Convergent evolution — The independent evolution of similar traits in separate lineages. It distinguishes resemblance inherited from a common ancestor from resemblance produced by different evolutionary histories.
Understanding by example
Streamlined bodies in fast-swimming animals are a familiar example. Similar outlines do not mean that fin-supporting bones, development or evolutionary relationships are identical. First define the level of the trait being compared.
Common misconceptions
Appearance alone cannot demonstrate convergence. Phylogeny, ancestral states, structure and function must be considered together. Convergence also does not mean that an animal intentionally changed because it needed to; similar gecko toes still require separate comparisons of adhesive structures and ancestry.
Related reading and sources
For species-specific context, see The Evolution of Gecko Toe Adhesion. Browse the full glossary.
Basic reference: Homology, convergence and parallelism.