About 100 million years ago, moths had a great discovery. Instead of hiding in the darkness at night, they started to fly around during the day. They found lots of beautiful flowers with yummy nectar that bees had made and this event was the starting point for evolution of butterflies!
Since 2019, scientists have used DNA to figure out exactly when butterflies started evolving. This showed that the earlier belief of bats causing the emergence of butterflies was wrong – it turns out it wasn’t that way at all!
Scientists have also found where these first butterflies cam from and what plants they ate.
To figure out some conclusions, scientists from around the world collected DNA samples from over 2,000 different butterfly species and almost all of their families. With this information they were able to create a kind of “butterfly tree of life” and study the movement and eating habits of butterflies throughout history. This all led them to find that the first butterflies first appeared in North and Central America. The results were recently published in Nature Ecology and Evolution.
The Florida Museum of Natural History’s curator of lepidoptera, Akito Kawahara, has been waiting for this project for a long time. He said it was something he dreamed about ever since visiting the American Museum of Natural History when he was a kid and seeing a picture on one of the curators’ door about butterflies. It required a lot of hard work from people all over the world to make this happen and it is the most challenging study he has ever participated in.
There are about 19,000 known butterfly species and we want to learn more about their history. To do this, we have to get data on where they live now and what plants they eat from. Unfortunately, all this data isn’t easy to find in one single spot!
“Sometimes, the information we need is in books that haven’t been put into computers yet and these are written in different languages,” Kawahara said.
The authors didn’t give up, so they decided to make a database that would be accessible and free to anyone. To do this, they copied information from books, museum collections, and some websites and put it all together in one place.
The researchers used 11 rare butterfly fossils in their analysis. Butterfly fossils are very hard to preserve because they have thin wings and tiny hairs. But these few fossils gave researchers the ability to track when certain important events of evolution happened.
The findings tell an interesting tale, full of drastic changes, stops and starts, and surprising migrations. Some species spread out to far away places while others stayed in the same spot even when everything around them like continents, mountains, and rivers kept shifting.
Butterflies are believed to have first started to appear in some parts of America which was made up of North and Central America and Russia. They were also connected to present day Mexico, but the continents weren’t actually joined together yet. And even though these continents were separated by a big body of water, the butterflies still managed to cross it without any problems.
Even though South America and Africa are close together, the butterflies didn’t fly directly there. They went to Asia first by crossing a bridge called the Bering Land Bridge. Then, they moved even further away heading to Southeast Asia, the Middle East, and Africa’s Horn. Finally, they reached India which at that time was surrounded by sea on all sides.
Amazingly, the butterflies arrived in Australia, which was still connected to Antarctica. In earlier days when the whole world was much warmer, these butterflies probably flew from Antarctica into Australia before they got split apart.
Butterflies lingered in western Asia for up to 45 million years before they decided to fly into Europe. Scientists don’t know exactly why, but its effects are still around today! Europe doesn’t have many kinds of butterflies compared to other parts of the world; the butterflies it does have usually live in places like Siberia and Asia.
After butterfly species appeared, they developed quickly and each one became closely associated with their own group of plants. By the time dinosaurs disappeared 66 million years ago, all of the same butterfly families that we have today had already arrived and were thriving.
Scientists studied how butterflies have been connected with bean plants over a very long period of time, and they found out that bean plants were actually the original host for butterflies in all types of butterfly family. So basically, this means that bean plants have a longstanding relationship with butterflies!
Bean plants and butterflies have grown closer together over time. They now rely on each other to survive. Bees, flies, hummingbirds, and even mammals help pollinate the bean plants. Meanwhile, butterflies enjoy eating from a much wider variety of plants now than before. Pamela Soltis, a professor from Florida Museum says this partnership has helped butterflies become one of the biggest groups of insects in the world.
“Butterflies and flowers have been working together ever since they started existing, and this special connection has caused lots of changes both in them – the butterflies and plants.”
Recently, scientists released a study that explains the evolution of butterflies. The study also revealed facts such as their hosts and where they are from. All this information was put together by many different people, like biologists, researchers, and experts to create this report. It was published in the Nature Ecology & Evolution journal on May 15th 2023. Hopefully, this research helps us understand more about these amazing creatures!
The research was sponsored by lots of organizations including the National Science Foundation, National Geographic Society, Research Council of Norway, Hintelmann Scientific Award for Zoology Systematics, European Research Council, Spanish Ministry of Science and Innovation, Russian Science Foundation, Japan Society for Promotion of Science, Brazilian National Council for Scientific and Technological Development and Museum of Comparative Zoology.
