Image Caption
After some generations, the island flies become reproductively isolated from the mainland flies. Peripatric speciation has occurred.
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This image is part of a series:

Peripatric speciation (1 of 5)
Only a few fruit fly larvae survived the journey from the mainland to colonize the island.
Peripatric speciation (2 of 5)
These few survivors just by chance carry some genes that are rare in the mainland population. One of these rare genes happens to cause a slight variation in the mating…
Peripatric speciation (3 of 5)
These small differences, which are rare on the mainland, drift to fixation in the small population on the island over the course of a few generations (i.e., the entire island…