Speciation
Biology: AQA GCSE Higher, topic 6.3.5
Speciation
Individuals are members of the same species if they can interbreed (breed amongst themselves) to produce fertile offspring. A scientist called Alfred Wallace proposed that new species develop as follows:
Geographical isolation
- Two populations of the same species become geographically isolated (separated).
Genetic variation
- The populations exhibit (show) genetic variation.
Natural selection
- Due to differing environments and selection pressures, natural selection (survival of the fittest) operates differently on the populations.
Genetic divergence
- This eventually leads to genetic divergence until the populations are unable to interbreed to produce fertile offspring.
- At this point, they have become two different species.
Test yourself on Speciation
Speciation
Which scientist proposed that new species form when populations become geographically isolated and genetically diverge?
What defines members of the same species?
Which factor is most likely to lead to speciation?
What are the conditions for speciation?