The origin of species

Question 1

speciation

Answer 1

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

Question 2

macroevolution

Answer 2

broad pattern of evolution, above species

Question 3

biological species concept

Answer 3

species are defined by reproductive isolation; Mayr

Question 4

reproductive isolation

Answer 4

when biological barriers impede members from two species from interbreeding and producing viable, fertile offspring

Question 5

hybrids

Answer 5

offspring that result from interspecific mating

Question 6

prezygotic barriers

Answer 6

biological barriers that block fertilization

Question 7

postzygotic barriers

Answer 7

biological barriers that contribute to reproductive isolation after fertilization

Question 8

habitat/ecological isolation

Answer 8

two species occupy different habitats and don’t interact; prezygotic barrier

Question 9

temporal isolation

Answer 9

two species breed during different times; prezygotic barrier

Question 10

behavioral isloation

Answer 10

two species don’t decide to mate based on behavior; prezygotic barrier

Question 11

mechanical isolation

Answer 11

mating attempted but it just won’t fit…; prezygotic barrier

Question 12

gametic isolation

Answer 12

species mate but fertilization never happens; prezygotic barrier

Question 13

reduced hybrid viability

Answer 13

hybrids are don’t survive well; postzygotic barrier

Question 14

reduced hybrid fertility

Answer 14

hybrids can’t reproduce well; postzygotic barrier

Question 15

hybrid breakdown

Answer 15

the hybrid offspring don’t survive well and/or reproduce well; postzygotic barrier

Question 16

morphological species concept

Answer 16

species are defined by their structural features (looking alike)

Question 17

ecological species concept

Answer 17

species are defined by their ecological niche (interacting similarly with their environment, having similar requirements)

Question 18

phylogenetic species concept

Answer 18

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

Question 19

allopatric speciation

Answer 19

the formation of a new species in populations that are geographically isolated from one another

Question 20

sympatric speciation

Answer 20

the formation of a new species in populations that live in the same geographic area; requires a reproductive barrier

Question 21

polyploidy

Answer 21

having extra sets of chromosomes; contributes to sympatric speciation

Question 22

autopolyploid

Answer 22

an individual that has more than two chromosome sets that are derived from a single species

Question 23

allopolyploid

Answer 23

a fertile individual that has more than two chromosome sets as a result of two different species interbreeding and combining their chromosomes

Question 24

habitat differentiation

Answer 24

when genetic factors enable a subpopulation to exploit a habitat or resource not used by the parent population; contributes to sympatric speciation

Question 25

sexual selection and sympatric speciation

Answer 25

sexual selection can contribute to sympatric speciation if there are subgroups with different preferences in choosing a mate

Question 26

hybrid zone

Answer 26

a region in which members of different species meet and mate, producing at least some offspring of mixed ancestry

Question 27

reinforcement in hybrid zone

Answer 27

strengthening of reproductive barriers, hybrids gradually cease to be formed

Question 28

fusion in hybrid zone

Answer 28

weakening of reproductive barriers, the two species fuse

Question 29

stability in hybrid zone

Answer 29

continued production of hybrid individuals

Question 30

punctuated equilibria

Answer 30

periods of apparent stasis, and change as speciation occurs; in contrast to gradual continuous change

Question 31

species cluster

Answer 31

a group of closely related species recently descended from a common ancestor

Question 32

ring species

Answer 32

a species with a geographical distribution that forms a ring around uninhabitable terrain; a kind of cline

Question 33

parapatric speciation

Answer 33

speciation between populations with adjacent geographical distributions

Question 34

cline

Answer 34

a graded change in character along a geographic axis