Study Goals Exam 3 Week 10

Question 1

What is genetic drift?

Answer 1

A change in allele frequencies in a population that is due to chance

Question 2

What causes genetic drift in natural populations?

Answer 2

Sampling error which is when the allele frequencies of a chosen sample of a population are different from those in the total population, by chance

Question 3

Gene Flow

Answer 3

The movement of alleles between populations

Question 4

What role does mutation play in evolution?

Answer 4

Slow compared to selection, genetic drift, & gene flow but when combined with these can be large

Question 5

Why can’t evolution happen without mutation?

Answer 5

Eventually there would be no variation for selection to act on, & alleles that were not lost would become fixed

Question 6

How are species defined and identified?

Answer 6

-Evolutionarily independent population or group of populations
-identified by the biological species concept, the morphospecies concept, & phylogenetic species concept

Question 7

Biological Species Concept

Answer 7

No gene flow occurs between populations that are reproductively isolated from each other

Question 8

Morphospecies Concept

Answer 8

Distinguishing features are most likely to arise if populations are independent and isolated from gene flow

Question 9

Phylogenetic Species Concept

Answer 9

Based on the evolutionary history of populations, all species form a monophyletic (“one-tribe”) group —the tree of life

Question 10

Allopatry

Answer 10

Populations that are geographically separated

Question 11

How is allopatry related to vicariance?

Answer 11

Allopatric speciation starts through vicariance which is the physical splitting of a habitat

Question 12

Allopatric Speciation

Answer 12

Geographic isolation that leads to reproductive isolation