Chapter 7 Flashcards
Species
Interbreeding populations that evolve independently of others
Morphospecies
Based on morphological similarities and differences
Cryptic species
Similar in morphology but may be different in other ways
Phylogenetic species concept
Monophyletic groups that contain all known descendants of a common ancestor
Biological species concept
Based off of reproductive isolation
Secondary contact
Reproductive isolation of two species that were originally one
Allopatric model of isolation
Physical isolation creates a barrier to gene flow
Vicariance
An existing habitat is physically separated
Dispersal
Some individuals from one area head off to another
Sympatric species
Those that overlap geographically, but differ in chromosome number
Assortative mating
Choosing a mating partner with traits similar to your own
Prezygotic isolation
Hybrid offspring are never formed, typically because mating did not happen
Postzygotic isolation
Hybrid offspring suffer from inviability, sterility, or reduced fitness
Reinforcement
Selection that reduces the frequency of hybrids
Gametic isolation
Gametes from the same species are preferentially selected to produce zygotes