11 terms

Biology 16.3

the formation of new species as a result of evolution
the study of the structure and form of an organism
biological species concept
the concept that a species is a population of organisms that can interbreed but cannot breed with other populations
geographic isolation
the physical separation of populations due to geographic barriers that prevent interbreeding
allopatric speciation
happens when species arise as a result of geographic isolation; means "different homelands"
reproductive isolation
the inability of members of a population to successfully interbreed with members of another population of the same or a related species
prezygotic isolation
also called premating isolation, occurs before fertilization
postzygotic isolation
also called postmating isolation, occurs after fertilization
sympatric speciation
occurs when two subpopulations become reproductively isolated within the same geographic area; proposed by Darwin
the idea thta speciation ocurs at a regular, gradual rate
punctuated equilibrium
relative stability for long periods of time interspersed with much shorter periods during when many species become extinct and new species emerge; "punctuated" refers to sudden, rapid change and "equilibrium" refers to periods of little change