"...the researchers sought to reveal whether the Neandertal mtDNA pool exhibited long-term stability or drastic modification around the time of cohabitation with modern humans....;-)
Posted on 06/05/2006 1:11:24 PM PDT by PatrickHenry
By recovering and sequencing intact DNA from an especially ancient Neandertal specimen, researchers have found evidence suggesting that the genetic diversity among Neandertals was higher than previously thought. The findings also suggest that genetic diversity may have been higher in earlier Neandertal periods relative to later periods that approached the arrival of humans in Europe. Changes in genetic diversity over time are thought to reflect population events, such as low-population bottlenecks caused by disease or environmental change, as well as the influence of random genetic change. The findings are reported in the June 6th issue of Current Biology by a group of researchers including Ludovic Orlando and led by Catherine Hänni of Ecole Normale Supérieur in Lyon, France.
Neandertals were the only representatives of the genus Homo in Europe during most of the last 300,000 years, becoming extinct shortly after the arrival of modern humans on the continent around 30,000 years ago. Traces of mitochondrial DNA (mtDNA) sequences still present in fossilized bones have been used in past studies in an effort to identify and track the potential genetic legacy of Neandertals among modern Europeans. Though such genetic continuity would have been the hallmark of interbreeding between modern humans and Neandertals at the time of their European coexistence, the mtDNA sequences from the nine neandertal specimens that have been analyzed to date – and that lived around the time of the cohabitation period – do not match those found among modern humans, suggesting that little, if any, interbreeding took place.
In their new work, Dr. Hänni and colleagues now report the oldest Neandertal mtDNA sequence ever recovered. The Neandertal specimen analyzed consists in a molar of a 10-12 year-old child that lived in the Meuse valley (Scladina cave, Belgium) around 100,000 years ago. The specimen yielded 123bp of mtDNA – a very short section of DNA by modern sequencing standards, but a technical feat considering the very ancient source of tissue. The reason for choosing such an old specimen was simple: it unambiguously predates the period when Neandertals cohabited with modern humans. By comparing this sequence with already published – and considerably younger – Neandertal sequences, the researchers sought to reveal whether the Neandertal mtDNA pool exhibited long-term stability or drastic modification around the time of cohabitation with modern humans. There was a second reason to pay attention on the Scladina molar: it has only been discovered very recently. This means that all individuals who have been in contact with it are known, and their DNA could be sequenced to detect any possible contamination of the Neandertal sample by modern human DNA.
The Neandertal sequence from Scladina confirms that Neandertals and modern humans were only distant relatives – Neandertal sequences are all closer to each other than to any known human sequence. But the study also reveals that the genetic diversity of Neandertals has been underestimated. Indeed, the mtDNA from the Scladina sample is more divergent relative to modern humans than is mtDNA from recent Neandertals, suggesting that Neandertals were a more genetically diverse group than previously thought.
Most likely because modern women didn't care much for that "knock 'em over the head & drag 'em back to the cave" sort of dating scene. ;-)
But modern guys invented the "paper bag" to facilitate interbreeding attempts between them and Neandertal women. ;-)
A #3 postal canvas sack works well too.
This is what we call a SAMPLE. It's brothers and sisters and aunts and uncles and cousins would have had the same mitchondrial DNA which WOULD have been passed on.
I thought, maybe incorrectly, that Mito-DNA was passable only through the maternal line............
The Christians and the Jews were having a jamboree
The Buddhists and the Hindus joined on satellite TV
And while the Muslims went on another killing spree
The rest picked their four greatest priests
And they began to speak
They said "Lord the plague is on the world
Lord no man is free
The temples that we built to you
Have tumbled into the sea
Lord, if you won't take care of us
Won't you at least smite the Muzzies, please?"
"...the researchers sought to reveal whether the Neandertal mtDNA pool exhibited long-term stability or drastic modification around the time of cohabitation with modern humans....;-)
mtDNA is passed from a mother to both sons and daughters. But only daughters pass theirs on to the next generation.
With sons, their descendants will have the mtDNA of their mates.
More on Neanderthal genetics.
You still holding to your Cor Magnon tooth story?
Correct. So this dead child would have the same mitochondrial DNA as his/her sisters, as well as his mother's sisters' girls. All of them COULD have gone ahead and passed on their mtDNA.
And beer goggles hadn't yet been invented!
*****But modern guys invented the "paper bag" to facilitate interbreeding attempts between them and Neandertal women. ;-)*****
when did alcohol first hit the scene? =P
I'm confused. How does the MtDNA from one specimen show any level of diversity, even when compared with later samples?
(This is a legit question for you geneticists. I'm a geologist myself...)
Just keep in mind that the average Neanderthal temptress was burlier and stronger and quite possibly furrier than the average Cro-Magnon dude, so that whole "knock 'em over the head & drag 'em back to the cave" scene might've been a deal-breaker for the modern guys, too. ;^)
Randy has penned a number of great songs, hasn't he?
"Louisiana... they're trying to wash us away..."
and how could I forget "They don't know what love is...."?
Apparently not soon enough for the Neandertal "babes".
eh, I forgot to add the "Florence Nightingale Effect" explaining the mating of a few HS women with the surviving N. males they were helping...but I think you got the general (useless) drift...
Still a supposition. They might (although the evidence is against it) have interbred their way out of unique status as a species.
"Neandertals ... becoming extinct shortly after the arrival of modern humans on the continent around 30,000 years ago."
Evidence of the first muslims arriving in Europe?
They were antisocial and didn't band together well.
Also, this prevented the passing along of skills leading
to advancement, when one died all his skills died with him.
Homo Sapiens were more social and had strength of numbers
and by banding together and sharing skills, preserved them.
Don't come crying for a source either, I was there and I watched it happen. ;-)
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