DAT bio chapter 13 evolution

Question 1

Evolution is the gradual development and
change of ______ (allele frequencies) in
populations over successive generations.
Evolution increases ______

Answer 1

heritable traits

biodiversity.

Question 2

What is embyrology

Answer 2

embryological
similarities and differences between early
stages of related organisms. Eg. all chordates
have a gill slit during development.

Question 3

what is comparative anatomy

Answer 3

compares different

body parts of different animals:

Question 4

Homologous structures:

Answer 4

may or may not
perform the same function but have a
common ancestor. eg. forearm of bird and
forearm of human.

Question 5

Analogous structures:

Answer 5

same function, do
not have a common ancestor. eg. bird
wings and bat wings.

Question 6

Vestigial structures:

Answer 6

serve no purpose
but are homologous to functional
structures in other organisms eg. human
appendix and cow cecum.

Question 7

Biochemical methods allow for waht

Answer 7

DNA
sequence comparisons.
Can see conserved
DNA sequences (higher similarity = higher
relatedness) and common conserved
pathways (eg. Krebs cycle).

Question 8

Who proposed catastrophism?

Answer 8

Cuvier

Question 9

What is catastrophism

Answer 9

mass extinctions of species in areas. different
populations in different areas were shaped
by what catastrophes had occurred, and
what random organisms then survived and
populated that area.

Question 10

Who proposed use and disuse and inheritance of acquired traits

Answer 10

lamark

Question 11

What is use and disuse?

Answer 11

used body parts will
develop and unused ones are weakened,
leading to evolution.

Question 12

what is Inheritance of acquired traits:

Answer 12

traits
acquired through use and disuse are
passed onto offspring (eg. giraffe
stretching neck will cause its neck to
develop, and produce long necked
offspring). This is incorrect - acquired
characteristics are generally not heritable.

Question 13

What is natural selection?

Answer 13

gradual, non-random
process where allele frequencies change as a
result of environmental interaction.

Question 14

What is survival of the fittest?

Answer 14

fittest occurs as individuals with greatest
fitness (ability to survive and produce viable
and fertile offspring) have greatest success, and
pass on more DNA to future generations
compared to less fit parents.
parents. Leads to the
evolution of the population (not individuals).

Question 15

requirements for natural selection 1

Answer 15

Demand for resources exceeds supply:
results in competition for survival (fittest
survive to pass on genes).

Question 16

requirements for natural selection 2

Answer 16

Difference in levels of fitness due to variation
in traits: differentiate ability to compete and
survive (eg. black peppered moths favored
over white moths during Industrial
Revolution).

Question 17

requirements for natural selection 3

Answer 17

Variation in traits must be genetically-influenced (heritable) to be passed onto

offspring.

Question 18

requirements for natural selection 4

Answer 18

Variation in traits must be significant for
reproduction and/or survival: genes
improving reproductive success/survival are
favored and increase over generations and
vice versa.

Question 19

3 types of natural selection

Answer 19

stabilizing selection
directional selectin
disruptive selection

Question 20

Stabilizing Selection:

Answer 20

mainstream (average)
is favored (eg. birth weight). Diagram follows
a standard bell curve.

Question 21

directional selectin

Answer 21

one extreme favored
(eg. longest giraffe neck allows access to the
most leaves).

Question 22

disruptive selection

Answer 22

Selection: rare traits favored,
mainstream is not. (eg. snails living in low
and high vegetation areas).

Question 23

Sexual Selection:

Answer 23

non-random mating between
males and females. Females favor high quality
partners, males prefer high quantity of partners
to increase their number of offspring.
Note: traits selected for may be favorable for
reproduction but not for survival.

Question 24

Artificial Selection:

Answer 24

carried out by humans to
selectively breed for specific traits (eg. dog
breeding).

Question 25

What does hardy weinbery formula calculate?

Answer 25

``` calculates genetic frequency during genetic equilibrium (no change in gene frequencies). If both equations hold true, the population is under Hardy-Weinberg equilibrium. ```

Question 26

Mnemonic for the requirements for hardy weinberg equilibrium

Answer 26

(Mnemonic: Large, Random, M&M) ● Large population: minimizes genetic drift. ● Random mating ● No mutation ● No natural selection ● No migration (gene flow): population must be isolated. When conditions are not met, evolution occurs.

Question 27

What is microevolution?

Answer 27

process when gene frequencies change within a population over generations (favorable genes increase, unfavorable decrease).

Question 28

Factors Causing Microevolution

Answer 28

1. Genetic Drift: allele frequencies change by chance. Larger effects on small populations. ● Bottleneck effect: smaller gene pool, some alleles may be lost (eg. disaster killing majority of population). ● Founder effect: some individuals migrate away from the population. 2. Non-random Mating: sexual selection, outbreeding, inbreeding. 3. Mutations: can be dormant until environmental change allows it to flourish. 4. Natural Selection: no luck involved 5. Gene Flow: migration (non-random) moving alleles between populations, leading to variation through mixing.

Question 29

Sources of genetic variation

Answer 29

1. Mutation: must not be fatal. 2. Sexual Reproduction: crossing over, independent assortment and random joining of gametes. 3. Balanced Polymorphism: maintains a variety of phenotypes within a population. ● Heterozygote advantage (eg. sickle Cell Anemia). ● Minority Advantage: rare phenotypes offer higher fitness. Cycle between high and low frequency. (eg. advantageous against hunters’ search images). ● Hybrid Advantage: Two strains of organisms produce more superior offspring. ● Neutral Variations: may become beneficial if the environment changes. 4. Polyploidy: plants have multiple copies of alleles introducing more variety and preserving different alleles. Can also mask effects of a harmful recessive allele.

Question 30

What is macroevolution?

Answer 30

is long-term and occurs at a level at or higher than species. Species are reproductively isolated (via prezygotic and postzygotic isolating mechanisms) resulting in a lack of gene flow between species.

Question 31

Prezygotic isolation (macroevolution)

Answer 31

prevents fertilization | from occuring between species.

Question 32

Types of prezygotic isolation

Answer 32

``` Habitat Isolation: occupying different habitats. ● Temporal Isolation: reproducing at different times/seasons. ● Behavioral Isolation: different courtship rituals. ● Mechanical Isolation: male and female genitalia are not compatible. ● Gamete Isolation: gametes do not recognize / fertilize each other (eg. zona pellucida on mammalian oocytes). ```

Question 33

Postzygotic Isolation: (macroevolution

Answer 33

Isolation: backup in case hybrid | zygote forms.

Question 34

Types of postzygotic isolation

Answer 34

``` ● Hybrid Mortality: hybrid zygote not-viable (often due to different chromosome numbers). ● Hybrid Sterility: hybrid zygote sterile. ● Hybrid F2 Breakdown: offspring of hybrids have decreased fitness. ```

Question 35

Speciation is how species form, starting with ________, which leads to interruption of _____between populations that gradually develop into _______

Answer 35

reproductive isolation gene flow two species.

Question 36

Allopatric Speciation: happens when

Answer 36

occurs due to a | geographical barrier.

Question 37

Type of allopatric speciation

Answer 37

``` Adaptive Radiation: occurs when many species arise from one ancestor as they adapt differently to their environments. During adaptive radiation, species can specialize to fill different niches within the same environment. ```

Question 38

Sympatric Speciation: happens when

Answer 38

occurs without a | geographical barrier.

Question 39

Types of sympatric speciation

Answer 39

``` ● Balanced Polymorphism: different phenotypes are isolated within the same area. ● Polyploidy: in plants results from nondisjunction during meiosis. (eg. Two 3n organisms - usually sterile - meet and are reproductively compatible). ● Hybridization: some hybrids are more fit than purebreds. ```

Question 40

What is phyletic gradualism (theories of macroevolution)

Answer 40

evolution happened gradually via accumulation of small intermediary changes. Not likely to be true (not supported by fossil evidence).

Question 41

What is punctuated equilibrium? (theories of macroevolution)

Answer 41

short spurts of evolutionary changes during periods of stasis (supported by fossil evidence).

Question 42

What is divergent evolution?

Answer 42

species diverge from | common ancestor.

Question 43

What is Convergent Evolution (Homoplasy):

Answer 43

unrelated species adapt to similar environments becoming more alike (analogous structures).

Question 44

What is parallel evolution?

Answer 44

species diverge from a common ancestor but undergo similar changes.

Question 45

What is coevolution?

Answer 45

two species impart selective | pressure on each other.

Question 46

Types of coevolution?

Answer 46

``` ● Camouflage (cryptic coloration): match appearance to environment to avoid detection. ● Aposematic Coloration (warning coloration): vibrant coloration in poisonous animals to warn predators. ● Mimicry: evolving to resemble another species. In Batesian mimicry a non-harmful animal resembles a harmful one. In Mullerian mimicry, two poisonous animals resemble each other to warn their predator. ```

Question 47

What is a phylogenetic tree?

Answer 47

branched diagram that shows inferred evolutionary relationships between different taxa. A clade is a cluster with an ancestor and all its descendants.

Question 48

What is Cladogenesis

Answer 48

``` refers to the splitting apart of evolutionary lineages (formation of new clades). ```

Question 49

What is anagenesis?

Answer 49

describes the gradual evolution of | an interbreeding population without splitting.

Question 50

What is parsimony?

Answer 50

means the simpler the evolutionary explanation, the better. Phylogenetic trees minimizing evolutionary reversals, convergent evolution and parallel evolution are preferred.

Question 51

Big bang timeline

Answer 51

14 billion

Question 52

earth is how old

Answer 52

4.5 billion

Question 53

prokaryotes are how old

Answer 53

3.5 billion

Question 54

eukaryotes are how old

Answer 54

2 billion

Question 55

earths current atmosphere has how much nitrogen oxygen and argon

Answer 55

● Nitrogen gas (most common) = 78%. ● Oxygen gas = 21%. ● Argon gas = 0.9%. ● Trace amounts of CO2 , methane, ozone.

Question 56

Primordial earth p1 Earth’s primordial atmosphere consisted of _____ and ______ - it was a reducing environment.

Answer 56

inorganic compounds | no oxygen

Question 57

Primordial earth p2 Earth cooled down, gases condensed to form the _____

Answer 57

primordial sea

Question 58

Primordial earth p3 Simple compounds became more _____, organic compounds ____

Answer 58

complex | formed.

Question 59

Primordial earth p4 Organic monomers became _____ to form _____behave like proteins).

Answer 59

polymers | protenoids (

Question 60

Primordial earth p5 ______ arose: precursors to cells. Had microsomes (membrane-like) and proteinoids.

Answer 60

Protobionts

Question 61

Primordial earth p6-7 ``` Heterotrophic prokaryotes form. 7. Autotrophic prokaryotes form (eg. cyanobacteria - can photosynthesize). ● Important: The development of autotrophs led to the ______ and its accumulation (oxidizing environment forms). ```

Answer 61

production of | oxygen

Question 62

Primordial earth p 8 Oxygen accumulates, reacts with UV light to form _____, which blocks UV. This terminates _______.

Answer 62

ozone layer | abiotic chemical evolution

Question 63

Primordial earth p 9 ``` Primitive eukaryotes form ● _______ membrane-bound organelles (mitochondria, chloroplasts), once free-living, were phagocytosed by other prokaryotes and lived in symbiosis with them as organelles. ```

Answer 63

Endosymbiotic theory:

Question 64

Primordial earth p 9 More _____ eukaryotes and multicellular organisms begin to _____

Answer 64

complex | evolve.

Question 65

What is the organic soup theory

Answer 65

believed that oxygen in the primordial atmosphere must have been too reactive for organic chemicals to be produced, and therefore oxygen must have been lacking in the primordial atmosphere. Strong energy (eg. lightning, volcanic heat, UV radiation) drove reactions that formed organic compounds.

Question 66

Who proposed the organic soup theory

Answer 66

oparin and haldane

Question 67

what experiment mimicked the reducing environment proposed by opain and haldane?

Answer 67

Miller Urey experiment

Question 68

what was the miller urey experiment?

Answer 68

Set up a flask containing inorganic compounds and simple organic compounds but no oxygen (CH4 , NH3 , H2 , H2O) connected it to another flask with electrodes (simulates lightning) and heated it up (simulates high temperatures). Complex organic compounds (amino acids, organic acids, but no complete nucleic acids) were formed. Supports the Organic “Soup” Theory.