biology: evolution of species Flashcards
morphology species concept
if they look alike they are same species
problem:juvenile v. adult
different breeds
formation of new species theories
morphology species concept
biological species concept
if they can interbreed and produce fertile offspring then they are one species
problem : asexual reproduction
phylogenetic species concept
smallest group of individuals that share a common ancestor
problem: cant always agree on common ancestor
How does a new species form?
Geographic isolation
Allopatric speciation
Population geographically isolated from parent population
Gene glow stops natural selection and genetic drift cause speciation
Adaptive evolution
Evolution of many diverse species from a common ancestor
Sympatric speciation
Reproductive isolation
Small part of population becomes new population without geographic isolation
Amused by habitual differences
Polyploidy (extra chromosomes)
Sub population exploits habitat/ resource not exploited by parent population
Hybrid zone
Area where different species overlap
Produce some hybrid offspring
Prezygotic barriers
Barriers that prevent a zygote from forming
Habitat isolation
Prezygote
Species do not encounter each other
Behavioral isolation
Species does not recognize another species as mating partner
Temporal isolation
Different mating seasons
Mechanical isolation
Male and female generalized are structurally incompatible
Gametic isolation
Female gametes don’t recognize male gametes
