Butterflies are among the most diverse and beautiful animals on the planet, with about 19,000 species living in almost every habitat and climate.
But how did they evolve, and where did they come from? These questions have puzzled scientists for decades, until now.
A new study by an international team of researchers has revealed the most comprehensive "family tree" of butterflies ever constructed, using DNA from 2,244 species representing all butterfly families and 92% of genera.
The Origin and Evolution of Butterflies
The study also used 11 rare butterfly fossils to calibrate the evolutionary tree and estimate the timing of key events in butterfly history, as per Phys.org.
The results show that butterflies originated about 101.4 million years ago, during the Cretaceous period when dinosaurs roamed the Earth.
They evolved from nocturnal moths, but unlike their ancestors, they flew during the day and fed on nectar from brightly colored flowers.
The study also traced the geographical origin of butterflies to North America, where the first butterflies diversified into several lineages that later colonized other continents.
Some of these lineages survived mass extinctions and adapted to changing climates and environments, while others went extinct or became restricted to certain regions.
Also Read: Butterflies: Extinction by 2050? Habitat Pointers, Too.
The Journey of butterflies across the Globe
The study also revealed how butterflies spread across the world over millions of years, overcoming geographical barriers and ecological challenges, as per The Conversation.
The researchers used a database of the distributions of all modern species and the plants on which they lay their eggs to reconstruct the movements of butterflies through time and space.
The study tells a dynamic story of rapid diversifications, faltering advances, and improbable dispersals.
Some groups traveled over what seem impossibly vast distances, such as crossing oceans or mountains, while others stayed in one place while continents drifted apart.
For example, the study found that one of the oldest butterfly groups, the swallowtails (Papilionidae), reached Australia about 72 million years ago, long before the continent separated from Antarctica.
One of the descendants of these early colonizers is the greater peacock awl butterfly (Allora major), which is endemic to Australia.
Another ancient group, the skippers (Hesperiidae), reached Australia about 55 million years ago, after crossing the Indian Ocean from Africa or Asia.
One of their relatives is the regent skipper butterfly (Euschemon rafflesia), which is the sole survivor of a subfamily that once had a wider distribution.
The study also found that some of the most diverse and widespread butterfly groups, such as the whites and yellows (Pieridae) and the brush-footed butterflies (Nymphalidae), originated in Eurasia and later expanded to other regions.
Some of these groups diversified rapidly in response to new ecological opportunities, such as feeding on different plants or mimicking other species for protection.
The study provides new insights into the origin and evolution of one of the most fascinating groups of animals and sheds light on their remarkable diversity and adaptations.
It also highlights the importance of conserving these delicate creatures and their habitats, as they face increasing threats from human activities and climate change.
Related article: North American Butterflies Evolved From a Common Ancestor