Chapter24

Question 0

Changes over time in allele frequencies in a population

Answer 0

Microevolution

Question 1

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

Answer 1

Speciation

Question 2

The broad pattern of evolution above the species level

Answer 2

Macroevolution

Question 3

Concept that says a species is a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring with members of other such groups

Answer 3

Biological species concept

Question 4

The existence of biological factors that impede members of two species from interbreeding and producing viable, fertile offspring

Answer 4

Reproductive isolation

Question 5

Offspring that result from an Interspecific mating

Answer 5

Hybrids

Question 6

They block fertilization from occurring

Answer 6

Prezygotic barriers

Question 7

When a sperm cell fertilizes an ovum it is blocked by being isolated

Answer 7

Postzygotic barriers

Question 8

Two species that occupy different habitats within the same area may encounter eachother rarely, if at all, even though they are not isolated by obvious physical barriers, such as mountain ranges

Answer 8

Habitat isolation

Question 9

Species that breed during different times of the day, different seasons, or different years cannot mix their gametes

Answer 9

Temporal isolation

Question 10

Courtship rituals that attract mates and other behaviors unique to a species are effective reproductive barriers, even between closely related species. Such behavioral rituals enable mate recognition-a way to identify potential mates of the same species

Answer 10

Behavioral isolation

Question 11

Mating is attempted, but morphological differences prevent its successful completion

Answer 11

Mechanical isolation

Question 12

Speed of one species may not be able to fertilize the eggs of another species. For instance, sperm may not be able to survive in the reproductive tract of females of the other species, or biochemical mechanisms may prevent the speed from penetrating the membrane surrounding the other species’ eggs

Answer 12

Gamers isolation

Question 13

The genes of different parent species may interact in ways that impair the hybrid’s development or survival in its environment

Answer 13

Reduced Hybrid Viability

Question 14

Even if hybrids are vigorous, they may be sterile. If the chromosomes of the two parent species differ in number or structure, meiosis in the hybrids may fail to produce normal gametes. Since the infertile hybrids cannot produce offspring when they mate with either parent species, genes cannot flow freely between the species

Answer 14

Reduced Hybrid Fertility

Question 15

Some first-generation hybrids are viable and fertile, but when they mate with one another or with either parent species, offspring of the next generation are feeble or sterile

Answer 15

Hybrid Breakdown

Question 16

Characterizes a species by body shape and other structural features

Answer 16

Morphological species concept

Question 17

Views a species in terms of its ecological niche

Answer 17

Ecological species concept

Question 18

Defines a species as the smallest group of individuals that share a common ancestor, forming one branch on the tree of life

Answer 18

Phylogenetic species concept