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The Economist: Hybrids have “upturned” evolutionary theory


We don’t hear the word “upturned” much; it doesn’t sound as scary as “overturned.” The subject of the mostly pay walled article is is what really happened among Darwin’s finches: hybridization:

Despite this heavy inbreeding, the hybrids (two of which are pictured above) have been successful. They have carved out a niche in which they use their size and their deep beaks to exploit the large woody fruits of the Jamaican feverplant, which grows locally. They have, to all intents and purposes, become another species of Darwin finch, of which 13 were previously recognised. Though they do not yet have a Latinised scientific name, they are known to all as the “Big Bird” lineage.

Heretical thinking

This story would once have been considered deeply implausible. Evolution’s orthodox narrative does not suggest that hybridisation is how new animal species emerge. But, as genetic testing has proliferated, biologists have been confronted with an unexpected fact. Hybrids are not an evolutionary bug. They are a feature.

That knowledge is changing the way people think about evolution. The neat family trees envisaged by Charles Darwin in one of his early notebooks (see picture below) are turning into webs, and the primacy of mutation in generating the variation which natural selection then winnows is being challenged. The influx of genes accompanying hybridisation creates such variation too—and the harder people look, the more important that seems to get. Hybridisation also offers shortcuts on the long march to speciation that do not depend on natural selection at all. As the example of the Big Bird lineage shows, instead of taking millennia to emerge, a new species can appear almost overnight…

These findings muddy Darwin’s concept of speciation as a slow and gradual process. Biologists now know that in the right circumstances, and with the help of hybridisation, new species can emerge and consolidate themselves in a mere handful of generations. That is an important amendment to evolutionary theory.

How hybrids have upturned evolutionary theory” at The Economist

It wasn’t so long ago that people’s teaching contracts went unrenewed after they said stuff like this. Now it’s mainstream.

Why are various sources suddenly becoming so candid about the shortcomings of Darwinism? Is it just because they’re afraid of @MeToo and the Raging Woke?

Or have they begun to bore themselves? Think of it. Evolution is a fascinating topic. Why would someone want to spend their life thumping the tub for natural selection acting on random mutation (Darwinism) as the only magic science recognizes when the real history of life is out there waiting to be discovered?

It’ll be interesting to see who’s still thumping the tub a decade from now.

See also: At New Scientist: We must rethink the (Darwinian) theory of nature. If by “our greatest theory of nature,” the writers mean textbook Darwinism, well the new concepts they list are destroying it. What becomes of “natural selection acting on random mutation” if a variety of means of evolution are “natural,” mutations are not necessarily random, genes aren’t selfish and don’t come only from parents, and the fittest don’t necessarily survive? Just for a start…


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