CH 24 Flashcards
speciation
-process by which one species splits into two species
biological species concept
-a species is a group of populations whose members have the potential to inbreed in nature and produce viable, fertile offspring-not with other groups
reproductive isolation
-the existence of biological factors that impede members of two species from interbreeding and producing viable, fertile offspring
Habitat isolation
-prezygotic barriers
-two species that occupy different habitats within the same area will rarly encounter each other, if at all
-land and water
temporal isolation
-prezygotic barriers
-species that breed during different times cannot mix gametes
behavioral isolation
-prezygotic barriers
-courtship rituals are unique to a species will not work on other species
mechanical isolation
-prezygotic barriers
-mating is attempted but the pieces don’t fit together
gametic isolation
-prezygotic barriers
-sperm of one species may not be able to fertilize the eggs of another species
reduced hybrid viability
-postzygotic barrier
-the gene of different parent species may interact in ways that impair hybrids development/survival in environment
reduced hybrid fertility
-postzygotic barrier
-even if hybrid is vigorous, maybe sterile
-horse + donkey = mule
hybrid breakdown
-postzygotic barrier
-some first gen hybrids are viable/fertile, but when they mate offspring are not viable and fertile
allopatric speciation
-the formation of new species in populations that are geometrically isolated from one another
sympatric speciation
-the formation of new species in populations that live in the same geographic location
hybrid zones
-a region where members of different species meet and mate, producing at least some mixed offspring
reinforcement
-strengthening reproductive barriers
-hybrid zones
