Study reveals evolutionary history, biogeographic origins of butterflies

Subject :Environment

Section: species in news

Context:

An international team of researchers sequenced 391 genes from nearly 2,300 butterfly species from 90 countries to help reconstruct a new phylogenomic tree of butterflies representing 92% of all general.

Details:

While the earlier classification was based more on butterfly morphology, the latest attempt has been based on genome sequencing.
As a result, the researchers found that at least 36 butterfly tribes (above genus in taxonomical classification) require reclassification.

Origin of butterflies:

According to a study published recently in the journal Nature Ecology and Evolution, butterflies originated in the Americas in the late Cretaceous, about 100 million years after the origin of flowering plants.
There is no adaptive reason for butterflies to originate in North America.
- It’s more of a coincidence that butterflies had their origin in North America where the closest moth relatives of the earliest butterflies were present.
While butterflies dispersed from North America to Europe relatively quickly about 75 million years ago due to the landmass then being nearly contiguous, the dispersal from North America to Asia was through colder northern regions and happened around 60 million years ago.
North America largely being a temperate region has far less diversity compared with the tropical region in South America and Asia.
Speciation is far higher in the tropics than in the temperate region.
- A suitable climate that allows butterflies to live through the year, the greater diversity of habitats, and the far higher diversity and an absolute number of plant species that serve as a source of food for butterflies serves as the main drivers for higher speciation of butterflies in the tropics.
The dispersal of butterflies never followed a single direction.
- The dispersal has been seen in both directions, which has been the case in other animal species.

Role of butterflies in the ecosystem:

They are naturally responsible for increasing the biodiversity of an ecosystem. Thus they are the indicator of a healthy environment.
Their primary role in the ecosystem is that of a pollinator.
Some species of butterflies such as monarch butterflies help in reducing air pollution by absorbing carbon dioxide from the atmosphere.