Convergent evolution

The fossil on the right-hand side of this picture is not, as comparison with the modern insect on the left might suggest, a butterfly. It is a lacewing called Oregramma illecebrosa. It and its relatives, the kalligrammatids, flew in the forests of the Jurassic and Cretaceous periods between 165m and 125m years ago, dying out 69m years before the first-known butterfly fossil. They are thus, as Conrad Labandeira of the Smithsonian Institution in Washington, DC, and his colleagues describe in the Proceedings of the Royal Society, examples of convergent evolution: the emergence in unrelated groups of similar bodies, to permit the pursuit of similar ways of life. Just as ichthyosaurs (marine reptiles contemporary with the kalligrammatids) and dolphins evolved basically the same shapes, in order to hunt fish and other sea creatures, so kalligrammatids seem to have evolved “butterfly-ness”, complete with large, scale-covered wings, eye spots to distract predators and mouth parts formed into a proboscis. They acted, Dr Labandeira thinks, as pollinators for the gymnosperm trees that preceded modern angiosperms, now the food plants of real butterflies.



Source: Science and technology http://ift.tt/20J0UPV

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