Evolution

Question 1

What is evolution?

Answer 1

Heritable change in a population over generations

Question 2

Microevolution vs. Macroevolution?

Answer 2

Micro = allele frequency changes; Macro = new species

Question 3

What is a population?

Answer 3

Interbreeding members of the same species in the same environment

Question 4

Key idea of natural selection?

Answer 4

Individuals with advantageous traits reproduce more

Question 5

What are the 3 requirements for natural selection

Answer 5

Variation, heritability, differential reproduction

Question 6

What is fitness?

Answer 6

Reproductive success

Question 7

Evidence of Evolution: What does the fossil record show?

Answer 7

Transitional forms

Question 8

Evidence of Evolution: Biogeography shows?

Answer 8

Species distribution patterns

Question 9

Evidence of Evolution: Homologous structures?

Answer 9

Same structure, different function

Question 10

Evidence of Evolution: Vestigial structures?

Answer 10

Reduced, nonfunctional remnants

Question 11

Evidence of Evolution: Convergent evolution

Answer 11

Similar traits evolve independently

Question 12

What are homologous genes?

Answer 12

Genes from a common ancestor

Question 13

Orthologs vs. paralogs?

Answer 13

Orthologs = different species; Paralogs = same species

Question 14

Horizontal gene transfer?

Answer 14

DNA exchange between species

Question 15

Gene pool?

Answer 15

All alleles in a population

Question 16

Allele frequency?

Answer 16

Proportion of a specific allele

Question 17

Genotype frequency?

Answer 17

Proportion of a genotype

Question 18

Hardy-Weinberg equilibrium equation

Answer 18

p^2 + 2pq + q^2 = 1

Question 19

Hardy-Weinberg: 5 conditions?

Answer 19

• No mutation - No new alleles introduced
• No natural selection - Equal survival and reproduction
• Large population - No genetic drift
• No migration - No gene flow
• Random mating - No mate preference

Question 20

Natural Selection Types: Directional selection?

Answer 20

Favors one extreme

Question 21

Natural Selection Types: Stabilizing selection?

Answer 21

Favors average

Question 22

Natural Selection Types: Disruptive selection?

Answer 22

Favors both extremes

Question 23

Natural Selection Types: Balancing selection?

Answer 23

Maintains diversity

Question 24

Genetic drift?

Answer 24

Random chance events are causing allele frequencies to fluctuate, typically in small populations.

Question 25

Bottleneck effect?

Answer 25

Sudden population reduction

Question 26

Founder effect?

Answer 26

A small group starts a new population

Question 27

Gene flow?

Answer 27

Movement of alleles between populations

Question 28

Inbreeding effect?

Answer 28

Increases homozygosity

Question 29

Speciation?

Answer 29

Formation of new species

Question 30

Allopatric speciation?

Answer 30

Geographic separation

Question 31

Sympatric speciation?

Answer 31

Same location, no barrier

Question 32

Reproductive Isolation: Prezygotic barriers?

Answer 32

Prevent mating/fertilization

Question 33

Reproductive Isolation: Prezygotic barrier examples?

Answer 33

Examples: Temporal Behavioral Mechanical

Question 34

Reproductive Isolation: Postzygotic barriers?

Answer 34

Offspring not viable or sterile

Question 35

Evolution Rate: Gradualism?

Answer 35

Slow, steady change

Question 36

Evolution Rate: Punctuated equilibrium?

Answer 36

Rapid bursts of change

Question 37

Lamarck

Answer 37

Proposed inheritance of acquired characteristics

Question 38

James Darwin

Answer 38

Proposed natural selection as mechanism of evolution

Question 39

Thomas Malthus

Answer 39

Populations grow faster than resources

Question 40

Hutton

Answer 40

Earth is very old (gradual change)

Question 41

Lyell

Answer 41

Uniformitarianism (same processes shape Earth over time)

Question 42

Adaptation

Answer 42

Trait that improves survival/reproduction

Question 43

Heritability

Answer 43

Traits passed from parent to offspring

Question 44

Variation

Answer 44

Differences among individuals

Question 45

Evidence of Evolution: Transitional fossils

Answer 45

Show intermediate characteristics

Question 46

Heterozygous (2pq)

Answer 46

One dominant, one recessive

Question 47

Homozygous recessive (q²)

Answer 47

Two recessive alleles

Question 48

Homozygous dominant (p²)

Answer 48

Two dominant alleles

Question 49

p + q = 1

Answer 49

Total allele frequency

Question 50

Hardy-Weinberg: q

Answer 50

Frequency of recessive allele

Question 51

Hardy-Weinberg equilibrium

Answer 51

No evolution; allele frequencies stay constant

Question 52

Hardy-Weinberg: p

Answer 52

Frequency of dominant allele

Question 53

Assortative mating

Answer 53

Similar individuals mate

Question 54

Fixation

Answer 54

Allele frequency reaches 100%

Question 55

Disassortative mating

Answer 55

Dissimilar individuals mate

Question 56

Inbreeding

Answer 56

Mating between relatives

Question 57

Intersexual selection

Answer 57

Mate choice (usually females)

Question 58

Adaptive radiation

Answer 58

One species diversifies rapidly

Question 59

Gametic isolation

Answer 59

Gametes cannot fuse

Question 60

Postzygotic barriers

Answer 60

After fertilization

Question 60

Hybrid inviability

Answer 60

Offspring does not develop

Question 61

Hybrid sterility

Answer 61

Offspring sterile (e.g., mule)

Question 62

Hybrid breakdown

Answer 62

Weak future generations

Question 63

Related but distinct calculations: Allele frequency

Answer 63

Number of copies of a specific allele in a population divided by the total number of all alleles for that gene in the population

Question 64

Related but distinct calculations: Genotype frequency

Answer 64

Number of individuals with a particular genotype in a population divided by Total number of individuals in a population