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How did isolated populations on separate continents develop unique adaptations?

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Permian paleogeography — Pangea Distribution of landmasses, mountainous regions, shallow seas, and deep ocean basins near the end of the Permian Period. Included in the paleogeographic reconstruction are the locations of the interval's subduction zones.

When the supercontinent Pangea broke apart, it physically separated plant and animal populations, creating new, isolated landmasses. This geographic isolation, known as allopatry, prevented these groups from interbreeding and forced them to adapt to the specific environmental conditions of their new, smaller continents.12

Over time, these populations developed unique adaptations as they faced different climates, habitats, and ecological pressures. This process of speciation involves the splitting of a single lineage into genetically independent groups. As these populations remained separated, they underwent distinct evolutionary paths, leading to increased biodiversity across the globe.12

Additionally, when populations are small—such as when a new area is colonized by only a few individuals—genetic drift and the founder principle can further accelerate these differences by altering gene frequencies, causing the isolated groups to diverge even more significantly from their ancestral populations.34