Unit 7: Natural Selection Flashcards
(25 cards)
speciation
procress where one species splits into two or more
reproductive isolation
mechanizm that prevents two species from producing viable and fertile offspring
prezygotic barrier
preventing fertilization
habitat isolation
geologically separated preventing mating
temporal isolation
active during different times of day
behavioral isolation
searching for specific traits that they want to mate with
mechanical isolation
two reproductive organs are not compatible
gametic isolation
protein of an egg will only recognize sperm of same species
postzygotic isolation
offspring of species are not able to survive or reproduce
reduced hybrid viability
offspring cannot live on its own
reduced hybrid fertility
offspring cannot reproduce on its own
hybrid breakdown
generation F1 is fertile and viable but generation F2 has reduced viability and fertility
allopatric speciation
forms new species because of geological barrier
sympatric speciation
a new species forms within a population without geological barriers
founder effect
group of individuals become isolated from larger population establish a new population
bottleneck effect
significant reduction in population due to a natural disaster
evolutionary fitness
individual’s ability to survive and reproduce
Genetic drift
change in allele frequency overtime
Gene flow
movement of genetic material from one population to another (migration)
stabilizing selection
individuals with extreme traits are eliminated
disruptive selection
individuals with extreme traits are favored
homologous structures
similar features that organisms have suggesting common ancestor
Divergent evolution
species from same common ancestor becomes different overtime which can lead to speciation
Convergent evolution
unrelated species develop similar traits because of environment pressure
