Chapter 24

Question 1

Speciation

Answer 1

The process by which one species splits into two or more species

Question 2

Microevolution

Answer 2

Changes in allele frequencies over time

Question 3

Macroevolution

Answer 3

the broad pattern of evolution above the species level

Creates new species

Question 4

Species definition

Answer 4

A group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring

Question 5

Morphological species concept

Answer 5

Characterizes species by body shape and other structural features

Useful to use without knowledge of gene flow

Subjective

Question 6

Ecological Species Concept

Answer 6

Views species within their niche

Categorizes based on interactions with biotic and abiotic components of its niche

Emphasizes natural selection filling new niches (disruptive)

Question 7

Phylogenic Species Concept

Answer 7

Defined species as the smallest group of individuals that share a common ancestor

Hard to determine when two populations are different enough to be considered new species

Question 8

Reproductive isolation

Answer 8

The existence of biological factors that impede members of two species from interbreeding and producing fertile offspring

Question 9

Prezygotic barriers

Answer 9

Block fertilization from occuring

Question 10

Postzygotic barriers

Answer 10

Contribute to reproductive isolation after a hybrid is formed

Question 11

Habitat isolation

Answer 11

Two species may occupy different habitats in the same area and rarely encounter each other

Question 12

Temporal isolation

Answer 12

Species are isolated by time

They breed different different times of the day or year

Question 13

Behavorial isolation

Answer 13

Courtship rituals attract mates of the same species an d allow for species recognition

Rituals can prevent breeding with other similar types

Question 14

Mechanical isolation

Answer 14

Mating is attempted by morphological differences prevent its successful completion

Question 15

Gametic Isolation

Answer 15

Sperm of one species is not able to fertilize the egg of another

Question 16

Reduced Hybrid Viability

Answer 16

Postzygotic

Genes of different parent species may interact in ways that do not allow hybrids to survive in the wild

Question 17

Hybrid Breakdown

Answer 17

First generation hybrids are viable, but by the second generation they are frail

Question 18

Hybrid defintion

Answer 18

Offspring of two separate species

Question 19

Allopatric Speciation

Answer 19

Occurs when gene flow between a population is interrupted by a barrier

Predicts that populations of the same species that are geographically isolated should accumulate genetic differences

Question 20

Sympatric Speciation

Answer 20

They are in the same area. Do not have geographic isolation

For example: yellow and orange flowers

Question 21

Autopolyploid

Answer 21

Sympatric speciation

Creates a viable polyploid offspring

Question 22

Habitat Differentiation

Answer 22

Sympatric speciation

Example: a new type of apple in an area creates a new species of flies specifically drawn to that new apple

Question 23

Hybrid zone

Answer 23

The difference between two species. Where hybrids occur

If smaller, there is a better chance for the hybrid to survive

Question 24

Reinforcement

Answer 24

Strengthening of reproductive barriers

Hybrids are not formed

Species are more and more different

Question 25

Stability

Answer 25

Continued production of hybrid individuals

Question 26

Fusion

Answer 26

Weakening of reproductive barriers

the two species fuse together

Question 27

Punctuated equilibrium

Answer 27

Describes the sudden changes seen in the fossil record followed by long periods of stasis

New species are formed rapidly