Definitions Flashcards
(168 cards)
1
Q
Proximate Causation
A
Immediate or short-term cause of something
Example: How does the male cardinal get its red color? What is the current role of mitochondria?
2
Q
Ultimate Causation
A
Why something exists the way it does.
Example: Why is the male cardinal red and not the female? When did mitochondria originate.
3
Q
Evolution
A
Descent with modification.
1. Change in genetic composition of populations.
2. Cumulative changes in traits.
Requires genetic variation!
4
Q
Diversification
A
New species
5
Q
Microevolution
A
Generation-to-generation changes.
Example: What are the causes of evolution.
6
Q
Macroevolution
A
Long-term changes above the species level (historical patterns)
Example: What has been the history of life on earth?
7
Q
Mutation
A
- Error in DNA replication
- Ultimate source of all genetic variation
- CONTINUOUSLY SUPPLIES NEW ALLELES
- Single gene mutation low, genome wide high
- Arise stochastically not deterministically
8
Q
Macromutations
A
Changes in chromosome or gene number.
Example: Deletions, duplications, translocations, inversions, fusions, point mutations.
9
Q
Inversion
A
ABEDCF
Example: Orangutan inversion.
10
Q
Fusion
A
Example: Human 2 fusion
11
Q
Recombination
A
- Shuffles new genes into new combinations
- Increases variation of how genes are packaged
- Do not change in a short time scale
Example: Independent segregation, crossing-over.
12
Q
Genetic Drift
A
Random changes in allele frequencies due to sampling error.
1. Major short-term cause of changes in allele frequencies
2. Depends on population size
3. Causes a loss in genetic variation
Example: Elephant seal, Greater prairie chicken.
13
Q
Bottleneck effect
A

14
Q
Founder effect
A
Founders carry unusual allele frequencies by sampling error alone.
- Form of genetic drift
- Important for some cases of speciation
15
Q
Spatial subdivision
A
Patchy food, nesting sites or habitat
16
Q
Gene flow
A
Movement of individuals or gametes between subpopulations.
1. Counteracts effects of genetic drift
2. Can speed up or slow down adaptive change
3. Prevents local adaptation
Example: Prevents insects from adapting to pesticide if some farmers spray. If all farmers spry then can spread favorable allele to all populations.
17
Q
Hardy-Weinberg equilibrium
A
Allele and genotype frequencies remain constant between generations because it is a non-evolving populations characterized by:
(1) no net mutations, (2) no genetic drift (infinitely large pop), (3) no gene flow (pop isolated), (4) random mating and
(5) no natural selection)
18
Q
Natural Selection
A
ONLY process that produces ADAPTATIVE change
Requires 3 conditions:
1. Phenotypic variation
2. Fitness differences
3. Variation in genotype
Cannot predetermine what is most useful—can only adapt to current challenges
A NON-RANDOM PROCESS
A compromise of traits that reflect historical constraints (TINKERER not engineer)
Example: Example of constraint of natural selection: Bipedalism in humans, lungs connected to stomachs in mammals, retrofitting of the testicles, laryngeal nerve in humans and giraffes, vestigal femur bone in whales and hind limb bones in snakes, mammal eye vs mollusc eye (evagination of brain vs invagination of epidermis)
19
Q
Fitness
A
A measure of reproductive success
20
Q
Directional Selection
A
Example: Guppie size in streams with or without predators, beak size of Soapberry bug in Flordia.
21
Q
Disruptive Selection
A
Example: Bill size in African finches.
22
Q
Stabilizing Selection
A
Example: Gall size of Gall fly, birth weight of human babies.
23
Q
Juvenilization
A
Artifical selection for more juvenile like features.
Example: Wolf to dog, cattle reduced size, silver foxes breed for tameness.
24
Q
Artificial Selection
A
Breed for a predetermined goal or path.
Example: Wild mustard cultivated into eatable kale, broccoli, cabbage, etc.
25
Pleiotropy
Single gene affects multiple traits.
| Example: Fruit fly: bigger body size gene is same as longer egg-to-adult development time gene.
26
Sexual Selection
Heritable differences in ability to find mate of opposite sex.
Example: Exceptions that prove rules: Male katydids carry eggs while developing— females are much bigger. Male Phalaropes care for young, females much brighter and bigger.
27
Intrasexual Selection
Male-male competition (direct competition for mates).
Example: Explains behavioral/morphological traits:
(antlers, territorial behavior), post- copulatory sperm competition.
28
Anisogamy
Different investment per gamete.
| Example: Post-zygotic care by females much higher.
29
Male
Produces many gametes (low investment).
30
Male
Produces many gametes (low investment).
31
Females
Produces few well-provisioned gametes (high investment).
32
Monogamy
One partner for entire reproductive life.
33
Polygyny
One male multiple females.
| Example: *Sexual dimorphism (difference between sexes) is greater in polygnous species than in monogamous species.
34
Polyandry
One female multiple males.
35
Polygamy
Multiple partners for everyone.
36
Speciation
Populations that could once interbreed no longer can Requires:
1. Interruption of gene flow which causes isolation mechanisms.
37
Taxonomic species
Category of classification, generally determined by morphology.
38
Biological species
Species that can interbreed but are reproductively isolated from each other.
39
Prezygotic barriers
An isolating mechanism that prevents successful mating and fertilization.
Example: Habitat, temporal, gametic, behavioral (for species with specific mate- recognition systems), gametic
*Single gene causes mechanical isolation in land snail
40
Postzygotic barriers
Fertilization occurs, hybrids are inviable or infertile or break down after a few generations (can have parital barriers, one cross fertile the other isn’t).
41
Allopatric speciation
Caused by geographical seperations (glacier comes through, climate change, etc).
Example: Uplift of panamanian land bridge creates different lobster species.
42
Dispersal-mediated speciation
Pregnant lizard gets pulled out to sea and ends up on an island.
43
Vicariant speciation
Geographical change causes species to be seperated and change.
Example: Desert pupfish.
44
Ring species
Occur when ancestral population expands around a barrier. Gene flow is limited between populations. Closed ring, ends can't breed.
Example: Western US salamader.
45
Sympatric speciation
Interruption of gene flow, generally in plants due to polyploidy.
46
Polyploidy
Increase in # of chromosomes.
47
Autopolyploidy
Double number of chromosomes.
| Example: Potato, alfalfa, goatsbeard.
48
Allopolyploidy
Messed up chromosomal segregation changes number of chromosomes
More common.
Example: Cotton, tobacco, wheat, Marsh grasses (Spartina spp.)
49
Systematics
Establishes genealogial relationships among organisms.
50
Phylogeneic trees
Assembled around shared derived characteristics *have free rotation around each node.
51
Homology
Common ancestry means some species have same characteristics.
Example: Arms of human, cat, whale and bat.
52
Homoplasy
Caused by convergent evolution--traits evolved independently of each other
Example: Tasmanioan wolf tiger.
53
Paraphyletic
Grouping where one member is more related to some one else than the rest of the group.
54
Monophyletic
Grouping where everyone equally related.
55
Stromatolites
Earliest fossils from 3.5 bya
56
Phanerozoic eon
Last 550 million yrs - most fossil record comes from this eon.
57
Paleozoic era
550-250 may "ancient life"
Example: Biggest mass die off at brink at Premian/Triassic boundry. >50% of families and >80-90% species (due to vulcanism.
58
Mesozoic era
250-65 may "middle life"
59
Cenozoic era
65 may - present "recent life"
| Example: Another big extinction at cretaceous/tertiary boundry. Dinosaurs, ammonites and rudists decimated.
60
Mass extinction
99% of all species are extinct.
61
Proof of asteroid
High concentration of iridium, shocked quartz and Chicxulub crater.
62
Whale evolution
Ambulocetus, rodhocetus and modern whale
63
Transitional species
Only identified retrospectively.
| Example: Sphecomyrma freyi (ant/wasp), Archaeopteryx (dinosaur/bird)
64
Evolution mammals
Synapsid, therapsid, cynodont, mammals.
| Example: Morganucadon, hadrocodium wui (had a derived ear structure)
65
Developmental biology
Reconstructy paths of change to help us understand how genetic change impacts phenotype
*tells us about homologous characteristics.
Example: Stylopod, zeugopod, autopod (Tiktaalik had neck and limb bones, Acanthostega actual tetrapod limb skeleton).
66
Heterochrony
Evolutionary change in the timing or rate of development.
67
Paedomorphosis
Retain more juvenille features.
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Peramorphosis
Have more adult features.
69
Directional Selection
Example: Guppie size in streams with or without predators, beak size of Soapberry bug in Flordia.https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=0CAcQjRw&url=http%3A%2F%2Fwww.enotes.com%2Fhomework-help%2Fcompare-contrast-directional-selection-disruptive-469344&ei=DaI9VZCcPMa3ogS49YHYBg&bvm=bv.91665533,d.cGU&psig=AFQjCNHE0RjMsQJimOntbQOuw7CLXL0uHQ&ust=1430188892248631
70
Paedomorphosis
Retention of a juvenile characteristic as a sexually mature adult.
Example: 1. Axolotl
2. Human skull shape
compared to apes
71
Peramorphosis
Extended fetal growth rate because of delayed maturation.
| Example: Human brain/body size ratio.
72
Atavisms
Traits reappearing that have disappeared generations before (i.e. throwbacks to ancestral form).
Example: Horses with side toes, whales with femurs, chickens with teeth, humans with tails.
73
Pseudogenes
Organisms retain genes for making structures no longer found in their lineage.
74
Primates
1. Mammal order, 250 sp.
2. Chacteristics: (1) stereoscopic
color vision, (2) large brain/body size, (3) tree-dwelling tropical creatures.
3. Adaptations: (1) opposable thumb, (2) flat nails, (3) complex facial muscles, (4) free rotation at shoulder, (5) half rotation at elbow.
75
Strepsirhines
Wet-nosed primates.
| Example: Lorises, galagos, lemurs.
76
Haplorhines
Dry-nosed primates.
77
Tarsliformes
Tarsiers
78
Anthropoldea
(simiiformes)
79
Platyrhines
New-world monkeys, prehensile tail.
| Example: spider monkey.
80
Catarrhines
No prehensile tail, 2 premolars, narrow nose, TRICHROMATIC color vision (can tell red-green).
Example: Baboon, proboscis monkey.
81
Cercopithecoids
Old-world monkeys.
| Example: gibbons
82
Hominoids
Apes (and humans)
Characteristics: erect posture, spine stiffer, arms flexible, larger pelvis, NO tail.
Example: Oranguatn, gorilla, both chimp species and humans.
83
Orangutan
Fruit eaters, habitual brachiation.
| Example: Bomean, Sumatran
84
Gorilla
Dominated by males, live in polygynous colonies (males 2x size of females).
85
Chimpanzee
Extended childcare, sleep in trees, knuckle-walker, extensive tool use.
Example: Bonobo, Chimpanzee. Split from humans 7 million yrs. ago.
86
Anatomically Modern Humans (AMH)
We can trace linage of AMH via fossil record in the rift valley. First seen 100,00 ya.
87
Ardipithecus ramidus
Live 4.5 mya. Had:
1. Small brain
2. Bipedal
3. Ape like
88
Australopithecus afarensis
```
Lived 3 mya. Had:
1. Small brain
2. Bipedal
3. Strong ape jaw
Example: Lucy
```
89
Australopithecus africanus
Lived 2.5 mya. Had:
1. Slightly larger brain
Example: Taung child
90
Australopithecus garhi
Lived 2.5 mya. Contemporary to A. africanus.
91
Australopithecus sediba
Lived 2 mya. More like homo than other australopithecines.
92
Paranthropus robustus/boisei/aethiopicus
Lived 2.5 mya. Had:
1. Small brain
2. Strong eyebrow line (sagittal crest)
3. Big jaw
93
Homo
1. Increased brain/body size ration
| 2. Made stone tools
94
Paleolithic tools
H. habilis made OLDOWAN tools, H. erectus made ACHEULEAN,
H. neanderthalensis made MOUSTERIAN,
H. sapiens made AURIGNACIAN
95
Paleolithic tools
H. habilis made OLDOWAN tools, H. erectus made ACHEULEAN,
H. neanderthalensis made MOUSTERIAN,
H. sapiens made AURIGNACIAN
96
H. ergaster
Lived 1.5 mya. Had:
1. Bigger brain
2. Not human/not ape
Example: Turkana boy
97
H. erectus
```
Lived 1.7 mya. Had:
1. Bigger brain
2. Not totally human yet
Shows pre-humans moving out of Africa
Example: Skeleton in Republic of Georgia,
Java Man (Beijing man lived .75 mya).
```
98
H. Neanderthals
Lived until 30,000 ya. Had:
1. Strong brow line
2. Big Nose
3. Stocky body build
4. Sloping forehead
5. Occipital bun
99
Multiregional model
H. erectus/sapiens spread around old world and simultaneously evolved to modern form through GENE FLOW
100
Replacement model (out-of-Africa model)
Single group of H. sapiens dispersed from Africa and killed off/replaced all other pre-AMH species.
101
Stone-Age genomics
1. We have average similarity in DNA of 99.5%
2. Europeans/Asians show 2-8% Neanderthal DNA
3. Some gene flow between AMH and Neanderthals abt 50 – 60, 000 ya
4. Entire mtDNA genome points to African origins
102
Cro-Magnon people
1. First seen 35-40,000 ya.
2. Made fires, buried people, had
religion by 28,000 ya.
3. Made beads 80,000 ya
4. Minor genetic change as we
spread (i.e. cold tolerance, malaria resistance, skin color, height, etc.)
5. Gradual transition to H. sapien during Pleistocene
103
Ecology
Study of interactions between organisms and their environments.
104
Abiotic components
Light, water, temp, wind
105
Biotic components
Organisms ( i.e. predator, prey, parasites, etc)
106
Density
number of individuals per unit area.
107
Dispersion
Clumped, uniform, random
108
Vital statistics
Tell us if our population is growing, shrinking or staying the same. Need to know: (1) age structure, (2) birth rate and (3) death rates which allow you to calculate (4) generation time.
109
Generation time
Average time between the birth of a female and the birth of her offspring.
110
Net replacement rate
The net replacement rate = the sum of Ix times mx for each age class. x:
Be able to calculate net replacement rates and decide whether a population is growing or shrinking from a life table.
111
Survivorship curves
Be able to identify the three different types.
112
Life-history traits
Traits that effect births and deaths.
| Example: life-span, age of first reproduction, litter size, number of times organism reproduces.
113
Semelparity
Reproduces once and a whole bunch all at once (big-bang reproduction).
Example: Salmon, century plant
114
Iteroparity
Repeated reproduction
| Example: Oak trees, humans
115
Trade-off between current reproduction and survival
The less babies you make (or no babies) the more likely you are to survive. When you invest engergy and resources into reproduction you are more likely to get eaten by a predator/starve etc
116
Logistic growth model
dN/dt = rN (K - N / K)
dN/dt =Change in population size over a
change in time
=rate of population change (births minus deaths)
=the number of individuals in the
= carrying capacity (maximum population size that can be supported by availabe resources
Example: If dN/dt is negative the population will be decreasing. If dN/dt is positive it will be increasing.
117
Positively density-dependent factors
A regulating mortatlity factor has positively density-dependent factors. The bigger the population size, proportionally more individuals will be killed.
**Keeps populations within upper and lower bounds
Example: Food and water, predation, vector-transmitted diseases, territorial behavior, toxic wastes. Ex. Reproduction of sheep.
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Human population growth
Humans grow exponentially because of a drop in death rates.
119
Ecological community
Assemblage of species in a given area.
120
Interspecific interactions
Interactions between two species.
| Example: Competition, consumer-victim, mutualism, etc.
121
Competition
↓Species 1 ↓Species 2
| Example: Competitive exclusion, fundamental/realized niche, character displacement.
122
Consumer-victim
↑Species 1 ↓Species 2
| Example: Predation, Herbivory, Parasitism Cryptic/Aposematic Coloration, Batesian Mimicry, Secondary compounds
123
Mutualism
↑Species 1 ↑Species 2
Example: Pollination, ants tend aphids/treehopper—they get food and treehooper gets protection, ants and the acacia tree, impala and oxpecker.
124
Commensalism
↑Species 1 0 Species 2
| Example: Egrets and large ungulates.
125
Amensalism
↓Species 1 0 Species 2
| Example: Gypsy moth
126
Population cycles
Density-dependent predation can lead to population cycles.
| Example: snowshoe and lynx
127
Prey defenses
Help prey escape their predators.
Example: Cryptic coloration, mimicry, etc
**Can have a combination of morphological/behavioral defense (like KILLDEAR which has cryptic colored eggs and fakes a broken wing to attract attention away from its nest.).
128
Cryptic coloration
Prey blends in with environment.
| Example: Catepillar that looks like bird dropping or a leaf, tawny frogmouth.
129
Aposematic coloration
Distasteful or dangerous (poisonous) prey use bright coloration to warn off predators.
Example: Poison-dart frogs, fire salamander, monarch butterfly.
130
Batesian mimicry
Harmless prey mimics a dangerous one.
| Example: Flies look like honeybees.
131
Batesian mimicry
Harmless prey mimics a dangerous one.
| Example: Flies look like honeybees, yellow jackets, etc.
132
Counter-strategy
Predator evolves a behavior in order to overcome prey defense, or herbivore will overcome plant defense.
Example: Mouse sticks stink bug hind end in soil and eats it. Katydid cuts where resin oozes and then katydid eats top of plant.
Tobacoo hornworm have enyzme that converts nicotine to nornicotine which is nontoxic.
133
Physical defenses in plants
Thorns, spines, leaf toughness.
134
Secondary compounds
Part of plants chemical defense, are biproducts of biochemical pathways and plant will keep them to make them distasteful or poisonous. Have three different uses (1)deter feeding, (2) interfer with digestion or (3) act as toxin.
Example: Alkoliods (in potato, tomato, tobacoo) –nicotine toxic to human and insects, caffine, capsasin
Rotenone, angelicin, mescaline.
135
Constitutive toxins
Always present in high levels in plants
136
Induced toxins
When plant is wounded/or infect by bacteria, the plant will increase the amount of toxin in the plant.
137
Competitive exclusion
**Intensity of competition depends on the organisms ecological niches.
138
Niche
Sum total of the organisms use of biotic and abiotic resources.
Example: Habitat = address. Niche = occupation
139
Fundamental niche
Set of environmental condition and resources within which the population can sustain positive growth.
140
Realized niche
(must be smaller or equal to fundamental niche) the space the organism actually occupies.
Examples: Chthamalus, Balanus
141
Character displacement
If competition is strong enough for long enough, the will adapt to minimize the competition.
Example: Darwin's finches
142
Keystone species
If you remove the species then the species diversity will go down.
Example: Pisaster sea star (if gone then you get bivalve muscle bed that out compete everything)
143
Biodiversity
Genetic diversity, species diversity in ecosystem, community and ecosystem diversity in region.
Example: Abt 2 million species w/latin name on earth
**but we don’t have a good estimate.
144
Species-area relationships
If you plot log number of species against the log number of area you get a linear relationship. Can help you get a good idea of what extinction rate is from this.
145
Extinction
Causes: habitat destruction (brazil), introduction of exotic organisms/diseases (argentine ant), pollution, over harvesting.
Example: Passenger pigeon (hunted out by 1914), Great auk (hunted to extinction),
146
Fragmented habitats
Does not support as large a diversity of animals
147
Endemic species
Found only in a small specific region.
Example: Species in Hawaii, many bird species in Hawaii are dying off because of introduction of forgein species (malaria, predation.
148
Background rate of extinction
Rate of extinction before human activities.
| Example: **human extinction rate is 10 -100 times faster than the background rate.
149
Extinction (Why worry?)
```
1. Recovery time much longer than
human time (million of yrs)
2. We’re present this time
3. We’re losing organisms we
could use as resources
4. We need organisms to maintain
ecosystem health
Example: Rosy Periwinkle (helped treat Hodgkin’s disease and childhood leukemia.
```
150
Behavior
What an animal does and how and why it does it.
| Example: Proximate vs ultimate (black headed gull moving egg shells—deflects predation).
151
Partial genetic basis
Behaviors can be modified by natural selection.
Example: Fischer’s lovebird vs peach- faced lovebird, maedow voles vs prairie voles, blackheaded gull vs kittiwake gull (ULTIMATE CUES).
152
Proximate cues for behavior
Example: 1. Bee-wolf (Have spatital learning by flying around in circle around nest and remembering visual landmark)
2. Male singing bird:
comes from hormones (melationin: seasonal timing, estrogen: primes song system, testosterone: activates song)
153
Fixed-action pattern
Innately programmed behavior triggered by a single stimulus (sign stimulut/release).
Example: Sticklebacks (respond to red on objects), Greylag goose (moves round object into nest).
154
Learning
Allows an individual to adjust its behavior in an adaptive way.
Example: Habituation, imprinting, associate learning, cognition, play
155
Habituation ("cry-wolf" effect)
When an animal learns not to respond to a stimulus
156
Imprinting
Irreversible and occurs only during critical window of time.
| Example: Goslings follow any large object=”mom”.
157
Classical conditioning
Animal associates a neutral stimulus with a non-neutral stimulus. Animal pairs stimuli in an adaptive way. Reservable.
Example: 1. Pavlov dogs.
NEUTRAL STIMULUS = bell. NONNEUTRAL STIMULUS= meat.
2. Fruit flies avoid odor that is associated with electric shock.
158
Operant conditioning
Animal learns to associate on of its own behaviors with an outcome (trial-and- error learning).
Example: Skinner box (one bar presses gives mouse food).
159
Animal cognition
Complex form of learning that involves reasoning, problem-solving, judgment.
Example: Predator-specific alarms, chimps crack nuts, chimps stack boxes.
160
Animals sense world different than us
1. Communication for many organisms mediated by pheromones
2. bees guided by UV light
3. bees dance to communicate
161
Pheromone
Chemical released by animals that communicate something.
162
Round dance
Bee saying food is nearby.
163
Waggle dance
Food is further away. Make figure 8 in vertical portion of hive. Angle of waggle dance is proportional to direction you have to fly from where sun is now.
Example: Up = towards sun. Down = away from sun
164
Altruistic
Decrease the fitness of individual expressing the behavior but benefits other individuals
**happends in organisms with stable kin groups.
Example: Alarm-calling ground squirrels.
165
Altruistic
Decrease the fitness of individual expressing the behavior but benefits other individuals
**happends in organisms with stable kin groups.
Example: Alarm-calling ground squirrels.
166
Kin selection
Special kind of natural selection where genes will spread if it benefits enough close relatives.
167
Non-zero heritability
All behaviors have a partial genetic basis
168
Heritability
Proportion of total phenotypic variability caused by underlying genetic
variation
h^2 = Vg/Vp
Ranges from 0 -1
0.5 variation means that half variation due to genes half due to environment.
Example: Have found 75 genes that increase risk to schizophrenia. Some alleles help you be smart for other genetic backgrounds non-adaptive. Monoamine oxidase gene, dopamine D2 receptor gene (learn from mistakes), FOXP2 transcription-factor for language development
