Prehistoric girl had Neanderthal and Denisovan parents

[Brian G Turner]

New Scientist reports on how a fragment of prehistoric bone found in Russia shows a direct combination of Neanderthal and Denisovan DNA - a Neanderthal mother, and Denisovan father: Prehistoric girl had parents belonging to different human species

Her DNA was almost 50:50 Neanderthal and Denisovan, arranged in a tell‑tale way. Our DNA comes in paired strands called chromosomes, one from each parent. In Denny’s case, each pair had one Neanderthal and one Denisovan chromosome, with very little mixing. She was the daughter of parents from different species.

Denny’s mitochondrial DNA, which is inherited only from mothers, is Neanderthal. Therefore, her mother was Neanderthal and her father Denisovan.

What's especially interesting about this story is that it is already (slowly!) becoming accepted that humans and Neanderthals interbred - but now we have evidence that Neaderthals and other pre-modern hominid species were interbreeding.

Denisovans remain mysterious and intriguing - we still only know of their existence through a handful of bones fragments, but their DNA exists in modern human populations across Asia (much as Neaderthal DNA is apparent in modern human populations across Europe).

Clearly the origin of modern humans is becoming increasingly complex.

 

[Stephen Palmer]

Fascinating!

 

[Matteo]

Thanks Brian. Fascinating stuff.

Regrettably I cancelled my NS subscription earlier this year (after many years) because I realised I simply had very little time to read the issues; I had a pile that was several months old. [Though this article must be one that is "open"].

To be fair, I also thought that in recent years the magazine had a greater emphasis on "medical" issues (which considering the progress, and new ideas, in that area is perhaps not surprising) and I'm not so interested in that, but I still found most issues worth reading...when I had the time!

 

[Brian G Turner]

And more detailed coverage of this now on the BBC: DNA shows cave girl was half Neanderthal

 

[Robert Zwilling]

It sounds like the cave is going to up end being a museum of real history. The links make for interesting reading. Here is an article that gives a good overview of the Denisovan Cave in 2015. I remember reading about the Denisovan tooth last year. That article said that they had probably squeezed out all the DNA information that the specimens had to offer and hopefully new excavations will lead to more discoveries. The discoveries are leading to new understandings of human nature. It is looking more and more like our personal interpretations go a long way towards building scientific hypothesis that are supposed to be explaining social situations. One can only wonder how much of what is classified as science is actually bad science fiction.

 

[Vertigo]

It sounds like the cave is going to up end being a museum of real history. The links make for interesting reading. Here is an article that gives a good overview of the Denisovan Cave in 2015. I remember reading about the Denisovan tooth last year. That article said that they had probably squeezed out all the DNA information that the specimens had to offer and hopefully new excavations will lead to more discoveries. The discoveries are leading to new understandings of human nature. It is looking more and more like our personal interpretations go a long way towards building scientific hypothesis that are supposed to be explaining social situations. One can only wonder how much of what is classified as science is actually bad science fiction.

I think this is just normal good science. We make discoveries and then put forward theories. We make new discoveries and we modify those theories based on the new evidence. This is normal. Particularly in the area of archaeology where there are always going to be inevitable gaps in the available evidence.

In this particular case I am sure there will be new discoveries in the future that will make us amend the picture that has been added to by these ones. Obviously the more incomplete the data is the more our (inevitably biased) assumptions will be employed to extrapolate the full picture. And, realistically, we can never hope in the case of archaeology to have a proven full picture at particularly for pre-historic stuff.

 

[Robert Zwilling]

I just don't feel comfortable with the assumption that the unknown ancestors always seem to be labeled as backwards, violent people prone to using illogical solutions for everyday problems. If having art is a proof of being civilized, the people from a 100,000 years ago keep rising up the ranks every time a new a piece of their art is found. Our inability to find things is never the problem. I think it's a case where people have to take themselves out of their current life experiences and look at the old world through the eyes and experiences of what it was like back then. The idea that you had to be there to appreciate the creativity of something that we now find little appreciation for, it's the same way older books get judged.

 

[BAYLOR]

I just don't feel comfortable with the assumption that the unknown ancestors always seem to be labeled as backwards, violent people prone to using illogical solutions for everyday problems. If having art is a proof of being civilized, the people from a 100,000 years ago keep rising up the ranks every time a new a piece of their art is found. Our inability to find things is never the problem. I think it's a case where people have to take themselves out of their current life experiences and look at the old world through the eyes and experiences of what it was like back then. The idea that you had to be there to appreciate the creativity of something that we now find little appreciation for, it's the same way older books get judged.

Neanderthal man had a larger brain then modern man.

 

[dask]

Neanderthal man had a larger brain then modern man.

Yeah, but how convoluted was it?

 

[BAYLOR]

Yeah, but how convoluted was it?

That is a good question and one I think we will never know the answer to.

 

[Robert Zwilling]

A lot of the choices were convoluted back then compared to what we have to decide today. Probably put really deep grooves in the brain just considering the reasonable options. When your local neighborhood Saber tooth tiger was hungry, did you feed him, stay out of his way, carry a bigger stick that day, or tell 'em to find his own meal.

 

[dask]

If you have to tell a Saber tooth tiger to find his own meal, he probably already has.

 

[Stephen Palmer]

For all those interested in the questions posed by Brian's link, can I recommend:
Thinking Big.
Neanderthals Rediscovered.
There's also the books by Richard Rudgley, of which Secrets Of The Stone Age gets my vote for the best.

 

[Robert Zwilling]

When I walk along the beach, the one part of a crab shell I am most likely to find in quantity and intact is the claw. It is rare to find an intact crab unless it just washed ashore. The top shell comes next, then what's left of the legs, finally the bottom of the shell. The claw is multi purpose but also a weapon, the strongest piece. Maybe the same could be true of the way arts and crafts and other soft cultural items traveled through time to today.

For a while 40,000 years was a point considered to be a marker of cultural advancement. Pieces of art and jewelry have been popping up that date back 60,000 to 100,000 years ago. Perhaps it suffers the same fate as the crab body, only the hardest pieces survive the trip through time unless they were carefully protected from the ravages of the environment for a long time.

The chances of finding cultural expressive work from 80,000 years ago might well be a lot more than just double the chances of finding something from 40,000 years ago. Hopefully the Denisovan Cave will continue to yield rare finds that aren't so rare from the time they originated from.

 

[Al Jackson]

The Kennis brothers reconstructions of Neolithic people is extraordinary.

 

[Joshua Jones]

Ok, I am going to get a bit controversial here for a minute. Being the definition of a species is typically considered "a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding (although it should be clarified that the offspring be viable)", wouldn't this require that Denisovans, Neanderthals, and homo sapiens be the same species? If modern humans possess genes from these other groups, their viability is certain, so it could not be argued that Denny here was sterile, much like a mule is. Doesn't the evidence, then, seem to require that Neanderthals and Denisovans be considered races of humans, rather than species of hominids? The only other recourse I see would be to alter the definition of species, and I know there is some grey area there, but it seems to fly in the face of the scientific method to redefine a category to meet prevonceived notions of relationships, rather than to adjust one's notions of relationships to match the data.

What am I missing here?

 

[Vertigo]

Ok, I am going to get a bit controversial here for a minute. Being the definition of a species is typically considered "a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding (although it should be clarified that the offspring be viable)", wouldn't this require that Denisovans, Neanderthals, and homo sapiens be the same species? If modern humans possess genes from these other groups, their viability is certain, so it could not be argued that Denny here was sterile, much like a mule is. Doesn't the evidence, then, seem to require that Neanderthals and Denisovans be considered races of humans, rather than species of hominids? The only other recourse I see would be to alter the definition of species, and I know there is some grey area there, but it seems to fly in the face of the scientific method to redefine a category to meet prevonceived notions of relationships, rather than to adjust one's notions of relationships to match the data.

What am I missing here?

I'm pretty sure you are completely correct here and I would suspect either poor reporting from journalists using the wrong terms or possibly a hangover from the time when it was thought the different species/races could not interbreed.

 

[Abernovo]

@Joshua Jones - closely related species can interbreed. For example, lions and tigers; horses, donkeys, and zebras; the Ulmus, and the Tilia, genera of trees.

Those last two, elms and lindens, each produce so many hybrids within their own genus that most of the forestry ecologists I know don't even try to identify the exact species. It's what we may be seeing with the early hominins -- a genus of very closely related species, capable of multiple hybridisations, several of which bred to create the modern Homo sapiens.

 

[Robert Zwilling]

The wording is convoluted, definitions keep changing, not everybody's on board, at the end of the day we're all the same species, just different expressions of the same thing. Its better than thinking last man standing. A question might be where are our bodies going in this continual drift of imagined genetic stability.

Journalism pushing chromosome views the other
This article is suggesting that birds and dinosaurs are not distant relatives but in the same family. The research was done by mathematical extrapolation. They both share a bigger selection of chromosomes, which enables them to adapt to change over a longer period of time. The chromosome list includes duplicates to double the number. Not everything has duplicates and some have multiples. Trying to unravel chromosome speak is worse than double talk. Is it a case of a package deal, genes, to chromosomes to genomes, where some combinations are more important than others? I'm also wondering if all chromosomes are of equal value.

 

[Joshua Jones]

I'm pretty sure you are completely correct here and I would suspect either poor reporting from journalists using the wrong terms or possibly a hangover from the time when it was thought the different species/races could not interbreed.

Could be. I tend to start with the assumption that if I am pointing out something which no one else has noticed, I am likely the one missing a key piece of information, but I am not certain what I could be missing here.

@Joshua Jones - closely related species can interbreed. For example, lions and tigers; horses, donkeys, and zebras; the Ulmus, and the Tilia, genera of trees.

Those last two, elms and lindens, each produce so many hybrids within their own genus that most of the forestry ecologists I know don't even try to identify the exact species. It's what we may be seeing with the early hominins -- a genus of very closely related species, capable of multiple hybridisations, several of which bred to create the modern Homo sapiens.

To be sure, mules, donkras, and ligers are the product of interspecies reproduction. However, I am certain that mules are sterile, and I am reasonably certain that donkras and ligers are as well, and I am under the impression that this is why donkeys, horses, and zebras are considered different species (revisiting my last post, it looks like I used the wrong terms for this. I was thinking fertile when I said viable. Sorry for the confusion there.). Regarding trees and plants in general, I am nearly wholly ignorant of this field of study, so I will have to defer to your superior knowledge on the matter. It does seem, however, that the animal kingdom is differentiated by the ability to produce viable, fertile offspring.

But, if it is true that Neanderthal and Denisovan genes are present in modern humans, it must be true that their offspring were capable of reproducing. That would seem to move them out of the relationship of horses and zebras and into the relationship of Arabian and Thoroughbred horses. So, it would seem better to think of them as prehistoric races of Homo sapiens, rather than, say, as Homo neanderthalensis or Homo sapiens neanderthalensis. Unless, of course, I am missing something, which I suspect is likely.