About time too. From Jim Daley at The Scientist:
The biological species concept, proposed by Ernst Mayr in the 1940s, defines a species as a group of individuals that can make fertile offspring only with one another, a notion he termed “reproductive isolation.”
But that idea doesn’t jibe with Detwiler’s observations of monkeys in Gombe. By analyzing the mitochondrial DNA from epithelial cells found in 144 monkeys’ poop, she showed that red-tailed guenons (Cercopithecus ascanius) and blue guenons (C. mitis) have been mating and producing hybrid offspring for many generations. Using the sequencing data, she found that all of the monkeys in the park—hybrids, red-tails, and blues alike—can trace their ancestry back to an original group of female red-tailed guenons that mated with male blue guenons that arrived in the park several hundred and possibly even thousands of years ago. They have been mating and producing hybrid offspring, which in turn have mated with one another and with other guenons, since then.
Are organisms like the red-tailed and blue guenons distinct species, subspecies, or a single species, then? “I think we really need to think about the meaning of . . . variation,” especially with the availability of molecular biology techniques to study the genetic differences between species, says Glenn. Hybridization events challenge the idea of discrete species, which may exist on more of a kind of biological “smear” instead. “It’s not a clean continuum.” More.
“Species” is one of those mysterious religious concepts around which Darwinism is built, as in On the Origin of Species and the writings of twentieth-century theologians like Ernst Mayr. Unlike concepts in science, it need not be precise, and it certainly is not. Study of the mass of arbitrary, idiosyncratic classifications seems mainly to be a way of continuing to do homage to Darwin’s view of life.
A scientific concept of species might be possible, of course, maybe using genome mapping. But the results would probably look very different from what we see now.
The next step, we are told, is to determine how well the hybrids are reproducing. At least the problem is beginning to be discussed in a more focused way.
Note: We covered this finding here, as it relates to sexual selection theory: See K.M. Detwiler, “Mitochondrial DNA analyses of Cercopithecus monkeys reveal a localized hybrid origin for C. mitis doggetti in Gombe National Park, Tanzania,” Int J Primatol, doi:10.1007/s1076, 2018. The article is open access.
See also: Sixth mass extinction, but no news on defining “species”?
Researchers: Paleontologists are naming too many species
Once again: The pygmy marmoset is two “species”
Also: Elephant family tree needs a rethink?
Speciation ain’t what it used to be. Neither is certainty about evolution.
New butterfly has 46 chromosomes, like a human, not the expected 68, like a close relative
DNA: Giraffes are four separate species?
More mammal species than we thought? But what defines a mammal species?
Nothing says “Darwin snob” like indifference to the mess that the entire concept of speciation is in