Selection- 3 Flashcards Preview

evolutionary biology of animals > Selection- 3 > Flashcards

Flashcards in Selection- 3 Deck (9)
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1

Constraints on what NS can do?

-Physical (physics)
-Pleiotropy (Gene influences multiple traits)
-Trade offs (trait has multiple functions)
-Linkage (Gene clusters)

-time frame
-past history
-No purpose to evolution (selection favours immediately beneficial changes)

2

What other processes other than NS can cause evolution?

-Genetic drift
-Sexual selection
-Artificial

3

Factors needed for NS?

-variation
-inheritance
-differential reproductive success
-(mutations)

4

Difference between absolute and relative fitness?

relative: the avg number of offspring 'relative to other individuals in the population'

5

Overdominance?

Over dominance is heterozygote advantage e.g. heterozygote for SCA
The heterozygote is higher in fitness than both homozygotes

6

What is frequency dependent selection?
Pos?
Neg?

The selective advantage of the trait depends on frequency of trit in the population.
fitness increase as trait frequency more common
fitness decrease as trait more common

7

fishers sex ratio model is based on what type of selection?

negative frequency dependent selection

8

genetic drift does what to genetic variation?

reduces

9

neutral theory?

most dna is neutral with respect to fitness