species and speciation

lecture terms

the biological species concept

the main criterion for identifying species is reproductive isolation

postzygotic isolation

a hybrid offspring that do not survive or reproduce

Prezygotic isolation

individuals of different species are prevented from mating successfully

morphospecies concept

if you look different, you are a different species

Niche

all of the biotic (living factors) and abiotic (nonliving factors) conditions a species can tolerate

ecological species concept

a species is a set of organisms that is adapted to a particular set of resources (niche) in the environment

phylogenetic species concept

identifies species based on evolutionary theory

speciation

splitting event that creates two or more distinct species from an ancestral species

allopatric speciation

speciation that begins with geographic isolation

dispersal in geographic isolation

population moves to a new habitat, colonizes, and finds a new population

vicariance in geographic isolation

the physical splitting of a habitat

sympatric speciation

living in same geographic location but still speciating

polyploidization

sympatric speciation in one generation

• mistakes that happen during cell replication that prevents them from reproducing because their chromosome count is messed