Ancient humans, dubbed 'Denisovans', interbred with us
bbc.co.uk
bbc.co.uk
It is plain as day that when new species emerge, old species breed with one another. Evolution is not a discrete function. Homo Sapiens bred with Homo Neanderthalensis and evidence to support this has existed for a while afaik.
What's truly amazing here, but sort of goes hidden in the hype around interbreding (as seen on twitter, this article etc) is that a new species of humans, previously unknown to science, has been discovered.
that's the news story, not the boring interbreeding.
The idea of a "species" isn't terribly well defined over time anyway. Your mother is the same species as you, her mother is the same species as her, and so on. But if you keep following your family tree for far enough you'll start to find things which are clearly a different species from yourself.
From http://www.sciencedaily.com/releases/2005/02/050211082447.ht...:
Members of closely related species possess no physiological differences that would prevent them from interbreeding.
But closely related species are distinguished by subtle differences in the pulse rates of male crickets' simple courtship songs, a secondary sexual trait that plays a large role in mate attraction.
Among all species of Laupala, pulse rates of male courtship songs range from .5 to 4.2 pulses per second. Female crickets can detect these differences, says Mendelson, and they tend to hop towards the pulse rate of their own species and to reject songs sung at a different tempo.
Despite the fact that these crickets can interbreed (and produce fertile offspring, unlike when, say, a female horse and a male donkey produce an infertile mule), we consider them different species because they systematically do not breed. I recall reading about further experiments with similar crickets where scientists manipulated the pulse rates of one cricket species to be the same as the other. Mating occurred.
Formally, the issue is that interfertile "able to interbreed" is not a transitive relation – if A can breed with B, and B can breed with C, it does not follow that A can breed with C – and thus does not define an equivalence relation. A ring species is a species that exhibits a counterexample to transitivity.
To a Vulcan, there might be no essential difference between being related to a lizard and being related to your grandmother. To a human, however, the question of whether or not some other creature is your brother-in-law or merely a distant cousin is a very big deal.
Or possibly bribe you.
I'll consider it. Although it's one hell of a career, so I'll either have to think about it pretty carefully, or just accidentally find myself doing it one day without even knowing why.
Or maybe those dates are wrong; the diagram in the article seems to say that the Denisovans and the Neanderthals diverged from the human lineage at the same time. I got the dates I cited from this article from earlier this year: http://news.bbc.co.uk/2/hi/science/nature/8583254.stm
The second point means that either immediately or eventually, the descendants of the Denisovans were considered fully human. How did that happen? Were the Denisovans already considered fully "human" by the humans leaving Africa? Or were they considered lower, like dogs or cattle? What about vice-versa? The details of the interaction would be fascinating if we could learn them. The interbreeding was doubtlessly often a byproduct of violence, when women were stolen in raids, or when one band wiped out the men of another band in a war and appropriated their land, women, and property. But did it also happen through peaceful means? Were crossbreed children treated as fully "human" right away or were they treated as sub-human until a few more generations of cross-breeding allowed them to "pass?" Were the two kinds of humans similar enough to form families together and feel love and familiar affection, or was it just sheer horndoggery? Could they even learn each other's languages? Interbreeding shows that it makes sense to ask these kinds of questions.
But I'm happy to be told otherwise, that's just my knowledge as at the last update on the subject, which admittedly was a while ago.
Personally I think the 'we all came from Africa' story is a little too neat. I think parallell evolution of Homo Sapiens in separate continents leading to eventual interbreeding is a distinct possibility.
If they're genes in modern people (Melanesians), how are they any more ancient than any other genes that exist chiefly in one population subgroup?
Isn't it becoming increasingly indefensible to talk about "our own" species (or "us") when we know that all these species interbred and that their genetic material lives on in modern humans, even "anatomically modern" humans?
^^ Also what is the correct punctuation of that sentence??
Anyone else think, "Battlestar was right!"?
But we still have to deal with the issue of whether to put the question mark before or after the quote mark. Some folks insist on putting it inside, even when it obviously makes no sense, like in this case.
1. Did anyone else think "Battlestar was right"?
2. I thought "Battlestar was right."
3. I thought "Was Battlestar right?"
4. Did anyone else think "Was Battlestar right?"
Oh yes, and the relevant "rules" differ between American and British English anyway.
Did he ask the question, "Is one plus one two?"?
You should punctuate the quotation as if the quote were independent. If the quotation is a question it should contain the question mark, it's only logical. A question without a question mark is punctuated incorrectly - that's just plain simple logic.
If I tell you that my wife just asked me, "Can you grab a drink?" The question mark has to be inside the quotes otherwise it becomes my question. I didn't ask myself the question, so why is my punctuation asking it? Plus an unpunctuated quotation looks ugly to me.
Most famous example: http://en.wikipedia.org/wiki/Lascaux
But there's something in this article that sounds very hard to accept: DNA is extremely fragile, it is very hard to imagine it surviving 50 000 years, even in Siberian ice. It is even harder to imagine someone to be able to sequence the entire genome of such species. And also: how can they affirm there's no contamination from human DNA (e.g.: bones remaining from cannibalism)?
I'll wait to hear more confirmations of this story.
As for contamination issues... Nothing beats the original article when working out the odds of such a thing.