Chpt 22: Evolution By natural selection

Question 1

Evolution

Answer 1

what happens when there is a change in allele frequency from generation to generation

Question 2

Sexual dimorphism

Answer 2

any trait that differs between males and females

Question 3

Pattern

Answer 3

1 of 2 mechanisms of intersexual selection

when traits that attract members of the opposite sex are much more highly elaborated in males.

Question 4

Differential Reproduction

Answer 4

when individuals with favorable traits can/reproduce more

Question 5

Non-Adaptive Evolution

Answer 5

random/unpredictable

involves gene flow, genetic drift, and mutation

Question 6

Heritability formula 
(with selection diff and response to selection diff)

Answer 6

h^2 = R/S

where R is delta mean response to selection
and
S is delta mean selection differential

Question 7

Frequency

Answer 7

part of a whole; percent

exp. allele frequency for rr is 25%

Question 8

Viability

Answer 8

Likelihood that an individual bearing a genotype will survive

Question 9

Cutoff of saying a heritability score means evolution by natural selection has occurred

Answer 9

0.2 or bigger

Question 10

Intersexual selection

Answer 10

1 of 2 types of sexual selection

when an individual is chosen by the opposite sex (i.e. penguins mate selection up to the female)

Question 11

Fecundity

Answer 11

Number of gametes per individual

Question 12

Selection differential formula

Answer 12

S = P* - Pbarr basically trait final - trait initial

where P* is trait frequency after event and Pbarr is the trait frequency before the event

Question 13

Differential Survival

Answer 13

when individuals with favorable traits can/survive more

Question 14

Mating success

Answer 14

Defined by number and quality of mates

Question 15

Heritability (formula)

Answer 15

H^2 = Vgenetic/(Vgenetic + Venvironmental)
or
H^2 - Vgenetic/Vpopluation

Question 16

Fitness

Answer 16

defined by the average reproductive output (Rbarr) of all individuals bearing a given genotype

rate at which certain alleles make it into the next generation

certain alleles can confer greater fitness

Question 17

Fertilization success

Answer 17

Defined by number of

Question 18

Environmental/Ecological Selection

Answer 18

favors traits that increase success in surviving in/adapting to the environment,

Question 19

Relative Fitness

how to calculate it

Answer 19

Rbarr / Fitest genotype’s Rbarr

exp, mommy’s Rbarr / daddy’s Rbarr = 0.5

Question 20

Cross foster/Common Garden Experiments

Answer 20

When you can orgs. out of one pop and drop them into another one (to determine if their phenotypes are genetic or environmental)

Question 21

Adaptive Evolution

Answer 21

Non-random/predictable

involves natural selection

Question 22

Sexual selection

Answer 22

(natural) selection based on success in courtship

Favors traits that increase success in mating (rather than ones that increase success in adapting to the environment)

Question 23

Selection differential

Answer 23

Quantification of a trait before and after a selection event

e.g. delta mean beak size or beak size final - beak size initial

Question 24

Fundamental asymmetry of sex

Answer 24

the idea that females’ fitness is low bc she spends a ton of energy taking care of whatever babies she already has

AND

the males fitness is high bc they don’t contribute much work raising the babies and are thus free to make tons of babies.

Question 25

Population

Answer 25

A group of orgs of the same species living in the same area that can interbreed with one another

Question 26

4 pillars of natural selection

Answer 26

reproduction
heredity
variation in individuals
variation in fitness

Question 27

Homologous Traits

Answer 27

traits (like bones and wings) that are derived from a common ancestor.

Question 28

INTRAsexual selection

Answer 28

1 of 2 types of sexual selection

when individuals compete with other members of the same sex in order to be chosen by the opposite sex

Question 29

Process

Answer 29

1 of 2 mechanisms of intersexual selection

when females in most species invest much more in their offspring than do males (bc it is a bigger energy investment for them).

Question 30

Fertilization success????

Answer 30

Defined by number of

Question 31

Inbreeding

Answer 31

mating between relatives

Question 32

Territory

Answer 32

Part of males’ antics in INTRAsexual selection

Involves an area that is actively defended and that provides exclusive or semi-exclusive use by the (male) owner.

Question 33

Heritability

Answer 33

the proportion of phenotypic variation that is caused by genetics/genotype variation

Question 34

Selective pressure

Answer 34

any factor that reduces reproductive success in a portion of a population

exp. predators, outbreaks, limited resources