extinction (bad weather or predator attacks that kill only A FEW individuals but tip the balance toward FAILURE)

Answer 242

YES - deer introduced w only 2 individuals was successful (e.g.)

Answer 243

- transport - establishment - spread - impact - invasion process can fail at ANY of the steps - final impact of invasive species may be large OR small, and the impact depends in part on human perception

Answer 244

- biological environment MAY eliminate the newcomer (predators may prevent the establishment of some species) - the physical-chemical environment may be LETHAL to the organism/prevent it from reproducing - seen with mussels. they disappear rapidly from protected waters (but are abundant in exposed waters) bc they are eaten by 3 species of crabs and a starfish, which are uncommon on open coast bc of heavy wave action. If kept in a cage in the protected waters, they will survive bc predators cannot get to them.

Answer 245

- AWAY (on average)

Answer 246

TRUE - not the case in reality though, bc many factors affect range limits.

Answer 247

- is species absent bc it has not been able to move to an area (dispersal limitation)? - is species absent bc it does not recognize the habitat as suitable? - do other species prevent colonization (parasites, predators, pathogens)? - are there limiting physical/chemical factors (temperature, water, oxygen, soil, pH)? - changes in distribution bc of CLIMATIC WARMING can be accepted ONLY if the 1st 3 questions are considered well

Answer 248

- The simple model for climatic limitation is that geographic ranges for ALL species should be shifting poleward. BUT, some move in opposite direction - one important concept in work on changing climate is to MAP the rate at which climates change in relation to the movement of GEOGRAPHIC RANGE (over time) - conclusions made from such studies DO NOT mean that same conclusions will be applied IF climate shifts (that is, the findings will occur faster)

Answer 249

- competition (e.g. use of chemical warfare by plants to suppress possible neighbours that may harm them)

Answer 250

- action of penicillin, the secretion of a fungus, on other microorganisms - a soil fungus excretes the antibiotic to protect itself against bacteria

Answer 251

- A study of colonization (by microorganisms) of new environments (people) - all ppl, at some point in their life, owe a debt to the chemical warfare of an antibiotic against some disease organism AND the restriction and elimination of the invading microbe in our bodies

Answer 252

stop herbivores from eating them!!

Answer 253

- they are constrained by stream GEOGRAPHY - plus, with water temperatures rising, the prediction is that stream fish will tend to move UPSTREAM to stay within their temperature zone (however, studies found that the rate of range shifting was not keeping up w the temperature changes within the streams, SO range shifts were lagging behind what is needed to adapt to ongoing water temperature increases)

Answer 254

- Mangroves (intertidal trees and shrubs growing around coastlines) - they have expanded their geographical range toward poles on five continents over the past half century, at expense of SALT MARSH - they have expanded into salt marsh in southern USA (and Peru and Mexico's Pacific coast) due to lower frost frequency there - expansion is still occurring - these changes are consistent w the poleward EXTENSION of temperature thresholds coincident w sea level rise (though SPECIFIC mechanism of range extension MIGHT be complicated by limitations on dispersal) - shift from salt marsh vegetation to mangrove dominance on subtropical and temperate shorelines WILL have effects on OTHER species in intertidal community (larvae from many species of fish rear in mangrove areas, for e.g.) - mangroves protect shorelines from catastrophic wave action during tsunamis (will effect environment eventually)

Answer 255

FALSE. Poorly understood. We recognize fauna and flora of dif continents well, but do less well at local level to understand for e.g. why particular plant occurs in one woodland but not in adjacent one

Answer 256

- geography - climate

Answer 257

- human introductions - climate change

Answer 258

FALSE. No plan. Trial and error. Fittest survives. Do not expect perfection. All selec does is select variants that perform a little better than the previous "model".

Answer 259

Bc animals w more acute hearing had higher fitness than others - have a fitness advantage, ears have adaptive significance

Answer 260

One that reduces fitness. Likely to be prominent in a changing environment, where new ecological challenges/opportunities change the fitness consequences of pre-existing characteristics. - e.g. humans' strong attraction to sweet/fatty foods was likely an adaptive trait in past environments where such energy-rich foods were rare, but in a modern, dough-nut-rich envi it has become maladative

Answer 261

- tradeoffs - constraits

Answer 262

- TRUE - e.g. ears could be used for hearing, and can be used for regulating body temperature - nothing in action of natural selec prevents traits from multitasking

Answer 263

FALSE. Does not.

Answer 264

Individual organisms are entities that succeed or fail, so adaptive evol of particular trait will depend on its OVERALL effect on fitness, though ALL its functions. - e.g. small ears on rabbits in cold environments reduce hearing (TRADEOFF), it is likely impossible to maximize both hearing and thermoregulation at once with ear shape, so compromise bw functions is seen

Answer 265

-tradeoffs permeate construction and function of orgs - some of most famous affect life-history traits - such traits concern timing of LIFE EVENTS - e.g. maturation and reproduction, amount of resources that individuals invest in such functions

Answer 266

- economic principle of allocation - states that resources invested in one function are unavailable to invest in other functions

Answer 267

- reproduction-survival tradeoffs (investing resources in offspring means they can't be used in maintaining the body) - size-number tradeoffs (if you make more seeds, they have to be smaller)

Answer 268

- evolutionary constraint - bc they reduce the range or kind of adaptation that one might otherwise see - plenty of other factor can constrain adaptive resources too

Answer 269

- large ears are delicate structures that would get worn and torn by life of animals that live in small crevices or rock or etc

Answer 270

- constraint posed y the wear and tear of the lifestyle of the animal (e.g. pika's rocky underground life)

Answer 271

- basic approach of examining how dif orgs meet environmental challenges in dif ways - is strongest when we know something ab how the species are related to each other (e.g. explanation of similar characteristics being inherited from common ancestor makes sense, could be close relatives, OR if species are distantly related, they share so many characteristics bc they evolutionarily CONVERGED under selec exerted on them, in this case, they had dif ancestors that were similar)

Answer 272

- phylogenetic trees - recently have been constructed from DNA sequences, greatly enhancing comparative method

Answer 273

temperature

Answer 274

- hot near equator, grading toward cold at poles - pattern arises from uneven distribution of radiant electromagnetic energy that comes from sun

Answer 275

TRUE - spherical shape means that sun's rays strike earth at dif angles at dif latitude - density of photons is highest at equatorial regions, where surface of earth is perpendicular to vector of incoming photons (perpendicular to sun's rays IF we average its position over course of a year, considering the angle shifts of seasons) - photon density per area declines as we move toward poles bc angle of incidence decline from 90 to 0 degrees, eventually reaching tangent, where rays skim parallel to ground at poles, not delivering any energy to surface but zinging ineffectually off into space

Answer 276

TRUE - sun is far enough from earth to consider this true

Answer 277

- very important to orgs - arises bc earth's axis is tilted at ab 23.5 degreesoff vertical - as it spins, dif parts of earth are exposed to sun

Answer 278

- at spring and autumn equinoxes, sun is directly above equator - at northern hemisphere's summer solstice, it is directly over 23.5 degrees N (tropic of cancer) - at winter solstice, it is directly over 23.5 degrees S (tropic of capricorn)

Answer 279

- tropical region ("tropics")

Answer 280

- line of latitude closest to sun - oscillates bw tropic of cancer and capricorn, making one cycle per year

Answer 281

- light is hardly absorbed by air - most of energy reaching earth from sun is in spectral range of light, and those wavelengths pass through air without giving up much of their energy to air molecules

Answer 282

TRUE - due to tilt of earth

Answer 283

- transfer happens when light hits surfaces other than air - when photons hit those surfaces, they are absorbed and reradiated at longer, infrared (IR) wavelengths - light is converted to heat - IR radiation is absorbed by atmosphere - earth's surface and then air near surface is heated

Answer 284

TRUE - IR radiation

Answer 285

- packs of hotter, lower density fluids are more buoyant than colder fluids above them, so they are propelled upward and cold fluid sinks - cycle, repeats

Answer 286

- atmospheric circulation patterns that are analogous to rolling turnover that we see in a boiling pot of spaghetti water - heating from top vs bottom (just vapour vs boiling)

Answer 287

- reduction in density causes a meteorological LOW PRESSURE ZONE - reduction in density impels heated air to rise above solar equator (as air rises, it tends to create a partial vacuum beneath it that suction causes surface air to be drawn TOWARD solar equator FROM north and south - new air also heats up and rises, setting up a CONTINUOUS FLOW - air cant rise forever, once it reaches top of atmosphere it is pushed away from solar equator, moving to south and north - as air rises, it expands bc there is less atmosphere to compress it, expansion of gas causes it to cool and become more heavy - air sinks, but bc its continually pushed to north and south, it descends NOT at equator, but at ab 30N and 30 S degree latitude - sinking air warms up - after descending, packets of air are pulled back toward solar equator where they converge and rise again - 2 continuous circulation loops are established, each ab 30 degrees wide - HADLEY CELLS

Answer 288

- adiabatic lapse rate - an extension of ideal gas law

Answer 289

EQUATOR, while air masses at higher altitude are moving in OPPOSITE direction

Answer 290

- zone of rising, heated air

Answer 291

30 degrees N and S of equator

Answer 292

TRUE - air that comes into ITCZ is humid, heavily laden w water vapour - as it rises and cools, much of water vapour condenses into liquid water clouds and falls as rain, when air descends, it comes down as hot, dry air - SO equitorial tropical regions are very rainy - as dry air from high pressure weather systems returns toward ITCZ, it picks up moisture from ocean and wetter tropical regions, setting up next cycle

Answer 293

- deserts - hot dry air - sun is beating down relentlessly out of cloudless sky

Answer 294

- the flows that move toward the poles initiate a second set of cells - not as strong/consistent as Hadley cells, but driven by same processes - creates rainy and snowy low-pressure zones around 60N and 60S

Answer 295

- high level flows toward the equator close the ferrell loops - the flows toward the poles set up a 3rd pair of circulation loops (polar cells) - weakest and most diffuse

Answer 296

- they redistribute heat - mostly bc they redistribute water (as vapour) from oceans to continents, without this, continents would be deserts

Answer 297

- TRUE - north wind blows FROM north TO south

Answer 298

- bw 0 and 30N = Hadley cells push air from N to S - bw 30N and 60N - Ferrel cells push air in opposite direction - bw 60 and North pole = polar cells impart flow to the south

Answer 299

bulges southward, bringing frigid arctic air flowing from the north

Answer 300

- Toronto weather usually blows in from prairies (arise bc air being pushed straight northward by Ferrell cell is passing over surface of spinning sphere, this produces a TWIST of wind vectors w respect to earth's surface - the CORIOLIS EFFECT, aka PSEUDOFORCE) - WESTerlies acquire latitudinal range of WESTerly component by coriolis effect - westerlies are beyond 30N or 30S

Answer 301

- earth is spinning rapidly on its axis, atmosphere near earth spins with it - going from equator to north pole, speed of earth's totating surface slows bc earth's diameter shrinks - wind direction is changed by Coriolis effect in W-E direction (acts against the N-S movement of cells)

Answer 302

- between equator and 30N or 30S - same idea but opposite twist in latitudinal belts - air is moving TOWARD equator so air packets fall behind their apparent target rather than getting ahead - known as trade winds bc were very important to maritime commerce in sailing era

Answer 303

- at latitudes in middles of atmospheric cells (roughly at 15 and 45 degrees) - there, air is primarily being pushed HORIZONTALLY across earth's surface, producing consistent winds

Answer 304

- upward is at 0 and 60 degrees - downward is at 30 dgerees - there is little horizontal wind here and it is very fluky - feared by sailors bc they could get stuck there for weeks

Answer 305

- windless equatorial area - ships could be stuck here for weeks too

Answer 306

- windless area at 30N and 30S - ships could be becalmed for weeks here

Answer 307

- at around 45S, winds are too strong - prevailing westerlies are too fierce - so powerful and relentless bc there are no significant land masses in vast sourthern oceans - in north forties, continents interrupt and dissipate flow (very bad)

Answer 308

- concentrated and narrow westerlies - wander around in irregular fashion - as they wobble around, they blur and transgress the usual boundaries bw cells

Answer 309

- northern polar jet stream - can form at boundary bw Ferrell and polar cells

Answer 310

associated w some rogue loop in jet stream - e.g. between 30 and 60 degree N latitude, we experience prevailing westerlies, but there is rlly bad winter strom called a "Nor-easter", which drives DOWN Arctic air from northeast

Answer 311

FALSE - generalizations ab climate patterns in certain latitudes refer to LONG TERM AVERAGES

Answer 312

- temperature - precipitation

Answer 313

- just as air packets of dif temps rise and fall in gas atmosphere, producing directional flows, so do massive packets of water produce circulation patterns (CURRENTS) in oceans - what goes on in oceans definitely affects neighbouring land masses (land and sea are NOT independent systems, e.g. Britain's mild winters due to strong currents of Gulf Stream vs. Labrador's frigid winters, global warming may disrupt Gulf Stream making Britain very cold)

Answer 314

- aside from moving heat, oceans also influence nearby land masse by providing thermal inertia (land heats up in summer and cools down in winter much faster than water) - spring arrives more slowly in coastal areas, peninsulas, and islands than centres of continents, but summer lingers - ocean influenced MARITIME CLIMATES are buffered AGAINST temperature extremes (frost sensitive crops are often here bc sudden freezing is less likely - CONTINENTAL climates lack water dependent buffering of temp (summers are hotter and winters more frigid)

Answer 315

TRUE - it is distorted by the great annual temp swings produced in large continental mass of ASIA

Answer 316

TRUE - in tropics, temps are comparatively uniform, and seasonality is a matter of precipitation - in a few placed, ITCZ barely moves, creating almost uniform rainy climate throughout year (archetypal tropical evergreen rainforest) - in other parts, ITCZ swings over large range of latitude, producing one or two discrete rainy seasons as it passes over, separated by dry seasons when it moves away

Answer 317

- air that gets loaded w water vapour by passing over oceans - much more loading takes place when ocean waters are WARM rather than cold (warm water warms the air, water is better able to vapourize, warmer air can retain more water vapour) - thus, when winds carry ocean derived water vapour onto land masses, they will bring much more potential rain if those winds have been blowing over WARM water - clearest example of this effect is seen in where driest deserts are found (desert concentrated at 30N and 30S, but most extreme are located on WESTERN coasts of continents, each paired w cold offshore current that brings an upwelling of water from cold depths. thus, primary potential sources of precipitation for these areas are all sarved of water vapour, Canary Current gives rise to western Sahara desert)

Answer 318

sharp difs in rainfall

Answer 319

- mountain generated precipitation - cause extreme biological and cultural phenomena such as snow in Costal BC and lots of vegetation in Olympic Range - due to rising cooling air that creates more precipitation) - generated precipitation is left behind in mountains, while air keeps going east - as now-dry air descends eastern (leeward) slopes of Cascade Range, etc. it warms up from compression (lapse rate) and from friction (this is now DRY and DESICCATING air, similar in quality to descending Hadley cell air that creates deserts at 30, but more local phenomenon) - as dry air continues moving east across dry intermountain west, it can pick up moisture from vegetation and additional air flows from north/south - soon enough, air bumps into more mountains and cycle is repeated

Answer 320

- rain starved region that results from dry desiccating air - full of xeric vegetation that ranges from short grass prairie to near desert - NO giant plants on this side of range

Answer 321

- bc Rocky mountains create such a long north-south rampart - much of the hot, dry west and southwest is watered by rivers, not by local rain (rivers have water only bc they are fed by meltwater from winter snows that fall in rockies)

Answer 322

- in Rockies, all other dry areas, permanent rivers support narrow bands of richer, taller vegetation along their banks - if you see line of cottonwood trees, winding across an otherwise treeless landscape, you know there's a river there

Answer 323

TRUE - bc winds are often MORE consistent on oceans than on land - one end of island could be mossy dripping rainforest while other is dry grassland w beef grazing and plantations - is dry part on west or east end?

Answer 324

- sun - in northern hemisphere, south-facing hillsides face direct, parching rays of sun for most of day, north facing slopes are mostly shaded, cooler and more moist. Vegetation on slopes w dif aspects usually differs sharply

Answer 325

Autecology

Answer 326

- conditions (physical states that cannot be depleted, such as temp or pH) - resources (necessary physical entities that orgs use up, can be depleted, e.g. water, chemical nutrients, space)

Answer 327

- factors most important in determining whether a species can/cannot persist in an area

Answer 328

- at broadest level, the 2 factors that are MOST likely to limit the distributions of terrestrial species are temp (condition) and water (resource) - for terrestrial orgs, water availability ultimately depends on PRECIPITATION, so WEATHER and CLIMATE are most important determinants of what sorts of orgs are found in dif parts of world

Answer 329

- standard concept - simplest sort of gradient would occur along line drawn across real habitat (e.g. shore lake (where soil is saturated w water) toward higher ground (soil gets drier as you walk away from water source) is the gradient of soil moisture, plants will sort themselves out along gradient based on type of soil they prefer) - any factor (temp, pH, salinity, etc.) can be treated and tested as gradient

Answer 330

- altitude (elevation) - considered a complex gradient bc many simpler factors vary w altitude in nature (temp, precipitation (amount and type), partial pressure of oxygen, etc.) - bc many of these factors are critical to success or failure or orgs, most species in montane regions are RESTRICTED to well-defined ranges of elevation, tempered by exposure

Answer 331

LIMITING FACTOR - that portion constitutes RANGE OF TOLERANCE for that particular factor, can be considered as a defining part of niche of that species

Answer 332

LIMITING FACTOR - that portion constitutes RANGE OF TOLERANCE for that particular factor, can be considered as a defining part of niche of that species

Answer 333

- as curves that show how an orgs ability to function changes along gradient - in abstract depictions, they are usually represented by bell-shaped curves, tho real tolerance curves may have very dif shapes - regardless, it peaks at some point, where the envi is optimal for org to thrive - the farther you get from optimal, the closer to death zone

Answer 334

- hydric (wet, waterlogged) - xeric (dry) - mesic (intermediate)

Answer 335

TRUE - resistance is limited

Answer 336

- affects concentrations of chemical reactants - bc cells and tissues depend on membranes to compartmentalize chemical processes and reactants - proper functioning depends on osmotic balance

Answer 337

TRUE - physico-chemical reason has 3 parts: (1) environments contain far broader range of physical conditions than much narrower ranges of tolerance that characterize orgs (death zones ARE out there), (2) things tend to equilibrate i.e. reach same temp as envi, (3) environments are much larger than orgs, so equilibration is asymmetrical (e.g. warm animal in cold climate will get colder as envi gets warmer, animal loses a lot of heat relative to itself, envi's heat gain is nothing compared to energy in system)

Answer 338

- thermoregulation (maintaining temp) - osmoregulation (maintaining saltiness) - capabilities of orgs in doing these depends on body size and shape

Answer 339

Paramecium in freshwater pond has high Sa/V ratio bc its small. Any small amount of heat it generates are instantly sucked away by overwhelming mass of water. BUT pond temperature dont reach extremes so the org can get away w being THERMOCONFORMERS rather than THERMOREGULATORS. - warm blooded animals (mammals and birds) tend to exhibit active regulation of heat balance to keep body temp constant, despite great fluctuations in ambient temp - cold blooded animals (fish, reptiles) tend to be thermoconformers whose body temps more closely track ambient temps

Answer 340

- expenditure of energy on regulating homeostasis - e.g. squeezing water out of paramecium body requires energy to counteract unrelenting passive inward pressure of water

Answer 341

- large bodies - complicated metabolisms

Answer 342

- stresses constancy of body temp vs. variability

Answer 343

emphasizes that temp is primarily determined by physiological processes acting WITHIN the body vs. to being determined by external envi

Answer 344

- TRUE - e.g. if you stand in an icy flowing stream, cold water not only extracts heat from your feet in conduction-like process, but current sweeps the slightly heated water away, so equilibration is MINIMAL

Answer 345

TRUE - water has high specific heat than any other common material of ecosystems - cold water sucks heat out of warm animal VERY effectively - also has high heat of evaporation (meaning that evaporation from moist surface is very effective means of cooling that surface

Answer 346

- does not involve molecules bashing in each other and transmitting their kinetic E - fire heating only part of you that is facing it, not your entire body

Answer 347

- vertebrates generate a lot of heat from internal metabolic functions, esp muscle contractions (e.g. shivering is effective way to increase internal heat production)

Answer 348

TRUE - large size is pointless in tropics just as small in arctic - Bergmann's rule (SIZE)

Answer 349

FALSE. Would NOT. - Allen's rule (SHAPE) - mammalian ears should be more "free" to register evol effects of Allen's rule than legs (think rhinos leg to body size proportionality) might be - birds wings, in constrast, might be expected to be HIGHLY constrained by their need to function in flight

Answer 350

- the same heat conservation advantages that can be achieved by growing larger could also be achieved by adding insulation (in cold climates this would seem to be energetically cheaper and evolutionarily easier than growing a larger body w all the redesign that would be required)

Answer 351

- through dead air spaces within the material - air is a great insulator if prevented from moving - real role of fur/feathers is to trap air and thereby prevent convective flow - within layer of insulation, a TEMP GRADIENT is set up and maintained: temps are cold near outside of fur and warm next to skin

Answer 352

- both comprise 1000s of modular structures that can be replaced as they wear out, so insulation doesn't degrade - animals can grow insulation that is appropriate to colder/warmer times of year - insulation system is very effective IF there is enough high-E food to run an orgs (that doesnt fit into climate) fast metabolism

Answer 353

- they are able to keep their fur/features temperatily waterproof by oil secretions and preening - for larger mammals that are always immersed (e.g. dolphins, whales), fur would become waterlogged and impede swimming (these animals depend on blubber)

Answer 354

- insulation of critical organs - long term storage of food energy

Answer 355

continuous temperature gradient bw the 2 vessels - thus, transfer of heat continues along entire length of paired vessels

Answer 356

TRUE - sweating - panting - evaporative cooling through respiratory system by birds

Answer 357

- seeds they eat contain very small amounts of water - REAL TRICK is to subsist on "metabolic water" produced by oxidizing the dry food they eat - have very efficient kidneys, nitrogenous waste can be eliminated through urine with minimal water loss - behaviour too, they are noctural, day is spent in burrows that are cool and moist

Answer 358

- angiosperms have seeds enclosed within their fruit, flowers provide protection for ovule - gymnosperms have no flowers or fruits and have naked seeds on surface of their leaves

Answer 359

evaporative cooling - this may generate tradeoffs in animals

Answer 360

- for photosynthesis - harvest essential photons - for gas exchange - but, this makes leaves vulnerable as they are in direct exposure to sunlight, making it more likely for them to heat up and cause proteins to denature - leaves use evaporative cooling to prevent overheating, for this, large supply of water is needed from moist soil and moves into roots and throughout leaves

Answer 361

photorespiration (waste of E created by photosynthesis)

Answer 362

- third major photosynthetic pathway - provides extreme water conservation, mostly in succulent plants - path is instructive bc it consitutes a breakthrough that eliminates a seemingly unavoidable tradeoff - CAM plants keep most of their stromata closed during sunny periods, minimizing water loss - having thick succulent leaves (or photosynthesizing stems) that are loaded w water, they have enough thermal inertia to resist overheating that would occur w thin leaves - CAM plants can capture co2 and store it in vacuoles as an organic acid intermediate until next day when sun's photons are available and light energy can be converted into sugar

Answer 363

- airflow is important too - leaf that is swept by wind receives continually refreshed supply of co2 and was o2 is dissipated. if air is not moving, stagnant air builds up next to leaf. dead air gets depleted of desirable co2 and enriched in undesirable o2. it is also likely to heat up bc convective evaporative cooling is reduced - all these things are detrimental

Answer 364

TRUE - happens when surface is smooth, without bumps that air has to detour over - when airflow is unimpeded, a stratified pattern builds up (LAMINAR FLOW) - friction w leaf's surface alows air movement to a crawl - gas exchange within this still, stagnant boundary layer occurs only by regular molecular diffusion, it gains nothing from wind passing above

Answer 365

layers of air that move at dif speeds - e.g. farther from a leaf, air will be going at a speed, closer to the surface, air forms a boundary layer that is virtually stagnant

Answer 366

- if leaf surface has enough irregularities, smooth laminar flow turns into TURBULENT FLOW and boundary layer is broken up and freshened by eddy currents and vortices - turbulence is usually desirable on a leaf, many leaves have this (e.g. oak trees) - in addition to other functions of stiffening the lead and circulating water, nutrients and photosynthate veins of leaves help induce turbulent air flow

Answer 367

TRUE - via induction of turbulent flow

Answer 368

- water harvesting - storage - best displayed in subtropical, seasonal deserts that get rain rarely

Answer 369

- shown by giant saguaro cactus (its accordion-pleated stems allow it to expand without bursting while it is imbibing after rain) - by end of dry season, cactus's girth shrinks a lot - in midwestern prairies, most plants have very deep root systems that seek out water deep in soil (soil acts as an EXTRNAL STORE or bank of moisture from which plants make needed withdrawals) - in deserts, there is no water in soil most of the time, plants there have very shallow root system, their function is to suck up rainwater as soon as it falls so that other plants dont get it first (here, cacti themselves function as the bank, they tank up w water whenever it is available and can call on that internal store as needed)

Answer 370

TRUE - have compressed life cycle in which seeds germinate right after heavy rains start - they grow, flower, set seed and die in 2 months ish - these plants temporally evade desert conditions by growing during BRIEF interludes of non-desert life conditions - they dont have many extreme anatomical/physiological adaptations to dry conditions

Answer 371

microphylly (tiny leaves) - these dont expose large area of photosynthetic tissue to sun and they are often arranged in ways to produce turbulent airflow - fairly thick for their size, which gives them more thermal inertia - some are evergreen, others drop their leaves in dry times of year

Answer 372

TRUE - leaves modified into thorns, abandoning ancestral function of photosynthesis and taking on new protective function - a plant that adopts a policy of banking its own water supply needs to PROTECT itself against bank robbers

Answer 373

- characteristic of having leaves that are small, thick, tough and leathery and almost always evergreen - often contain essential oils - e.g. pine needles - angiosperm sclerophyllys have leaves that are wider than conifer needles but are still rather narrow and simple in shape - sclerophyllous leaves are in many respects opposite of large, thin delicate leaves that characterize deciduous forest biome (e.g. maple leaves)

Answer 374

- semi-submerged plants in acid bogs and ponds in dif temperate habitats - cold boreal forest biome, a snowy envi w reasonable amounts of summer rain and soil moisture - in very dry, well-drained sandy soils in warm habitats from southern US to central and south america and equivalent habitats in Old World (?) - Mediterranean/chaparral biome with wet but not snowy winters and very dry, hot summers

Answer 375

Arthropods, animals w jointed legs. Basic insect body plan has 3 sections: head, thorax, abdomen.

Answer 376

- trait is heritable - there is variation bw individuals within a pop for the trait - variation in trait leads to some individuals leaving more offspring in next gen than others (higher fitness)

Answer 377

- complete: egg, larva (caterpillars which feed on vegetation and grow), pupa (caterpillar attains full size, it assumes a dormant and nearly immobile form of pupa, in a protective cocoon), adult (develops in cocoon, once done transforming, butterfly breaks out of cocoon and dries its wings, feeds on flower nectar and can reproduce) - incomplete: egg, nymph, adult - incomplete metamorphosis is LESS effective bc there are more individuals competing for SAME resources - 4 insects go through complete metamorphosis: beetles, true flies, bees, wasps, ants, butterflies and moths - advantages of complete metamorphosis: no competition for food bw stages, increasing likelihood of survival. also, such insects are likely more developed, as they went through growth process for longer

Answer 378

- industrial melanism peppered moth - bright colour skin - camouflage (orgs benefit by physically resembling their envi, less visible to predators) - life in water (aquatic insects have bodies/legs specifically shaped for water life) - feeding (specializes mouthparts - powerful jaws, tube for piercing and sucking, long "tongue")

Answer 379

- sexual selec often results in evol of difs bw males and females - such a dif bw sexes in shape/size of body is SEXUAL DIMORPHISM - e.g. bugs w horns in males is only competition of mates adaptation and NOT viability bc its present in ONLy one sex (must be present in both sexes for viabiltity)

Answer 380

- INTRAsexual competition: males fight w other males for access to females. male that defeats his rivals in combat will probably sire more offspring - mate CHOICE: thought to increase fitness of "chooser" by enabling it to mate only w healthy individuals (more attractive mates). attractive individuals tend to acquire more mates and produce more offspring

Answer 381

- adults have proboscis (mouthpart) while caterpillar have mandibles they use for eating - possible adaptation is bright wings? - monarch butterflies have effective chemical defense. when they feed on milkweed plants, they isolate cardenolies in milkweed which are poisonous to their predators. However, this doesnt help the butterfly AFTER a predator already tried to eat it. Through smell of isolates cardenolides, as well as through colourful wings, which predators recognize as danger monarchs warn off predators to prevent being killed.

Answer 382

- they capture small insects entrapped by water's surface tension - have excellent eyesight, which helps them find prey - 3 adaptations that enable them to move on water surface: fine hairs all over body and legs, very thin light legs and body, spread out legs that disperse their mass over larger area - have 3 pairs of legs, but only middle set of legs is used in locomotion. first and last are used for balance of body and dispersion of body mass over greater SA - mouthparts: pierce their prey through water (water acting like web for spider catching food) by using labium

Answer 383

- in one species, males prefer longer females as mates, probs bc they produce more and larger eggs - females are capable of asexual reproduction (parthenogenesis), such eggs take longer to develop than fertilized eggs - preyed upon by birds and small mammals - camouflage allows to blend in w its envi and protect itself from predators - females are larger, more leaf looking and wingless. Likely bc female bodies are made w goal of reproduction in first place so body is larger and thus more E is focused on eggs - wings in males, used for flight, are often brightly coloured to ward/scare off predators and communicate within the species - behavioural adaptations include staying very still too look as stick/leaf life as possible, allowing them to blend in w their envi better acting as protection - Australian leaf insects can curl their tail over their bodies and snap their back legs in case of predator attack, protecting herself and more importantly, eggs

Answer 384

- males larger than females and have bumps on dorsal prothorax which serves as plate that protects head - males defend territories, fending off rivals by lunging at them and pushing them away - typical mouth - evol of hissing response: to scare off predators that attempt to eat them - for combat w rival males, male cockroaches lunge at rivals and push them away to defend their land. adaptation for viability bc used for protection but present in only one sex

Answer 385

- beetles thought to be largest insect order - males have much larger mandibles than females bc of viability adaptation, to protect themselves in combat w other males, females dont need this trait - stalk eyed flies have eye stalks to be used for both viability and mating, very small so good eye sight necessary for survival - male rhino beetles do not continue larger horns bc they make general lifestyle more difficult, plus they simply dont need them as their current horns offer all the necessary protection from predators and others of same species

Answer 386

- in some species of water bugs, female deposits her eggs on back of male who carries them until they hatch (e.g. of paternal rather than maternal care) - mantids use "sit and wait" preying method - water bugs adaptations for life in water include their overall body shape (long and flat) which allows them to easily travel through water creating minimal resistance - water bugs and mantid adaptations for capturing prey are that they have similar techniques for capturing prey as they both puncture their prey w a structure in mouthpart prior to consuming prey - mouthparts of the 2 differ in that mantids have longer structure to puncture prey, likely for evolutionary reasons

Answer 387

- trait studied was nymphal camouflage, i.e. backpacks and dust coats - hypothesis: effect of backpack and dust coat on encounters with prey as well as with predators, i.e. if it helps bugs survive/feed - diet of bugs consists of ants, known from types of species that appear on their backs - dust coat made up of dust, sand and soil particles. it impedes chemical and tactile recognition of nymphs by ant workers and thus may serve to incr hunting success - backpack made of larger objects such as empty corpses and plant parts attached by fine elastic threads secreted by specializes gland hairs on dorsum, appears to play only MINOR role in increasing hunting success - backpack and dust coat on abdomen, and give bugs appearance of an unpromising food object - camouflaged bugs are significantly more likely to survive - adults can be apterous (wingless) or macropterous (with fully developed wings) - in encounters, dust coat had concealing effect for prey, and backpack offered nymphs protection from predator attacks - the bugs have flat bodies and their backpacks stick out from surface, making them conspicuous to any predator hunting by sight and confuse them, reduce risk of being attacked - bugs w backpacks did not receive more attention that the dust coat and naked one - dust particles attached to nymph' bodies probably mask the olfactory and tactile signals that would give away the bugs identity as living things, thus dust coat is a form of CRYPSIS, operating not in visual but in other sensory modes - backpack is NOT necessary to prevent prey recognizing them - backpack is an effective means of diverting a predator attack that functions in a similar manner as a lizards tail as they drop their backpack to escape predators, its a protection that can be restored quickly and at much lower costs

Answer 388

- phenotypic plasticity: single genotype can produce dif phenotypes in response to its envi, when an individual can alter the expression of a phenotypic trait in response to envi, can express itself as EITHER discrete alternate type of in a continuum - overall phenotype composed of its morphology, behaviour and physiology - variation may result from variation among genotypes (gen variation), the envi, or interactions of these 2 components - alteration of the phenotype (acclimation) occurs in individuals that are able to modify their phenotype in response to environmental variation in a way that improves fitness - limitation associated w new phenotypes is accuracy w which an org can correctly process envionmental cues to appropriately acclimate (may produce maladapted phenotype), ALSO the time dif bw sensing environmental change and alteration of phenotype (individual experiences reduced fitness bc not yet acclimated, the greater the change the longer the time lag) - phenotypical plasticity, the observed trait ITSELF is not heritable bc dif phenotypes are produced by same genotype, BUT ability for a TRAIT to plastic is heritable

Answer 389

acclimate, it is populations that adapt to changing envi

Answer 390

- discrete: one or another (colour for e.g.) no in bw - continuum: when expressed like this, relationship bw envi and trait is known as reaction norm

Answer 391

- insufficient gen variation exists - there are inherent costs and limitations to the benefits that plasticity may provide - costs associated w producing new phenotypes and maintaining sensory and regulatory mechanisms required for plasticity may offer a significant selec pressure against the evol of plasticity of a trait - linkage bw genes might produce a situation whereby genes promoting plasticity migt be linked to genes conferring a low fitness for other traits

Answer 392

- stridulation is creating sound by rubbing together 2 body parts (both males and females do this) - uses sit and wait hunting strategy which is caught by modified front legs, paralyzing and digestive enzymes are injected into prey and liquified body tissues are sucked out - the bugs have 2 types of light sensing organs: compound eyes and simple eyes (ocelli)

Answer 393

- aka dissecting microscope - provides 3D view of object (compound provides 2D) - can separate light paths for each eye piece, the slightly dif angles seen create 3D image - generally have less magnification power - the greater distance bw objective lens housing and stage plate allows for viewing and better manipulation of specimens - ocular micrometer is small glass disc inside ocular on which uniformly placed lines of unknown distance are etched, calibrated against rule (w known distance bw lines)

Answer 394

- plants produce proteins called phytochrome, a photoreceptor that detects shading by other plants - classic e.g. of phenotypic plasticity in plants is adaptation of leaves to sun and shade conditions - green light is transmitted from leaves, blue and red absorbed - plants growing underneath others receive reduced amounts of red light. it is the reduced ratio of red light to far red light that elicits a phytochrome response which detects not only light quality but regulates gene expression - hypothesis: the greater amount of exposed sunlight (indep variable), the greater thickness of leaves (dep variable). - upper epidermis is contiuous layer of transparent cells, small amount of light is absrobed - palisade mesophyll is directly under upper epidermis and is composed of elongate sausage-shaped cells that carry out most of photosythesis, arranged in distinct rows, individuals of some plants can alter the # if layers of these cells depending on light intensity and quality (one possible explanation for elongate shape is that it keeps individual chloroplasts from overheating, each moves into direct light and then down into shaded part of cell and up again by stirring of the cytoplasm) - stomata (pores through which gas exchange and water evaporation occur) - veins and vascular bundles contain xylem which carries water to photosynthetic mesophyll cells AND phloem which takes carbohydrates produced by photosynthesis in mesophyll and transports it to rest of plant - spongy mesophyll cells also carry out photosynthesis, usually more air space visible bw cells of this layer so more air that is in direct contact w stomata, abundant small chloroplasts - LAB DATA: sun plants were much thicker (352 picometers vs 277 for shade). Leaf thickness is a phenotypic trait bc plants express thinness vs. thickness of leaves depending on envi in which they're held. Leaf thickness is adaptive bc depending on how much E the plants receive from sun, they adapt to how they grow to better split use of their E among entire body. Phenotypic variation in both the plant and ambush bug bc orgs arent identical to each other. BUT leaves express plasticity while bugs dont their traits vary by genotype while the leaf traits vary by envi

Answer 395

- magnification of objective lens by adjustment knob is changed by revolving nosepiece - there are 2 focus adjustment knobs (fine and coarse) on compound, just one in stereo - stage can be moved up and down on compound, w stereo lenses and their components can move up and down - light shines from below stage on compound and above the stage on stereo

Answer 396

- magnification of compounds microscope is magnification of objective lens TIMES magnification of ocular lens - in compound microscope, scale of image decreases as magnification decreases - 4x = 40 ocular spaces, 1 mm on stage - width of 1 ocular space is 0.025 mm - 10x = 100 ocu spaces, 1 mm on stage = 0.01 mm width of 1 ocular space

Answer 397

- competition (-/-) interaction is negative for both sides, usually bc both require same resources - mutualism (+/+) both benefit - consumer resource (+/-) one benefits (consumer) the other suffers a cost (resource) (e.g. predaotr and prey, parasite and host)

Answer 398

- indirect: transmitting viruses bw plants through mouthparts and saliva - direct: consuming and killing seeds of plant

Answer 399

- timing of flowering or leaf production - structural defenses - chemical defenses

Answer 400

- phenology is study of life cycle of plant and animals in relation to seasonal change - plants can defend themselves from herbivore damage by producing leaves/flowers when herbivores are least abundant, they may also present their flowers/leaves simultaneously instead sequentially (reduces damage bc less leaves available to be eaten by predators) - some plants have trichomes on stem and leaves as a defense mechanism, they trap herbivores, prevent them from laying eggs or make it difficult for them to feed on leaf tissue - goal: test effect of damage on expression of chemical defense (polyphenol oxidase, PPO) and structural defense (trichomes) - PPO = enzyme stored in plants, released in response to damage, oxidizes to make quinones that lead to reduction of nutritive quality of plants and breakdown of essential amino acids in gut of herbivore when consumed - PPO activity = (final A- inital A)/time / leaf mass - trichome density = # trichomes in FOV/diameter of FOC (mm) - results: PPO activity greater for damaged plants, no significant difs in trichome density (maybe not enough time given for them to develop). Results show that PPO for sure and trichomes (maybe) are plant defenses bc damaged plants had defensive actions that control plants didnt

Answer 401

- constituitive: defenses that do not significantly change over time - induced: produced/increase their level of expression following damage by herbivore, may arise from signalling cascades within plant (occurs when one chemical is produced in response to wounding which results in creation of a variety of other chemicals that cause production of dif defencses (physical and chemical)

Answer 402

- glandular: have gland on top of their stalk that contains chemical that is released upon contact - non glandular: lack glands

Answer 403

- observing outside world through out senses - asking questions about natural phenomena that interests us (the type of questions asked should lead to clear hypothesis that may provide insight into our observations, important to choose right ones as they influence everything that follows, good hypothesis makes testable predictions) - hypothesizing an explanation for phenomenon (statement, not question, influenced by scientist's experiences, prior knowledge and imagination, way it is constructed allows for gathering of data that can refute or support idea, is NEVER proven, only disproved) - testing hypothesis through experimental or correlational study - collecting and analyzing data from experiment (chi square test and t test, simply knowing results is dif from interpretting them) - creating conclusion from experimental data - each step is intuitive, steps are often cyclical, we use the method as a way to objectively study natural phenomena - null hypothesis used to provide support or not for hypothesis

Answer 404

- correlational: uses naturally occurring variation to investigate effect of one factor on another, nothing about system is being altered, nature is observed, use NATURAL variation, no independent and dependent variables bc this study looks at association of 2 variables, not dependency - experimental: alter study system and measure effects of manipulation, use ARTIFICIAL manipulation - advantages of correlational: less handling or orgs which could harm the org, systems more likely to be observed in natural state , represent biologically relevant variation, there are situations where exp manipulation isnt ethical or practical - advantages of experimental: more likely to control for confounding variables, we know direction of causation

Answer 405

when it has been supported by substantial amount of accumulated evidence from many studies and has been shown to be reliable within carefully specified limits - this level of support and reliability gives theories a very broad perspective value - theories that have been tested and shown to be universally valid are NATURAL LAWS - hypothesis, theories and natural laws are under constant scrutiny and can be accepted, without modification, only for as long as they represent the BEST general predictive statement that is supported by all experimental evidence - any physical theory is ONLY a hypothesis, you can never prove it no matter how much experimental data backs it up

Answer 406

- accurately describe large class of observations - make definite predictions about results of future observations

Test 2 Flashcards

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