Ch.26

Front 1

allopatric speciation

Back 1

The divergence of populations into different species by physical isolation of populations in different geographic areas

Front 2

allopatry

Back 2

Condition in which two or more populations live in different geographic areas. Compare with sympatry

Front 3

allopolyploid

Back 3

The state of having more than two full sets of chromosomes (polyploidy) due to hybridization between different species

Front 4

autopolyploid

Back 4

The state of having more than two full sets of chromosomes (polyploidy) due to a mutation that doubled the chromosome number

Front 5

biogeography

Back 5

The study of how species and populations are distributed geographically

Front 6

biological species concept

Back 6

The definition of a species as a population or group of populations that are reproductively isolated from other groups. Members of a species have the potential to interbreed in nature to produce viable, fertile offspring but cannot produce viable, fertile hybrid offspring with members of other species. Compare with morphological and phylogenetic species concept

Front 7

cryptic species

Back 7

A species that cannot be distinguished from other species by easily identifiable morphological traits

Front 8

hybrid zone

Back 8

A geographic area where interbreeding occurs between two species, sometimes producing fertile hybrid offspring

Front 9

monophyletic group

Back 9

An evolutionary unit that includes an ancestral population and all of its descendants but no others. Also called a clade or lineage. Compare with paraphyletic group

Front 10

morphospecies concept

Back 10

The definition of a species as a population or group of populations that have measurably different anatomical features from other groups. Also called morphospecies concept. Compare with biological and phylogenetic species concept

Front 11

phylogenetic species concept

Back 11

The definition of a species as the smallest monophyletic group in a phylogenetic tree. Compare with biological and morphological species concept.

Front 12

polyploidy

Back 12

The state of having more than two full sets of chromosomes

Front 13

postzygotic isolation

Back 13

Reproductive isolation resulting from mechanisms that operate after mating of individuals of two different species occurs. The most common mechanisms are the death of hybrid embryos or reduced fitness of hybrids

Front 14

prezygotic isolation

Back 14

Reproductive isolation resulting from mechanisms that operate after mating of individuals of two different species occurs. The most common mechanisms are the death of hybrid embryos or reduced fitness of hybrids

Front 15

reinforcement

Back 15

In evolutionary biology, the natural selection for traits that prevent interbreeding between recently diverged species

Front 16

sister species

Back 16

Closely related species, which occupy adjacent branches in a phylogenetic tree

Front 17

species

Back 17

A distinct, identifiable group of populations that is thought to be evolutionarily independent of other populations and whose members can interbreed. Generally distinct from other species in appearance, behavior, habitat, ecology, genetic characteristics, etc

Front 18

subspecies

Back 18

A population that has distinctive traits and some genetic differences relative to other populations of the same species but that is not distinct enough to be classified as a separate species

Front 19

sympatric speciation

Back 19

The divergence of populations living within the same geographic area into different species as the result of their genetic (not physical) isolation. Compare with allopatric speciation

Front 20

sympatry

Back 20

Condition in which two or more populations live in the same geographic area, or close enough to permit interbreeding. Compare with allopatry

Front 21

vicariance

Back 21

The physical splitting of a population into smaller, isolated populations by a geographic barrier