Topic 6- Speciation Flashcards
Speciation
Is the process by which, one species splits into two or more species
Biological species concept
Biological species are groups that actually or potentially interbreed and produce fertile offspring in nature, and which do not form fertile offspring with members of other groups.
Reproductive isolation
Is the opposite of compatibility; it is the result of reproductive barriers- defined as biological features of organisms that reduce or prevent gene exchange with members of other groups
Species Concepts- Morphological
defines species based on morphological similarity
Species concepts- Ecological
defines species based on their ecological niche (the physcial and enviromental conditions it requires and the interactions it has with other species
Reproductive barrier- Prezygotic
-Before fertilization/before mating
-block fertilization by reducing the likelihood of mating, by preventing an attempted mating from being success, or by impeding fertilization after a successful mating
Reproductive barrier- Postzygotic
-After fertilization/after mating
-Reduce the survival/or and reproductive success of hybrids–> Reduce the fitness of hybrids
Geography of populations - Allopatric
Occurring in separate, non-overlapping geographic areas
Geography of populations- Sympatric
Occurring in the same, overlapping geographic area
Mechanisms of speciation
Ecological, polyploidization, reinforcement