Week 7- Evolution and Speciation Flashcards
The inability of a species to breed successfully with related species due to multiple differences.
Reproductive Isolation
2 types of isolation mechanisms:
*Prezygotic isolation mechanisms
*Postzygotic isolation mechanisms
Once new species arise from the parental species due to the effect of variation and natural selection, ____________________ through reproduction.
Reproductive barriers prevent the two species from exchanging genes
Thus two related species _________ and _________.
cannot mate with each other, remain distinct.
It is the means of two individuals are prevented from successful reproduction and kept genetically distinct from each other.
Role of Reproductive Isolation
The two individuals are unable to mate as they live in geographically different areas.
Ecological Isolation
Also called habitat or geographic.
Ecological Isolation
Mating is prevented because the reproductive organs mature at different times.
Seasonal Isolation
Also called temporal.
Seasonal Isolation
The songs in birds of two species or the coloration isolation of two fishes are so different that one female individual is able to recognize only the male of its species.
Ethological/Behavioral Isolation
The male and female organs for mating differ in different species and prevent their union.
Mechanical Isolation
The sperms of one species are not able to survive in the female tract of another species.
Physiological Isolation
If a zygote formed from different species is formed, it will die after some time. if not, it will die in its development.
Zygotic and Developmental
Also called hybrid inviability.
Zygotic and Developmental
A hybrid or a zygote formed from different species may lead to a normal life but cannot reproduce.
Hybrid Sterility
