Butterflies are one of the most beautiful and beloved insects in the world, but little is known about their origin and evolution.
Recently, scientists rebuilt the largest evolutionary butterfly tree ever, bringing new insights into the ancestors of these creatures.
The study suggests that the first butterflies evolved from ancient moths in North America about 100 million years ago.
At that time, the supercontinent was splitting and North America was divided into east and west by a strait. Butterflies originate on the western edge of this continent.
There are currently an estimated 20,000 different butterflies, and you can find them on every continent except Antarctica. Although scientists know when butterflies originated, they are still not sure which region they originated from.
Scientists led by the curator of butterflies and moths at the Florida Museum of Natural History compiled a new butterfly evolutionary tree covering 92 percent of known genera by sequencing 391 genes from more than 2,300 butterfly species from 90 countries.
The researchers compiled a publicly available database from multiple sources. They used 11 rare butterfly fossils as a criterion to ensure that the branching points of their evolutionary tree matched the branching times shown by the fossils.
The scientist said: "This is the most difficult research and requires people from all over the world to work together to complete. ”
The findings, published May 15 in the journal Nature Ecology and Evolution, suggest that butterflies evolved from nocturnal grazing ancestors about 101.4 million years ago. This places the first butterflies in the Middle Cretaceous period, contemporaneous with the dinosaurs.
Butterflies evolved and spread in South America. Some butterflies traveled to Antarctica, which was warmer at the time and maintained a connection with Australia. By the time the two continents began to separate, they had reached the northernmost tip of Australia, a process that began about 85 million years ago.
The butterfly then crossed the Bering Land Bridge that originally connected Russia to North America and reached what is now Russia 75-60 million years ago.
They then migrated to Cape Somalia in South-East Asia, the Middle East and Africa. They even reached India, then an isolated island, about 60 million years ago.
Surprisingly, the expansion of butterflies stalled at the Middle East rim for 45 million years, and did not expand to Europe for unknown reasons until about 45-30 million years ago. According to scientists, Europe now has fewer butterfly species compared to other parts of the world, reflecting this period of stagnation.
An examination of 31,456 butterfly host plant records found that the original butterflies fed on legumes. Legumes are prevalent in almost all ecosystems, but most plants lack powerful protective compounds resistant to insect consumption. Scientists believe these properties are what kept butterflies on the leguminous diet for millions of years.
Today, butterflies eat plants from multiple plant families, but most butterflies still feed on a single plant family.
About two-thirds of all living species feed on wheat and leguminous families. Surprisingly, the most recent common ancestor of legumes is about 98 million years old, about the same time as butterflies originated.
In short, the world's largest butterfly evolutionary tree allows scientists to reconstruct the evolutionary history of butterflies. Incredibly, the first butterflies evolved in what is now Central and North America, 100 million years ago.
This research provides us with a wealth of information about the evolutionary history of butterflies and moths, helping us better understand these diverse and beautiful creatures.
As we continue to learn about their history and their current habitats, we can work to preserve and preserve them so that future generations can also appreciate their beauty.