18.6 - Speciation Flashcards
What defines a species How new species evolve from existing species Prezygotic and postzygotic barriers that cause reproductive isolation Allopatric and sympatric speciation
What is a species?
Group of individuals capable of breeding to produce fertile offspring
What is speciation?
Process by which new species are formed
What are the main causes of speciation?
Reproductive isolation
What is genetic drift?
Random changes in allele frequencies
What is adaptive radiation?
Rapid diversification from ancestral species
What is reproductive isolation?
Inability to interbreed successfully
What is genetic isolation?
Lack of gene flow between populations
What are prezygotic barriers?
Prevent fertilization and zygote formation
What are postzygotic barriers?
Produce infertile or non-viable hybrids
What is allopatric speciation?
Geographical separation leads to speciation
What is sympatric speciation?
Speciation within the same geographical location
What are examples of prezygotic barriers?
Habitat isolation
What are examples of postzygotic barriers?
Hybrid infertility
Why is sympatric speciation less frequent?
Requires ecological or behavioral isolation in same location
