Evolution

Question 1

What are the three things required for evolution by natural selection?

Answer 1

Heritability of trait, variety of trait, differential selection

Question 2

Define natural selection

Answer 2

The nonrandom mechanism by which the frequency of a trait in a population changes over time due to the beneficial or detrimental effect that it has on an organism’s ability to survive and pass on the trait.

Question 3

Define evolution

Answer 3

The change in the frequency of a trait over time in a population

Question 4

What are the four mechanisms of evolution?

Answer 4

Natural selection, genetic drift, mutation, and migration

Question 5

What is fixation?

Answer 5

When the variety of a certain trait drops to zero (i.e. all the members of the population possess the same variation of that trait)

Question 6

Define genetic drift

Answer 6

The change in the frequency of a certain trait in a population over time due to random chance alone

Question 7

What does population size have to do with genetic drift?

Answer 7

Smaller populations are affected more strongly by genetic drift because it is easier to skew the frequency of a trait in a smaller population

Question 8

How can natural selection or genetic drift cause biodiversity?

Answer 8

If these forces are applied differently to populations of the same species in different geographic regions, the populations can become different from each other and diverge

Question 9

What facilitates the diversity of life via natural selection or genetic drift?

Answer 9

The presence of a physical barrier to separate a population into groups where the mechanisms of evolution can manifest themselves differently (e.g. island, mountain range, river, etc.)