The origin of species Flashcards
What is the biological species concept?
Natural, interbreeding populations which produce viable, fertile offspring and are reproductively isolated from other such groups
What is reproductive isolation?
Populations do not mate with each other or do not produce fertile offspring
What are reproductive isolating mechanisms?
Traits of an organisms which are barriers to reproduction
What are gene pools?
Total set of alleles
What are prezygotic isolating mechanisms?
Prevent the formation of a zygote
What is postzygotic isolating mechanisms?
Prevent normal development into reproducing adults
What are the five steps of prezygotic isolating mechanisms?
- Ecological
- Behavioral
- Temporal
- Mechanical
- Prevention of gamete fusion
What is ecological isolation?
Populations are isolated because they use different portions of the environment. They occupy different habitats and rarely encounter each other
What is behavioral isolation?
Species differ in mating rituals and therefore do not interbreed. Can be visual, sound, chemical, or electrical.
What is temporal isolation?
Species reproduce in different seasons or at different times of day.
What is mechanical isolation?
Structural differences between species prevent mating
What is prevention of gamete fusion?
Gametes of one species function poorly with the gametes of another or within the reproductive tract of another species.
