Chapter 12: Human Variation And Adaptation

Front 1

Acclimatization

Back 1

Physiological responses to changes in the environment that occur during an individual's lifetime. Such responses may be temporary or permanent, depending on the duration of the environmental change and when in the individual's life it occurs. The capacity for acclimatization may typify an entire species or population, and because it's under genetic influence, it's subject to evolutionary factors such as natural selection or genetic drift.

Front 2

Biological Determinism

Back 2

The concept that phenomena, including various aspects of behavior (e.g., intelligence, values, morals) are governed by biological (genetic) factors; the inaccurate association of various behavioral attributes with certain biological traits, such as skin color.

Front 3

Breeding isolates

Back 3

Populations that are clearly isolated geographically and/or socially from other breeding groups.

Front 4

Cline

Back 4

Populations that are clearly isolated geographically and/or socially from other breeding groups.

Front 5

Endemic

Back 5

Continuously present in a population.

Front 6

Eugenics

Back 6

The philosophy of race improvement through the forced sterilization of members of some groups and increased reproduction among others; an overly simplified, often racist view that is now discredited.

Front 7

Gene pool

Back 7

The total complement of genes shared by the reproductive members of a population.

Front 8

Hardy-Weinberg equilibrium

Back 8

The mathematical relationship expressing, under ideal conditions, the predicted distribution of alleles in populations; the central theorem of population genetics.

Front 9

Homeostasis

Back 9

A condition of balance, or stability, within a biological system, maintained by the interaction of physiological mechanisms that compensate for changes (both external and internal).

Front 10

Hypoxia

Back 10

Lack of oxygen. Hypoxia can refer to reduced amounts of available oxygen in the atmosphere (due to lowered barometric pressure) or to insufficient amounts of oxygen in the body.

Front 11

Intelligence

Back 11

Mental capacity; ability to learn, reason, or comprehend and interpret information, facts, relationships, and meanings; the capacity to solve problems, whether through the appplication of previously acquired knowledge or through insight.

Front 12

Lactase persistence

Back 12

The ability to continue to produce the enzyme lactase in adults. Most mammals, including humans, lose this ability after they are weaned.

Front 13

Neural tube

Back 13

In early embryonic development, the anatomical structure that develops to form the brain and spinal cord.

Front 14

Pandemic

Back 14

An extensive outbreak of disease affecting large numbers of individuals over a wide area; potentially a worldwide phenomenon.

Front 15

Pathogens

Back 15

Any agents, especially microorganisms such as viruses, bacteria, or fungi, that infect a host and cause disease.

Front 16

Polymorphisms

Back 16

Loci with more than one allele. Polymorphisms can be expressed in the phenotype as the result of gene action (as in ABO), or they can exist solely at the DNA level within noncoding regions.

Front 17

Polytypic

Back 17

Referring to species composed of populations that differ with regard to the expression of one or more traits.

Front 18

Population genetics

Back 18

The study of the frequency of alleles, genotypes, and phenotypes in populations from a microevolutionary perspective.

Front 19

Slash-and-Burn Agriculture

Back 19

A traditional land-clearing practice whereby trees and vegetation are cut and burned. In many areas, fields are abandoned after a few years and clearing occurs elsewhere.

Front 20

Spina Bifida

Back 20

A condition in which the arch of one or more vertebrae fails to fuse and form a protective barrier around the spinal cord.

Front 21

Stress

Back 21

In a physiological context, any factor that acts to disrupt homeostasis; more precisely, the body's response to any factor that threatens its ability to maintain homeostasis.

Front 22

Vasoconstriction

Back 22

Narrowing of blood vessels to reduce blood flow to the skin. Vasoconstriction is an involuntary response to cold and reduces heat loss at the skin's surface.

Front 23

Vasodilation

Back 23

Expansion of blood vessels, permitting increased blood flow to the skin. Vasodilation permits warming of the skin and also facilitates radiation of warmth as a means of cooling. Vasodilation is an involuntary response to warm temperatures, various drugs, and even emotional states (blushing).

Front 24

Vectors

Back 24

Agents that serve to transmit disease from one carrier to another. Mosquitoes are vectors for malaria, just as fleas are vectors for bubonic plague.

Front 25

Zoonotic

Back 25

Pertaining to a zoonosis (pl., zoonoses), a disease that is transmitted to humans through contact with nonhuman animals.