Speciation and Macroevolution

Question 1

Divergence

Answer 1

if gene flow ends, isolated populations can diverge, which can lead to speciation

Question 2

morphological species concept

Answer 2

organisms that look the same are the same species

Question 3

biological species concept

Answer 3

organisms that reproduce together represent the same species

Question 4

phylogenetic species concept

Answer 4

organisms that share evolutionary history are the same species

Question 5

ecological species concept

Answer 5

organisms that occupy the same ecological niche are the same species

Question 6

monophyletic group

Answer 6

an ancestral population and all descendants

Question 7

synapomorphy

Answer 7

shared, derived trait unique to a monophyletic group (black dashes on a phylogeny)

Question 8

prezygotic barriers

Answer 8

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

Question 9

postzygotic barriers

Answer 9

1) hybrid inviability
2) hybrid sterility
3) hybrid breakdown

Question 10

habitat isolation

Answer 10

species occupy different habitats in the same geographic range

Question 11

behavioral isolation

Answer 11

sexual selection

Question 12

temporal isolation

Answer 12

mating at different times

Question 13

mechanical isolation

Answer 13

1) incompatible genital organs

Question 14

gametic isolation

Answer 14

1) sperm of one species may not survive the environment of female in a closely related species
2) molecular recognition on the surface of eggs (proteins coating the eggs)

Question 15

hybrid inviability

Answer 15

hybrid embryos die when genetic regulation fails during embryonic development

Question 16

hybrid sterility

Answer 16

problems during meiosis cause abnormal gametes, sterile offspring

Question 17

hybrid breakdown

Answer 17

inability of second generation hybrid to reproduce because of some defect

Question 18

allopatric speciation

Answer 18

geographic separation of populations restricts gene flow

Question 19

sympatric speciation

Answer 19

new species arise within the range of the parent populations

Question 20

ring species

Answer 20

provide examples of what seem to be stages in the gradual divergence of new species from common ancestors

Question 21

adaptive radiation

Answer 21

evolution of many diversely-adapted species from a common ancestor is called an adaptive radiation

Question 22

endemic species

Answer 22

species found nowhere else in the world

Question 23

polyploidy

Answer 23

extra sets of chromosomes

Question 24

Hugo de Vries

Answer 24

produced a tetraploid primrose species from a diploid primrose species and they could not interbreed

Question 25

three types hybrid zones

Answer 25

1) reinforcement
2) fusion
3) stability

Question 26

reinforcement (hybrid zone)

Answer 26

strengthening of reproductive barriers

Question 27

fusion (hybrid zone)

Answer 27

weakening of reproductive barriers

Question 28

stability (hybrid zone)

Answer 28

continued production of hybrids

Question 29

hybrid vigor

Answer 29

hybrid has improved traits

Question 30

gradualism

Answer 30

continuous evolution over a long period of time

Question 31

punctuated equillibrium

Answer 31

long periods of stasis punctuated by period of rapid speciation