Amazon butterflies show how new species evolve through hybridization

If evolution was originally described as a tree with different species branching off to create new flowers, new research suggests the branches may actually be more tangled together.In “Mixed speciation driven by multisite introgression of ecological traits,” published in nature, Researchers at Harvard University have shown that hybridization between butterfly species can produce new species that are genetically distinct from both the parent species and its earlier ancestors.

In 1861, naturalist Henry Walter Bates described the brightly colored plants in a letter to Charles Darwin Heliconius Amazon butterflies “A glimpse into nature’s laboratory for creating new species.” More than 160 years later, an international research team led by biologists Neil Rosser, Fernando Seixas, James Mallet and Kanchon Dasmahapatra also focused on Heliconius Document the evolution of new species.

Researchers use whole-genome sequencing to show that a hybridization event occurred about 180,000 years ago Black snail and today’s ancestors padalin snail A third hybrid breed was produced, tall-capped moth. Although he is a descendant of mixed race, Highland H. A butterfly is a unique butterfly species with its own individual characteristics, including the caterpillar’s host plant and the adult’s male sex pheromones, color pattern, wing shape, flight and mate choice. Together, the three species now fly across vast areas of the Amazon rainforest.

“Historically hybridization was considered a bad thing and not particularly important in terms of evolution,” said Rosser, an entomology assistant at the Museum of Comparative Zoology. He worked as a postdoctoral researcher in Mallet Laboratory of Harvard University and Dasmahapatra Laboratory in York, UK. Rosser worked on the genetic map with co-first author Seixas, another postdoctoral researcher. “But genomic data show that hybridization between species is actually widespread.”

These effects may change the way we view species. “Many species are not complete units,” Rosser said. “They’re very porous, and they’re exchanging genetic material.” Historically, hybridization was thought to inhibit the creation of new species. However, the researchers say that in this case, hybridization not only occurred within these butterfly species but also drove the evolution of the new species itself.

“So evolving species are constantly exchanging genes, and the result is that it can actually trigger the evolution of entirely new lineages,” Rosser said.

“Typically, species are thought to be reproductively isolated. They are unable to produce reproductive hybrids,” said Mallette, professor of organismal and evolutionary biology and study co-author. “While there is now evidence of hybridization between species, What’s difficult to prove is that this hybridization is somehow involved in speciation: “The question is: how do you collapse two species together and get a third species from that collapse. “

The new research provides the next step in understanding how hybridization and speciation work. “In the last 10 or 15 years, there’s been a paradigm shift in the importance of hybridization and evolution,” Rosser explains..

This research has the potential to play a role in the current biodiversity crisis. Mallett said understanding basic things like “what a species is” is “very important to saving species and conservation,” especially in the Amazon. Additionally, such work may help to understand disease carriers. For example, several species of mosquitoes can carry malaria. Although these mosquitoes are closely related, “almost nothing is known about how they interact and whether they interbreed,” he noted.

International researchers include Lucie M. Queste, Bruna Cama, Ronald Mori-Pezo, Dmytro Kryvokhyzha, Michaela Nelson, Rachel Waite-Hudson, Matt Goringe, Mauro Costa, Marianne Elias, Clarisse Mendes Eleres de Figueiredo, André Victor L Freitas, Mathie Joron , Krzysztof Kozak, Gerardo Lamas, Ananda RP Martins, W. Owen McMillan, Jonathan Ready, Nicol Rueda-Muñoz, Camilo Salazar, Patricio Salazar, Stefan Schulz, Leila T. Shirai and Karina L. Silva-Brandão.