Evolution: speciation through hybridization (Evolution)

by David Turell , Wednesday, November 20, 2019, 20:11 (1828 days ago) @ David Turell

A study of evolution through hybridization in butterflies:

https://www.nature.com/articles/d41586-019-03521-4?utm_source=Nature+Briefing&utm_c...

"The data allowed Grishin’s team to build an evolutionary tree detailing the relationships of all the butterflies, as well as to determine the pace at which new species formed. The team suggests that fast-diversifying groups of butterflies are those that swap genes with close relatives through interbreeding — a phenomenon that could extend to other organisms.

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"The tree also revealed that some groups of butterflies have evolved faster than others. Two of the fastest-evolving groups, commonly known as the blues and the whites, have developed highly specialized interactions with other organisms that might explain their rapid evolution, say Grishin’s team. The blues, or Polyommatinae, form symbiotic relationships with ants, whereas whites, or Pierini, have developed adaptations to feed on mustard plants that are toxic to many other insects.

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"An analysis of genes shared by multiple species also showed that these diverse groups were more likely to have acquired genes through interbreeding between species, rather than from a distant ancestor. Many of the genes that are swapped between species are thought to be involved in mate recognition and other factors that can cause species splits. Grishin says that by spreading such genes, interbreeding — rather than the gradual accrual of new mutations — could be helping to drive the evolution of butterfly species."

Comment: All this study shows is minor speciation by hybridization. There are 30 animal phyla and butterflies are a huge family with subspecies at the bottom of the tree. When we discuss speciation, what I am really referring to is a real advance to a new level with a different sort of organism. In our short time on Earth we really cannot see it and have no idea how the Cambrian Explosion can occur, which ended with 30 final phyla,shrunk from about 56 originals.