Chapter 23: Origin of Species

Question 0

changes over time in allele frequency in a population over generations; evolutionary change below the species level

Answer 0

microevolution

Question 1

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

Answer 1

speciation

Question 2

the origin of a new group of organisms or a shift in the broad pattern of evolutionary change; evolutionary change above the species level

Answer 2

macroevolution

Question 3

definition of a species as a population or group of a populations whose members have the potential to interbreed in nature and produce viable, fertile offspring

Answer 3

biological species concept

Question 4

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

Answer 4

reproductive offspring

Question 5

“before the zygote”; prevents fertilization from occurring

Answer 5

pre-zygotic barriers

Question 6

“after the zygote”; contributes to reproductive isolation after hybrid zygote is formed

Answer 6

Post-zygotic barriers

Question 7

populations do not need to be separated by great distance. Instead, they must occupy different habitats, even within the same area.

Answer 7

habitat isolation

Question 8

courtship displays and rituals are vital to reproduction. Such behaviors can be very specific, varying between closely related species

Answer 8

Behavioral isolation

Question 9

Different populations may be ready to mate at different times of the year.

Answer 9

Temporal isolation

Question 10

Sperm from one species might not be able to fertilize egg of another species

Answer 10

Gametic isolation

Question 11

Genes of different parent species might interact in ways that impact the organisms development and survival in an environment

Answer 11

Reduced hybrid viability

Question 12

Even if the hybrids are vigarous, they might be sterile. If the parents chromosome structure or number is abnormal, meiosis in the hybrids will fail to produce fertile offspring, genes cannot flow freely between species

Answer 12

Reduced hybrid fertility

Question 13

The first generation hybrids are viable and fertile, but when they mate the offspring are feeble and sterile.

Answer 13

Hybrid breakdown

Question 14

mating is physically impossible. Often this occurs because the genitalia of different species are incompatible.

Answer 14

Mechanical isolation

Question 15

Gene flow is interrupted when a population is divided into geographically isolated populations

Answer 15

Allopatric speciation

Question 16

The formation of new species in populations that live in the same geographic area

Answer 16

Sympatric speciation

Question 17

An individual that has more than two chromosome sets that are all derived from the same species

Answer 17

Autopolyploid

Question 18

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

Answer 18

Allopolyploid

Question 19

Period of evolutionary change in which groups of organisms form many new species whose adaptation allow them to fill vacant ecological roles in their communities

Answer 19

Adaptive radiation

Question 20

Earth’s evolved through slow gradual change

Answer 20

Gradualism

Question 21

Long periods of apparent stasis, species undergo little or no morphological change, interrupted by relatively brief periods of sudden change

Answer 21

Punctuated equilibrium