"Joy and pleasure are as real as pain and sorrow and one must learn what they have to teach. . . ." -- Sean Russell, from Gatherer of Clouds

"If you're not having fun, you're not doing it right." -- Helyn D. Goldenberg

"I love you and I'm not afraid." -- Evanescence, "My Last Breath"

“If I hear ‘not allowed’ much oftener,” said Sam, “I’m going to get angry.” -- J.R.R. Tolkien, from Lord of the Rings

Saturday, August 25, 2018

Saturday Science: On Racial Purity

"White supremacists" and other racists are in the news a lot over the past eighteen months (wonder why?). From a scientific standpoint, they're full of shit: genome mapping of individuals from various races has demonstrated that individuals from different races may be more similar than individuals from the same race. (Keep in mind that we share about 98% of our genes with chimpanzees, so how much difference is there going to be between human races?)

New findings make it even more depressing for racial purity advocates:

Denny was an inter-species love child.

Her mother was a Neanderthal, but her father was Denisovan, a distinct species of primitive human that also roamed the Eurasian continent 50,000 years ago, scientists reported Wednesday in the journal Nature.

Nicknamed by Oxford University scientists, Denisova 11 — her official name — was at least 13 when she died, for reasons unknown.

“There was earlier evidence of interbreeding between different hominin, or early human, groups,” said lead author Vivian Slon, a researcher at the Max Planck Institute for Evolutionary Anthropology.

“But this is the first time that we have found a direct, first-generation offspring,” she told AFP.

Denny’s surprising pedigree was unlocked from a bone fragment unearthed in 2012 by Russian archeologists at the Denisova Cave in the Altai Mountains of Siberia.

Analysis of the bone’s DNA left no doubt: the chromosomes were a 50-50 mix of Neanderthal and Denisovan, two distinct species of early humans that split apart between 400,000 to 500,000 years ago.

And then there's interbreeding between those groups and Homo sapiens:

But the most compelling evidence that inter-species hanky-panky in Late Pleistocene Eurasia may not have been that rare lies in the genes of contemporary humans.

About two percent of DNA in non-Africans across the globe today originate with Neanderthals, earlier studies have shown.

Denisovan remnants are also widespread, though less evenly.

“We find traces of Denisovan DNA — less than one percent — everywhere in Asia and among native Americans,” said Paabo.

“Aboriginal Australians and people in Papua New Guinea have about five percent.”

Side note: Moderns humans migrated to New Guinea and Australia about 40,000-50,000 years ago.

And another note: In classical taxonomy (the "science of naming") a species consists of a population whose members produce viable (i.e., fertile) offspring among themselves, but produce sterile offspring (is any) when they mate outside the group. Orchids, however, blow this idea out of the water: they are what's known as "genetically labile," which is a face-saving way of saying that they interbreed freely and produce fertile offspring across species -- and even genera: hobbyists have produced hybrids from up to five genera that are viable. From the findings in this article, it looks as though that genetic lability isn't confined to orchids.

So, it starts to look as though the only "racially pure" modern humans are Africans (and even there, there are traces of as yet unknown non-Homo sapiens ancestors).

Take that, David Duke.

Further reading:

On Neanderthals.

On Denisovans.

On interbreeding between archaic and modern humans.

On the genetic difference between "races".

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