2.5 Mechanisms for Evolutionary Change (part 2: Modes of natural selection)

Question 1

What are the three modes of natural selection?

Answer 1

directional, stabilizing, and disruptive selection

Question 2

What mode of natural selection favors the phenotypic extremes?

Answer 2

Directional selection/Positive selection

Question 3

What mode of natural selection happens when an environment changes or when an organism migrates to a new environment?

Answer 3

Directional selection/Positive selection

Question 4

What is the difference between directional selection and the Founder effect?

Answer 4

The FOUNDER EFFECT results in GENETIC DRIF, meanwhile DIRECTIONAL SELECTION is a MODE OF NATURAL SELECTION

Question 5

What mode of natural selection favors extreme phenotypes over intermediate phenotypes?

Answer 5

Disruptive selection/diversifying selection

Question 6

What mode of natural selection favors extreme values of a trait over intermediate values?

Answer 6

Disruptive selection/diversifying selection

Question 7

What mode of natural selection favors INTERMEDIATE VARIANTS over extreme phenotypes?

Answer 7

Stabilizing selection

Question 8

What mode of natural selection REDUCES VARIATION in a selection?

Answer 8

Stabilizing selection

Question 9

What is the set of observable characteristics of an individual called?

Answer 9

Phenotype

Question 10

What is the difference between disruptive and directional selection?

Answer 10

Directional selection only favors particular extreme phenotype opposed to the others; Disruptive selection uses selection pressure to select against the average phenotype.