Two species hybridized 200,000 years ago to create new butterfly species

Published on April 18, 2024

Researchers have shown that the Amazon butterfly is a hybrid species, resulting from the breeding of two other species nearly 200,000 years ago.

Hybridization drove the evolution of Heliconius elevatus.

The discovery, made by an international team led by scientists from the University of York and Harvard University, demonstrates that the formation of new species is more complex than previously thought.

Species are often thought of as the tips or leaves of the “tree of life.”In this model, new species are generated Formation of new species through tip division Lasting from thousands to millions of years.

However, scientists now understand that the branches of the tree of life are tangled together, with genes transferred from one species to another through occasional crosses. This could theoretically lead to the formation of new species; a process called hybrid speciation.

ten years of research

However, proving the possibility of hybrid speciation in animals is a difficult task, as scientists need to show that breeding between two species actually triggers the formation of an entirely new species that is genetically distinct from the parent.

A team of scientists, including researchers from many South American countries, has now discovered an example of a hybrid species among the brightly colored species Heliconius Amazon butterfly.

In a decade-long study, researchers have accumulated genetic and ecological evidence that the ancestors of today’s humans evolved nearly 200,000 years ago. Black snail and padalin snail Contributed part of the genome to create a unique third species, tall-capped moththese three species now coexist in the Amazon rainforest.

genetic basis

Kanchon Dasmahapatra, senior author of the study and a professor in the Department of Biology at the University of York, said: “Hybrid speciation may not be uncommon, but convincing examples of animal hybrid species are really hard to find.

“In the few examples that exist, either the so-called hybrid species has only existed for a few generations and may have been a short-lived entity, or the hybrid species does not live alongside its parent species, making it difficult to know whether it actually is a species.

Lead author Dr. Neil Rosser, a postdoctoral researcher at the University of York and now at Harvard University, has spent several years crossbreeding related species in the Amazon to reveal a variety of traits that are critical to maintaining species uniqueness. genetic basis. These traits include color pattern, wing shape, host plant preference, sexual pheromones, mate selection and flight.

unique combination

“Remarkably, we found that tall-capped moththe portions of the genome that control these important traits often originate from Black snail.

“This discovery is key to demonstrating that hybridization drives evolution tall-capped mothbecause it gives the species a unique combination of characteristics that prevents it from interbreeding with its parents.

Professor Das Mahapatra added: “As species distributions change rapidly due to human activities and climate change, the chances of hybridization or mixing between species may increase, which is of major significance.

“This increased mixing may cause more genes to move between species, in some cases causing species to be overwhelmed by genes from other species, and in other cases may lead to the formation of new hybrid species in the future.”

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