SPECIATION AND REPRODUCTIVE
ISOLATION MECHANISMS
Describe the formation of a new species due to geographical barrier and
reproductive isolation mechanisms
Speciation
• If population of the same species become separated by
geographical barrier(river, mountain, lake)
• There is no gene flow between these population
• Since each population may be exposed t different environmental
conditions
• Natural selection occur independently in each population
• Such that these populations become very different from each other
genotypically and even if they won’t interbreed
• They have become different species
Reproductive isolation mechanism
• Breeding in different times of the year
• One species is fertile while the other is not
• Species specific courtship behaviour
• Courtship behaviour of another species will not attract other
species
• Adaptation to different pollinators
• Pollinators of another species is not adapted to pollinator of
another species
• Infertile offspring
• A new species can’t form because they can’t produce a fertile
offspring
• Different genitalia
• Unsuited reproductive organ prevents mating.
ISOLATION MECHANISMS
Describe the formation of a new species due to geographical barrier and
reproductive isolation mechanisms
Speciation
• If population of the same species become separated by
geographical barrier(river, mountain, lake)
• There is no gene flow between these population
• Since each population may be exposed t different environmental
conditions
• Natural selection occur independently in each population
• Such that these populations become very different from each other
genotypically and even if they won’t interbreed
• They have become different species
Reproductive isolation mechanism
• Breeding in different times of the year
• One species is fertile while the other is not
• Species specific courtship behaviour
• Courtship behaviour of another species will not attract other
species
• Adaptation to different pollinators
• Pollinators of another species is not adapted to pollinator of
another species
• Infertile offspring
• A new species can’t form because they can’t produce a fertile
offspring
• Different genitalia
• Unsuited reproductive organ prevents mating.
