Lesson5&6

Question 1

Natural selection; short version

Answer 1

1) Individual heritable variation
2) limited resources+exponential population growth= competition
3) competition= unequal(differential) survival and reproduction among individuals
4) heritable tait that enhance competitive ability, or fitness and reproduction) of individuals in the local environment are passed to offspring and preserved in the population
5) Natural selection is nonrandom and predictable on short time- scales
Natural selection- evolution of adaptations.

Question 2

The trait must be variable

Answer 2

• height varies among individuals in a population

Question 3

The trait must affect fitness

Answer 3

• taller individuals have a higher chance of surviving to reproductive age, finding mates, and producing offspring than shorter individuals

Question 4

The trait must be heritable

Answer 4

• offspring resemble parents: tall parents produce, on average, tall offspring, and short parents produce, on average, short offspring; height has a genetic basis

Question 5

” In every generation more individuals are born than can possibly survive”

Answer 5

Lamarck

Question 6

artificial selection may give rise to maladaptive traits

Answer 6

False

Question 7

Natural selection= survival of the fittest

Answer 7

False- you don’t have to be finest to survive

Question 8

A population od clonal(genetically and phenotypically identical) organism can evolve by—— selection?

Answer 8

None- there is not selection- violates selection

Question 9

Charles Darwin believed that traits are passed down from parents to offspring through a process called

Answer 9

• condominance

Question 10

Consider a very large population of insects. Larger individuals have more offspring than smaller individuals, body size is heritable, and the average body size in the population increases 1.5x in 50 generations. This is an example of evolution by
1)disruptive selection
2)stabilizing selection
3) genetic drift
4)directional selection
5) any of the above

Answer 10

Any of the above

Question 11

Selection in Galapagos Finches
Basic Facts about Medium Ground Finch (Geospiza fortis) on Daphne major

Answer 11

1) Small island, small population of birds(1,200) can mark and measure every individual every year; know parent and offspring of every individual
2) Tropical island(always warm) but with wet and dry season; most rain in wet season
3) Birds eat seeds; pick up and crack open
4) Birds with bigger beaks can crack open bigger seeds
5) Natural selection on beak size caused by drought in 1977

Question 12

Natural selection 4 basic ideas(principles)

Answer 12

1) individuals within a population vary in a trait
2) variation passed onto offspring(heritable)
3) individuals vary in survival
4) Survival non-random, individuals with favorable traits pass on more offspring to next generation

Question 14

Mutation produces——- heritable phenotypic variation

Answer 14

random

Question 15

Natural selection sorts existing variation….

Answer 15

non-randomly

Question 16

Evolution by natural selection

Answer 16

• Random generative process
• Mutation produces random heritable phenotypic variation
• nonrandom sorting process
• effects on evolution maybe be predictable on short time-scales
• differential survival and reproduction based on fitness- associated phenotypic variation
• natural selection is typically the dominant engine of evolution(except in small populations)

Question 17

Evolution by genetic drift

Answer 17

• Random generative process
• mutation produces random heritable phenotypic variation
• random sorting process
• genetic drift sorts existing variation randomly
• effects on evolution not predictable
• diferential survival and reproduction based on chance
• genetic drift is important in small populations

Question 18

Genetic drift may play an important role in evolution

Answer 18

after a bottlenecking event.