Lecture 4

Question 1

Mechanisms of evolution

Answer 1

mutations
recombination

Question 2

Recombination

Answer 2

creates new combinations of alleles

Question 3

Types of natural selection

Answer 3

directional
stabilizing
disruptive

Question 4

Directional natural selection

Answer 4

individual with one extreme heritable phenotype is favored (eg. large)

Question 5

Stabilizing natural selection

Answer 5

individuals with intermediate phenotypes are favored

Question 6

Disruptive natural selection

Answer 6

individuals with either extreme phenotypes are favored (eg. both small and large are favored over medium)

Question 7

Genetic Drift

Answer 7

due to random events

Question 8

Gene flow

Answer 8

when alleles are transferred from one population to another via the movement of individuals or gametes

Question 9

Adaptive evolution

Answer 9

improves an organisms ability to survive and reproduce in its environment

Question 10

Clines

Answer 10

patterns of change in a characteristic of an organism over a geographic region

Question 11

Phenotypic Plasticity

Answer 11

some genotypes can produce different phenotypes in different environments

Question 12

Constraints on adaptive evolution

Answer 12

lack of genetic variation
evolutionary history
trade-offs

Question 13

Speciation

Answer 13

process where one species splits into 2 or more species

Question 14

Net diversity of a species

Answer 14

balance between the introduction of new species and extinction

Question 15

Mass extinction

Answer 15

events in which a large population of the Earth’s species were driven to extinction in a short time

Question 16

Adaptive radiation

Answer 16

event where a group of organisms gives rise to many new species that expand into new habitats or ecological roles in a relatively short time