1&2:Adapation and Speciation

Question 1

Natural Selection

Answer 1

non random process by which biological traits become more or less common in a population. Key mechanism of evolution.

Question 2

Natural Selection will occur when

Answer 2

individuals are variable in some traits, at least some of this variation is heritable, individuals with some trait values survive or reproduce better than others.

Question 3

Darwin’s major insight

Answer 3

that heritable variation can, under the right conditions, lead to speciation.

Question 4

Alfred Russel Wallace

Answer 4

developed the theory of natural selection at the same time as Darwin, joint manuscript with Darwin.

Question 5

Galapagos Islands

Answer 5

characteristics introduce different selective pressures to organisms in the islands.

Question 6

Galapagos Finches

Answer 6

differently shaped bulls as result of natural selection

Question 7

Selection differential

Answer 7

the mean value of a trait after selection minus the mean value of that trait before selection.

Question 8

response to selection

Answer 8

mean value of a trait in the next generation minus the mean value of that trait before selection.

Question 9

Fitness

Answer 9

The ability for an organism to pass its genes on to the next generation.

Question 10

What are the types of selection

Answer 10

directional, stabilizing or purifying, and disruptive

Question 11

Directional

Answer 11

favors phenotypes at one end of a distribution. The population evolves in that direction.
Mean phenotype: increases or decreases depending on what is selected for
Variance in phenotype: not necessarily changed

Question 12

Stabilizing

Answer 12

selection favors values towards the middle of the distribution.
Mean of phenotype: does not change
Variance: decreases because the phenotypes at either end of the distribution have been selected against.

Question 13

Disruptice

Answer 13

favors phenotypes towards the ends of the distribution (farther form the mean)
Mean phenotype: no change as long as individuals on both ends of the distribution have equal fitness
Variance of phenotypes increases.

Question 14

Frequency dependent selection

Answer 14

occurs when the fitness of a genotype depends on its frequency in the population

Question 15

Negative frequency dependent selection

Answer 15

a phenotype has the greatest selective advantage if its is rare.

Question 16

Positive frequency dependent selection

Answer 16

a phenotype has the greatest selective advantage if it is common.

Question 17

Direct Fitness

Answer 17

contribution that an individual makes to the gene pool through their own offspring

Question 18

Indirect Fitness

Answer 18

comes from an individuals genes being represented in the gene pool of subsequent generations because their relatives, with whom they share alleles, successfully reared offspring

Question 19

Direct Fitness Part 2

Answer 19

determined by the number of offspring an organism produces over its entire lifetime.

Question 20

Life History

Answer 20

timing and the duration of key events during a life time (age, duration of reproduction, number and size of offspring produced) that can influence an organisms fitness

Question 21

Life History Trade Offs

Answer 21

1. Current reproductive success
2. Future reproductive success
3. Likelihood of surviving

Question 22

Formula to find offspring each year

Answer 22

Max number of os

Question 23

Survival vs Reproduction

Answer 23

one strategy: High survival, delayed reproduction.

Question 24

Guppes of Northern Trinidad

Answer 24

Above Waterfalls: low predation, high sruvivial
Below waterwalls:
high predation, low survivial

Question 25

Extrinsic Mortality

Answer 25

rate at which eternal events (predation, starvation, infectious disease) leads to death in a population

Question 26

Intrinsic Mortality

Answer 26

rate at which internal events (aging, disease, mutations), lead to death in a population.

Question 27

Senescence

Answer 27

decline with age in per capita reproductive performance , physiological function or the probability of survival

Question 28

Antagonistic Pleiotropy

Answer 28

allele can be favored because it benefits early life survival or reproduction even if it has very determinital effects later in life.

Question 29

Individual Selection

Answer 29

differential performance of individuals causes some genotypes to replace other genotypes.

Question 30

Group Selection

Answer 30

differential performance of groups of individuals causes some groups to out compete and replace others. But selection can favor cheater phenotypes within groups, undermining group selection for altruism.

Question 31

True Altriusm

Answer 31

reduces inclusive fitness. rare, because it is evolutionarily disadvantageous