Convergent evolution is a curious feature of evolution which is well known to biologists.
The term convergence is used when natural selection leads to acquisition of similar structures or abilities within lines that have evolved differently, but have been subject to similar environmental conditions.
One of the best known examples is the development of the wing for flying in birds, in bats (mammals), and pterosaurs.
Homologous wings of the pterosaur (1), bat (2), and bird (3) are the consequence of convergent evolution. © John Romanes, public domain