Female fish mate OUTSIDE their species?

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Female fish can breed a new species if they aren't choosy about who is Mr. Right — One of the new predator cichlid fish species that evolved in Lake Mweru/Ole Seehausen

Granted these are cichlids. Female fish can breed a new species, we are told,

… if they aren’t choosy about who is Mr. Right. Fish will mate with a species outside their own if the male’s coloring is attractive enough or if the female can’t see him properly, according to new research. Such ‘mistakes’ in mate choice can lead to the evolution of new species, an international team of scientists found after they analyzed the DNA of more than 400 cichlid fish…
The so-called ‘hybrid offspring’ can feed on different things to their parents and invade new habitats — like swimming into deeper areas of the lake. It is unclear whether all of the species will survive as they may compete with each other and die out.
Dr Meier said: “Our research shows that hybridisation can fuel the evolution of new species which is a very novel finding. Hybridisation has traditionally been viewed as something bad because if species hybridise they can, over time, merge into a single species and you lose biodiversity or lose the local species. The melting pot of Lake Mweru gave us a rare opportunity to study interactions between evolving new species and showed that in a new environment with lots of ecological opportunity hybridisation can be a good thing that actually increases biodiversity.”

St John’s College, University of Cambridge, “Female fish can breed a new species if they aren’t choosy about who is Mr. Right” at ScienceDaily

A “very novel” finding? It rather sounds as if “species,” as in On the Origin of Species, doesn’t matter very much at all.

Paper. (open access)

A friend took a quick look at it: “What jumps out is that they’re saying ‘species’ arise through, basically, hybridization of similar species. Seems to me we’re right back to a problem Origin of Species has: it never really defines what a species is. And, here, we’re not talking about a new “species” through gradual change, but through a sudden change brought about through hybridization. Sure seems like hybridization explains a lot. Just think of the latest from the Galapagos Islands and Darwin’s Finches. There, too, they have found, IIRC, that changes in beak size are brought about through hybridization.

“Cichlid fish are touted as evolving so fast. Well, hybridization may be the explanation for this putative fast evolution.”

But the cichlids were absolutely poster fish for natural selection acting on random mutation (Darwinism) to produce new species. If even cichlids can’t do Darwinism reliably, how important a vector in evolution can it be?

See also: A physicist looks at biology’s problem of “speciation” in humans

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Comments

Not even news. Cross species hybrids, even cross genera, have been known for ages. It probably wouldn't have surprised Darwin who thought of a species as a persistent variety rather than applying the "reproductive isolation " criteria. aarceng

The unwarranted inflation of “species” that do not even meet the loosest definition of reproductive isolation has the sole purpose of perpetuating the myth of ‘divergence of character’. ... 6. Adaptation is “fast and done”, “do or die” by necessity, unlike the supposed “slow and ongoing” ‘divergence of character’. If adaptation is not fast enough, the population simply goes extinct as many others did. The cichlids of Lake Victoria had less than 15,000 years to adapt and are as diverse if not more so than the cichlids in the other, much older African Great Lakes. But they do not need even that much time as the newer aquarium varieties obtained in a few generations show. Most likely, cichlids variants have come and gone throughout the history of all African Great Lakes in short cycles of adaptation. And that is why the cichlid biodiversity difference between a few years (Lake Victoria) and millions of years (other African Great Lakes) is unremarkable. The only remarkable fact is that cichlids have a predominantly Gondwanan distribution showing that in 180+ mil years, they did not adapt to ocean living despite their otherwise high adaptability. This clearly shows the limitations of adaptability and makes it an unlikely substitute to ‘divergence of character’. Darwin’s finches, peppered moths, bacteria, and many other also adapt fast or die as observed. And when the stimulus disappears, they revert just as quickly, and later readapt to whatever new stimulus they face or simply die out trying as confirmed. It is a very good thing ‘divergence of character’ is false, or else antibiotic resistant bacteria and other superbugs would have killed mankind by now as “evolution” falsely predicted. http://nonlin.org/divergence-of-character-myth/ Nonlin.org

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