Biology - Convergent evolution
When similarities in body shape or parts of bodies are apparent in
organisms of different evolutionary origin, convergent evolution or
adaptive convergence is said to have taken place. For example sharks,
dolphins and ichthyosaurs (extinct aquatic reptiles) resemble each other.
The Australian echidna, African aardvark, South American anteater and the
Australian marsupial anteater have similar body outline, long tongue, and
powerful claws. Their anatomical resemblance is due to similar selective
pressures having operated because of their similar environments. Structures
that have similar function but are different in origin are described as
analogous. The eyes of an octopus and human, the wings of bats, birds and
insects are other examples of analogous structures; placental and marsupial
mice resemble each other.
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