speciation Flashcards
species
populations of individuals that can interbreed under natural conditions and producing viable offspring
speciation/macroevolution
formation of a new species from existing species
reproductive isolating mechanism
any heritable feature that prevents breeding between genetically divergent populations
reproductive isolating mechanism
pre-zygotic
prevent mating or prevent fertilization of eggs
pre-zygotic prevention of mating
behavioural isolation
behaviours that prevent individuals from selecting them for mating
pre-zygotic prevention of mating
temporal isolation
different mating times
pre-zygotic prevention of mating
habitat isolation
species that live in same general area but different habitats, therefore they do not encounter each other
pre-zygotic prevention of fertilization
mechanical isolation
anatomically incompatible
pre-zygotic prevention of fertilization
gametic isolation
gametes are incompatible
reproductive isolating mechanism
post-zygotic
prevents hybrid offspring from developing into viable adults
post-zygotic
hybrid inviability
development of hybrid zygote stops in early development
post-zygotic
hybrid sterility
hybrid produced is sterile
post-zygotic
hybrid breakdown
f1hybrid forms but f2 hybrids are not viable
modes of speciation
allopatric speciation
evolution of populations into separate species as a result of geographic isolation
modes of speciation
sympatric speciation
evolution of populations into separate species within the same geographic area
allopatric speciation
adaptive radiation
ancestral species diversifies into differently adapted species
divergent evolution
as populations adapt, they become less and less alike
convergent evolution
species are similar in phenotypes due to similar environments
speed of evolutionary change
gradualism
evolutionary change is slow and steady
speed of evolutionary change
punctuated equilibrium
evolutionary change in spurts
