What is the name of evolution in which unrelated organisms independently develop similar traits?

Convergent evolution occurs when unrelated organisms independently develop similar traits.

Similar environments or ecological challenges can favor similar solutions. For example, sharks and dolphins both have streamlined bodies and dorsal fins, but sharks are fish while dolphins are mammals. Their comparable shapes evolved separately because efficient swimming imposes similar physical demands.

Convergent traits are called analogous structures when they perform similar functions without being inherited from the same recent ancestral structure. This differs from homologous structures, such as the forelimbs of humans, bats, and whales, which share deep evolutionary ancestry even though their functions differ.

Convergence does not mean the organisms become closely related. It shows that natural selection can repeatedly produce similar adaptations under similar conditions. Molecular evidence and fossil histories help scientists distinguish independently evolved similarities from inherited ones.