Chapter 3

Question 1

**microevolution

Answer 1

A subfield of evolutionary studies that devotes attention to short-term evolutionary changes that occur within a given species over relatively few generations of ecological time.

Question 2

**macroevolution

Answer 2

A subfield of evolutionary studies that focuses on long-term evolutionary changes, especially the origins of new species and their diversification across space and over millions of years of geological time.

Question 3

–species

Answer 3

A reproductive community of populations (reproductively isolated from others) that occupies a specific niche in nature.

Question 4

gene pool

Answer 4

All the genes in the bodies of all members of a given species (or a population of a species).

Question 5

gene frequency

Answer 5

The frequency of occurrence of the variants of particular genes (i.e., of alleles) within the gene pool.

Question 6

population genetics

Answer 6

A field that uses statistical analysis to study short-term evolutionary change in large populations.

Question 7

polymorphous

Answer 7

Describes alleles that come in a range of different forms.

Question 8

cline

Answer 8

The gradual intergradation of genetic variation from population to population.

Question 9

–natural selection

Answer 9

A two-step, mechanistic explanation of how descent with modification takes place: (1) every generation, variant individuals are generated within a species due to genetic mutation and (2) those variant individuals best suited to the current environment survive and produce more offspring than other variants.

Question 10

mutation

Answer 10

The creation of a new allele for a gene when the portion of the DNA molecule to which it corresponds is suddenly altered.

Question 11

**gene flow

Answer 11

The exchange of genes that occurs when a given population experiences a sudden expansion due to in-migration of outsiders from another population of the species.

Question 12

**genetic drift

Answer 12

Random changes in gene frequencies from one generation to the next due to a sudden reduction in population size as a result of disaster, disease, or the out-migration of a small subgroup from a larger population.

Question 13

plasticity

Answer 13

Physiological flexibility that allows organisms to respond to environmental stresses, such as temperature changes.

Question 14

adaptation

Answer 14

(1) The mutual shaping of organisms and their environments. (2) The shaping of useful features of an organism by natural selection for the function they now perform (see Chapter 2).

Question 15

acclimatization

Answer 15

A change in the way the body functions in response to physical stress.

Question 16

formal models

Answer 16

Mathematical formulas to predict outcomes of particular kinds of human interactions under different hypothesized conditions.

Question 17

anagenesis

Answer 17

The slow, gradual transformation of a single species over time.

Question 18

**phyletic gradualism

Answer 18

A theory arguing that one species gradually transforms itself into a new species over time, yet the actual boundary between species can never be detected and can only be drawn arbitrarily.

Question 19

cladogenesis

Answer 19

The birth of a variety of descendant species from a single ancestral species.

Question 20

**punctuated equilibrium

Answer 20

A theory claiming that most of evolutionary history has been characterized by relatively stable species coexisting in an equilibrium that is occasionally punctuated by sudden bursts of speciation, when extinctions are widespread and many new species appear.

Question 21

species selection

Answer 21

A process in which natural selection is seen to operate among variant, related species within a single genus, family, or order.

Question 22

**Sociobiology

Answer 22

School of thought that believed everything humans did could be traced back to their individual genetic makeup…
“Systematic study of the biological basis of all social behavior”

Question 23

**Evolutionary Psychology

Answer 23

Like Sociobiology, but doesn’t think that natural selection has a bearing on human behavior patterns via genes in present day. Believe this was most significant millions of years ago when we split off from apes.

Question 24

**Behavioral Ecology

Answer 24

Accepts the view that human adaptations depend on cultural learning rather than on genetic control, but insist that the cultural behavior human beings develop is closely circumscribed by the selectino pressures imposed upon us by the ecological features of the environments in which human populations have lived.