Anthropology: what does it mean to be human chapter 3

A subfueld of evolutionary studies that devotes attention to short-term evolutionary change that occur within a given species over relatively few generations of ecological time
A subdued 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
A distinct segment of evolutionary lineage. Different biologists working with living and fossil organisms, have devised different criteria to identify boundaries between species
Gene pool
All the genes in the bodies of all members of a given species for a population of a species
Gene frequency
The frequency of occurrence of the variants of particular genes within a gene pool
Population genetics
A field that uses statistical analysis to study short-term evolutionary change in large populations
Describes alleles that come in a range of different forms
A pattern of gradually shifting frequency of a phenotypic trait from population to population across geographic space
Natural selection
A two-step mechanistic explanation of how descent with modification takes place: (1) every generation, variant individuals are generated within a species as a result of genetic mutation, and (2) those variant individuals best suited to the current environment survive and produce more offspring than other variants
The creation of a new allele for a gene when the portion of the DNA molecule to which it corresponds is suddenly altered
Gene flow
The exchange of genes that occurs when a given population experiences a sudden expansion caused by in-migration of outsiders from another population of the species
Genetic drift
Random changes in gene frequencies from one generation to the nest caused by a sudden reduction in population size as a result of disaster, disease, or the out-migration of a small subgroup from a larger population
Phenotypic plasticity
Physiological flexibility that allows organisms to respond to environmental stresses, such as temperature changes
(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
A change in the way the body functions in response to physical stress
Formal models
Mathematical formulas to predict outcomes of particular kinds of human interactions under different hypothesized conditions
The slow, gradual transformation of a single species over time
Phyletic gradualism
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
The birth of variety of descendent species from a single ancestral species
Punctuated equilibrium
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
Species selection
A process in which natural selection is seen to operate among variant, related species within a single genus, family, or order

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