Allopatric speciationSimilar species - separate geographical areas

Similar species - separate geographical areas

Allopatric speciation

Geographic barriers

• Mountain ranges

Water separating land masses (for terrestrial species)

Geographic barriers

Geographic barriers

Land separating bodies of water (for aquatic, especially freshwater species)

Geographic barriersGlaciers

Geographic barriersValleys

Squirrels separated by the canyon

Adapted by becoming more camouflaged

Adapted by mimicking poisonous species

Allopatry• Gene flow• Different selective pressures• Reproductive isolation

New Zealand separated from Australia before mammals appeared

• Many bird species have changed due to geographic isolation

some species lost the ability to fly mountain ranges emerged to separate populations

of species such as wren, robin and hebe

video

• Wolfe: Allopatric speciation