Speciation

Question 1

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

Answer 1

speciation

Question 2

What does speciation do?

Answer 2

bridges microevolution & macroevolution

Question 3

change in allele frequency in population over time

Answer 3

microevolution

Question 4

broad patterns of evolutionary change above the species level

Answer 4

macroevolution

Question 5

a group of population whose members can interbreed and produce fertile, viable offspring

Answer 5

species

Question 6

What does the biological species concept believe?

Answer 6

(1) gene flow holds populations together genetically
(2) reproductive isolation keeps species apart
(3) phenotypic similarities or differences don’t matter

Question 7

when biological barriers impede 2 species from producing viable, fertile offspring

Answer 7

reproductive isolation

Question 8

Types of reproductive isolation

Answer 8

pre-zygotic barriers & post-zygotic barriers

Question 9

offspring of crosses between different species

Answer 9

hybrids

Question 10

blocks fertilization by hindering mating or fertilization

Answer 10

pre-zygotic barriers

Question 11

5 types of pre-zygotic barriers

Answer 11

(1) habitat isolation
(2) temporal isolation
(3) behavioral isolation
(4) mechanical isolation
(5) gametic isolation

Question 12

Which type of pre-zygotic isolation deals with water versus land?

Answer 12

habitat

Question 13

Which type of pre-zygotic isolation includes mating in the summer versus winter?

Answer 13

temporal

Question 14

Which type of pre-zygotic isolation includes knowing mating rituals?

Answer 14

behavioral

Question 15

Which type of pre-zygotic isolation is where the organisms are physically inhibited from mating?

Answer 15

mechanism

Question 16

Which pre-zygotic isolation is where gametes cannot fuse?

Answer 16

gametic

Question 17

prevents the hybrid zygote form developing into a viable, fertile adult

Answer 17

post-zygotic barrier

Question 18

3 types of post-zygotic barriers

Answer 18

(1) reduced hybrid viability
(2) reduced hybrid fertility
(3) hybrid breakdown

Question 19

Which type of post-zygotic barrier is where the offspring have low fitness?

Answer 19

reduced hybrid viability

Question 20

Which type of post-zygotic barrier is where the number of chromosomes in parents affect the fertility of offspring?

Answer 20

reduced hybrid fertility

Question 21

Which type of post-zygotic barrier is where the offspring of hybrid are sterile?

Answer 21

hybrid breakdown

Question 22

What are the limitations to the biological species concept?

Answer 22

(1) cannot be applied to fossils or asexual organisms
(2) difficult to apply to allopatric population
(3) emphasizes absence of gene flow, but gene flow can occur between species

Question 23

populations that live in different geographic locations

Answer 23

allopatric

Question 24

groups species by structural features

Answer 24

morphological species concept

Question 25

groups species by ecological niche

Answer 25

ecological species concept

Question 26

groups species as the smallest group of individuals on a phylogenetic tree

Answer 26

phylogenetic species concept

Question 27

Types of speciation

Answer 27

allopatric & sympatric

Question 28

What are the mechanisms of allopatric speciation?

Answer 28

(1) populations are geographically isolated
(2) reproductive isolation arises by natural selection, genetic drift, or sexual selection
(3) ‘barriers’ depend on the organisms’ dispersal
(4) interbreeding is no longer possible even if contact is restored

Question 29

What are the mechanisms of sympatric speciation?

Answer 29

(1) populations live in the same geographic area
(2) they are in contact, but gene flow between theme is reduced

Question 30

How is gene flow reduced in sympatric selection?

Answer 30

polyploidy, natural selection, & sexual selection

Question 31

On average, how long does speciation last?

Answer 31

6.5 million years

Question 32

periods of no change punctuated by short bursts of rapid change

Answer 32

punctuated equilibrium

Question 33

gradual change over a long period of time

Answer 33

gradualism

Question 34

What is the time range of speciation?

Answer 34

4,000 to 40 million years

Question 35

Does speciation involve few or many genes?

Answer 35

few