Divergent evolution describes evolution in which one ancestral species gives rise to different forms in separate habitats.
As populations become isolated or experience different environmental pressures, natural selection, mutation, genetic drift, and limited gene flow can cause them to diverge. Over time, their anatomical traits, behaviors, and physiology may become increasingly different. If reproductive isolation evolves, the populations can become separate species.
The forelimbs of humans, bats, whales, and other tetrapods are a classic example of homologous structures: they share an underlying ancestral pattern but have been modified for different functions. Adaptive radiation is a particularly rapid and extensive form of divergence, but the two terms are not identical.
Convergent evolution is the opposite pattern in one important sense: unrelated lineages independently evolve similar traits under similar pressures.