Ch 24

Question 1

speciation

Answer 1

process by which one species splits into two species

Question 2

microevolution

Answer 2

consists of changes in allele frequency in a population over time

Question 3

macroevolution

Answer 3

refers to broad patterns of evolutionary change abovee the species level

Question 4

biological species concept

Answer 4

group of pop whose members have the potential to interbreed in nature, produce fertile offspring, and don’t produce fertile offspring with members of other groups

Question 5

reproductive isolation

Answer 5

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

Question 6

hybrids

Answer 6

offspring that results from interspecific mating

Question 7

Prezygotic barriers

Answer 7

habitat isolation, temporal isolation, behavioral isolation, mechnical isolation, gametic isolation

Question 8

postzygotic barriers

Answer 8

reduced hybrid viability, reduced hybrid fertility, hybrid breakdown

Question 9

temporal isolation

Answer 9

species that breed at different times of the day, in different seasons, or different years cannot mix their gametes

Question 10

ex of temporal isolation

Answer 10

western spotted skunks mate in summer and eastern spotted skunks mate in winter

Question 11

behavioral isolation

Answer 11

courtship rituals & o/ behaviors unique to a species are effective barriers to mating

Question 12

ex of behavioral isolation

Answer 12

blue-fottes boobies, mate only after a unique courtship display

Question 13

mechanical isolation

Answer 13

mating is attempted, but morphological differences prevent its successful completion

Question 14

ex of mechanical isolation

Answer 14

genetial openings of snails in genus Bradynaena don’t align if their shells spiral in opposite directions

Question 15

gametic isolation

Answer 15

sperm of one species may not be ablt to fertilize eggs of another species

Question 16

ex of gametic isolation

Answer 16

surface proteins on the sperm and eggs of diff sea urchins bind poorly to e/ o/, preventing fusion & zygote formation

Question 17

reduced hybrid viability

Answer 17

genes of diff parent species may interact in ways that impair the hybrid’s devlopment or survival in its enviornment

Question 18

ex of reduced hybrid viabilility

Answer 18

hybrid offspring of diff subspecies of salamanders of the genus Ensatina do not usaully complete dev

Question 19

reduced hybrid fertility

Answer 19

meiosis may fail to produce normal gametes, resulting in sterility, if the parent species have chromosomes of diff number or structure

Question 20

ex of reduced hyrbid fertility

Answer 20

the hybrid offspring of a male donkey and femal horse, a mule, is robust, but sterile

Question 21

hybrid breakdown

Answer 21

first-generation hybrids are viable & fertile, but offspring in the next generation are feeble or sterile

Question 22

ex of hybrid breakdown

Answer 22

hybrids btw certain strains of cultivated rice are vigorous & fertile , but members of next gen are small and sterile

Question 23

speciation can occur in 2 ways

Answer 23

allopatric & sympatric

Question 24

allopatric speciation

Answer 24

populations are geographically isolated

Question 25

sympatric speciation

Answer 25

populations are not geographically isolated