Chapter 24 the origin of species

Question 1

speciatoin

Answer 1

the origin of new species

Question 2

microevolution

Answer 2

changes in allele freq over time in a pop

Question 3

macroevolution

Answer 3

broad pattern of evolutonary change above the species level

Question 4

bsc

Answer 4

a species is a group of pop whose members have the potential to interbreed in nature and produce vaible, fertile offspring; they do not breed successfully with other populations.

cannot be applied to fossils or asexual organisms (all prokaryotes)

Question 5

reproductive isolation

Answer 5

the existence of biological factors that impede two species from producing viable, fertile offspring

Question 6

hybrids

Answer 6

offspring of crosses between two species

Question 7

prezygotic barriers

Answer 7

block fertilization from occuring by impeding different species from attempting to mate, precenting successful completion of mating, hindering fertilization if mating is successful

Question 8

postzygotic barriers

Answer 8

prevent the hybrid zygote from developing into a viable, fertile adult by reducing hybrid vaibility and fertility, and hybrid break down.

Question 9

Allopatric speciation

Answer 9

Gene flow is interrupted or reduced when a pop is divided into geographically isolated subpopulations

Question 10

Sympatric speciation

Answer 10

Takes place in geographically overlapping pops

Question 11

Polyploidy

Answer 11

The presence of extra sets of chromosomes due to accidents during cell division, plants

Question 12

Habitat differentiation

Answer 12

Sympatric speciation also results from the appearance of new ecological niches. Ex maggot fly

Question 13

Sexual selection

Answer 13

Can drive Sympatric speciation. Cichlid fish in lake Victoria

Question 14

Hybrid zone

Answer 14

A region in which members of diff species mate and produce hybrids. Incomplete reproductive barriers

Question 15

Reinforcement

Answer 15

Occurs when hybrids are less fit than the parent species

Question 16

Fusion

Answer 16

If hybrids are as fit as parents, there can be substantial gene flow between species. Cichlids in lake Victoria