Ch 15 Mechanisms of Evolution

Question 1

changes in the genetic make up of populations

Answer 1

microevolution

Question 2

describes the origin and extinction of species and the diversification of life

Answer 2

macroevolution

Question 3

the mechanism that drives evolution

Answer 3

natural selection

Question 4

the differential survival and reproduction of individuals in a population based on the variation in their traits

Answer 4

natural selection

Question 5

a group of individuals of a single species that live and interbreed in a particular geographic area at the same time

Answer 5

population

Question 6

the sum of all copies of all alleles at all loci found in a population

Answer 6

gene pool

Question 7

Human breeders that cross organisms to produce offspring with desired characteristics

Answer 7

artificial selection

Question 8

“favored” or “beneficial” trait

Answer 8

adaptation

Question 9

migration of individuals and movements of gametes between populations

Answer 9

gene flow

Question 10

random changes in allele frequencies from one generation to the next

Answer 10

genetic drift

Question 11

environmental events that only a small number of individuals survive

Answer 11

population bottleneck

Question 12

Caused when “pioneering” individuals colonize a new region. They are unlikely to have all available alleles in its gene pool.

Answer 12

founder effect

Question 13

nonrandom mating in which an organism’s phenotype influences its ability to attract mates

Answer 13

sexual selection

Question 14

a population with more than one allele at a locus

Answer 14

polymorphic

Question 15

Name the 5 conditions hat must be met for a population to be at Hardy-Weinberg equilibrium

Answer 15

• no mutations
• no differential selection among genotypes
• no gene flow
• population size is infinite
• mating is random