Butterfly Wings Tell a Story About Evolution
Posted on 6 January 2020
There’s no doubt butterflies carry beautiful patterns on their wings, but did you know that those markings actually tell a very interesting story about evolution?
Scientists from the Smithsonian Tropical Research Institute recently examined convergent evolution using butterflies. Convergent evolution occurs when different species develop similar features entirely independent from one another. As an example, in butterflies, this happens when particular species produce toxins to protect themselves from predators. The birds that eat those butterflies start to recognise their wing patterns and learn to steer clear of them. Then, other butterfly species evolve to have near-identical wing patterns to help guard themselves against predators, too.
Wing patterns develop thanks to a combination of genes, which are activated while the butterfly is still a caterpillar. To conduct their experiment, the scientists had to knock out one of the genes – wntA, which gives butterfly wings their distinctive patterning – to see how butterflies would evolve, and examine whether they would still end up looking the same or be totally dissimilar. Without the wntA gene, the butterflies wings developed very differently, revealing that various species of butterfly evolve in unique ways but often end up with similar wing patterns. In other words, they’re great examples of convergent evolution!