Chapter 15

Question 1

Speciation

Answer 1

process by which one species splits into two or more species

Question 2

New species resulting from speciation share..

Answer 2

many characteristics because they descend from common ancestor

Question 3

Speciation increases

Answer 3

diversity of life

Question 4

Biological species concept

Answer 4

group of populations whose members have the potential to interbred in nature and produce fertile offspring

Question 5

Biological species concept is useless for

Answer 5

defining prokaryotes

Question 6

Biological species concept is problematic for defining

Answer 6

species of fossils

Question 7

Morphological species concept

Answer 7

based on distinguishing physical traits

Question 8

Morphological species concept can be applied to

Answer 8

fossils, asexualling and sexually reproducing organisms

Question 9

Ecological species concept

Answer 9

defines species by its ecological role or niche

Question 10

Ecological species concept focuses on

Answer 10

unique adaptions to a particular role in biological community

Question 11

Phylogenetic species concept

Answer 11

defines species as the smallest group of individuals which share a common ancestor, each species forms 1 branch on tree of life

Question 12

Phylogenetic species concept is problematic to..

Answer 12

determined amount of difference required separate species

Question 13

Species interbreed resulting in

Answer 13

hybrids

Question 14

Reproductive barriers

Answer 14

• prezygotic

- postzygotic

Question 15

5 types of pre zygotic barriers

Answer 15

habitat isolation

• temporal isolation
• behavioural isolation
• mechanical isolation
• gametic isolation

Question 16

Habitat isolation

Answer 16

two species live in same general are but not same kind of place

Question 17

Temporal isolation

Answer 17

two species breed at different times

Question 18

Behavioural isolation

Answer 18

there is little or no mate recognition between females and males of diff species

Question 19

Mechanical isolation

Answer 19

female and male sex organs are not compatible

Question 20

Gametic isolation

Answer 20

female and male games are not compatible

Question 21

3 types of post zygotic barriers

Answer 21

• reduced hybrid viability
• reduced hybrid fertility
• hybrid breakdown

Question 22

Reduced hybrid viability

Answer 22

most hybrid offspring do not survive

Question 23

Reduced hybrid fertility

Answer 23

hybrid offspring are vigorous but sterile

Question 24

Hybrid breakdown

Answer 24

first generation hybrids are viable and fertile but offspring of hybrids are sterile

Question 25

Allopatric speciation

Answer 25

populations of the same species are geographically operated isolating their gene pools

Question 26

Isolated population will no longer share changes in allele frequencies caused by

Answer 26

- natural selection - genetic drift - mutation

Question 27

Gene flow between population is initially prevent by..

Answer 27

geographic barriers

Question 28

Sympatric speciation

Answer 28

occurs when a new species arises within the same geographic area as parent species

Question 29

Gene flow between population may be reduced by

Answer 29

- polyploidy - habitat differentiation - sexual selection

Question 30

Most plants we grow for food are..

Answer 30

polyploids

Question 31

Wheat species Have evolved for..

Answer 31

10,000 years

Question 32

Allopatric speciation is the cause for..

Answer 32

most diversity on Earth

Question 33

Adaptive radiation

Answer 33

evident in islands because far enough apart to permit evolution in isolating but close enough to allow occasional gene flow

Question 34

Hybrid zones

Answer 34

regions in which members of different species mate producing hybrid offspring

Question 35

3 possible outcomes of hybrid zones

Answer 35

- reinforcement - fusion - stability

Question 36

Reinforcement

Answer 36

hybrid offspring are not fit, natural selection reinforces reproductive barriers

Question 37

Fusion

Answer 37

reproductive barriers are not strong, speciation process reverses

Question 38

Stability

Answer 38

hybrids continue to be produced but each species maintains its own integrity

Question 39

Punctuated equilibria

Answer 39

long periods of little speciation interpreted by abrupt epodes of speciation

Question 40

Time between speciation event averaged ___ ______ years and rarely took less than ______ years

Answer 40

6.5 million; 50,000