Evolution: God speciates major changes (Introduction)

by David Turell , Friday, March 26, 2021, 19:38 (1339 days ago) @ David Turell

These birds are more like hybrids than a new species, only differing in colors and song. Is it splitting or lumping?:

https://phys.org/news/2021-03-endangered-songbird-assumptions-evolution.html

"By comparing this bird to a closely related neighbor (the Tawny-Bellied Seedeater) in the same group (the southern capuchino seedeaters), the researchers determined that genetic shuffling of existing variations, rather than new random mutations, brought this species into existence—and their own behaviors are keeping them apart.

"This species is one of only two known examples across the globe to have traveled this path, challenging the typical assumptions of how new species form.

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"The southern capuchino seedeaters are a group of recently evolved songbirds found throughout South America that is branching rapidly, with many of its species in the early stages of evolution. This family is best known for the dramatic variation with the males in terms of songs and plumage color, while the females are largely indistinguishable even to the most familiar researchers.

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"What they found is that the two birds are closely related genetically, only distinguishable by the genes involved in plumage coloration. As well, they found that the males responded most aggressively to songs and plumage variations aligning with their own species.

"This all means that the species could very well reproduce and hybridize—they just choose not to, therefore reinforcing their own reproductive barriers.

"On a broader level, though, when comparing the Iberá Seedeater to other capuchino species, the researchers found that the Iberá Seedeater shares genomic variants with other capuchinos in these regions, but the variants have been shuffled to form a unique combination, which, the researchers argue, could be an evolutionary shortcut that most likely underlies much of the diversity among the different subspecies of this family.

"'This is a really beautiful story about a process that we have never seen in quite this way before," says co-author Irby Lovette, director of the Fuller Evolutionary Biology Program at the Cornell Lab of Ornithology.

"'The classic and most common evolutionary model for new species is the accumulation of genetic mutations when those species are separated by a geographic barrier over perhaps millions of years. But here we found that genetic shuffling can happen quickly and without geographical isolation. It's almost like 'instant speciation.'"

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"'This is the clearest example in birds of how reshuffling of genetic variation can generate a brand-new species."

"The only other organism where this type of evolution has been seen, according to Turbek, is a group of fish found in Africa called the Lake Victoria cichlids.

"'It's interesting to see this mechanism operating in something as different as birds," Turbek commented."

Comment: A beautiful example of stretching/splitting the concept of species to make individual variation in color and song entirely separate species, when it is obvious they can breed if interested. True species cannot interbreed!! All the wildly different shapes, fur types and coloring don't split dogs into different species. Wild Darwinism on a rampage. I'm sure Darwin, himself, would find the same fault I do.