I am very interested in both research papers and opinion articles about the last surviving Neanderthals. I would appreciate having your references. Thank you sincerely.
So, there are two somewhat different subjects here:
- papers which present the evidence that there was some interbreeding between Homo sapiens and Homo neanderthalensis based on genome sequencing (molecular biology) of modern living humans, Neanderthals and Homo sapiens alive contemporaneously with the Neanderthals. That is really what I was offering.
- Papers and articles about Neanderthal culture, cognitive capability and late history based mainly on palaeontology. This is what I think you were requesting? This woukld include findings about Neanderthals in their last outpost in the corner of the Iberian peninsula before they became extinct.
Anyway this post is focused on 1) and I might say something about 2) in another post. Prior to 1997, no-one had been able to extract and sequence ancient DNA, so what we knew about Neanderthals was based on palaeontology, comparative anatomy and so on. Although it had been suggested that there might have been interbreeding between H sapiens and H neanderthalensis, particularly in popular literature (see for example Jean M Auel’s novel Clan of rthe Cave Bear), I think it’s right to say that the scientific consensus was sceptical about the notion of interbreeding. As a very interested lay observer, I was personally very sceptical about the notion.
So the genomic story really starts in 1997 when Svante Paabo, Matthias Krings and colleagues successfully extracted and sequenced mitochondrial DNA from the first Neanderthal specimen ever discovered. They started with mitochondrial DNA because it is more robust than nuclear DNA and because it occurs in thousands of copies per cell. The conclusion (amongst others) from that work was that the Neanderthal mitochondrial genome was (and this is putting it rather crudely and simply) about five times further removed from a typical modern human mitochondrial genome than the entire natural variation in the modern mitochondrial genome. From molecular biology point of view, this confirms the palaeontological conclusion that H neanderthalensis is a species distinct from H sapiens and puts the divergence bewteen the two species at about 600,000 years ago. This supported my prejudice that there was no interbreeding.
Move on to 2006 when Svante Paabo’s team successfully extracted and sequenced a million base pairs of the Neanderthal nuclear genome. (Svante Paabo is one of the pioneers and the leading expert on the extraction and sequencing of ancient DNA). At the same time a team led by Edward Rubin sequenced a smaller part of the Neanderthal nuclear genome. I remember reading these papers when they were first published and it was a very exciting time.
By 2010, Svante Paabo’s team had refined the techniques sufficiently to publish the draft of the entire Neanderthal nuclear genome. By comparing the Neanderthal genome with that of a range of modern humans, they concluded that there was a limited quantity of interbreeding bewteen modern humans and Neanderthals in Europe, after the last migration of anatomically modern humans out of Africa. The evidence is that although modern humans largely displaced Neanderthals in Europe and the Near East, there was a limited quantity of interbreeding so that between 1% and 4% of the genome of non-African humans today derives from Neanderthals.
Svante Paabo has just written a book about the work to sequence the Neanderthal genome and what we can conclude from the work. The book is due to be published on 15th April - I am looking forward to it very much.
Here are the references (note Paabo’s name does not appear because he normally, very honourably, puts it last on papers published by his team):
Krings, M et al, 1997, Neandertal DNA Sequences and the origin of modern humans,
Cell 90: 19-30.
Krings, M et al, 1999, DNA Sequence of the mitochondrial hypervariable region II from the Neanderthal type specim
en. PNAS USA 96: 5581-5585
Green, R. E et al, 2006. Analysis of one million base pairs of Neanderthal DNA.
Nature 444: 330-336
Noonan, J.P. et al, 2006, Sequencing and analysis of Neanderthal genomic DNA.
Science 314: 1113-1118
Green, R. E., et al, 2010, A draft sequence of the Neandertal genome.
Science 328: 710-722
From the abstract in this last paper: “We show that Neandertals shared more genetic variants with present-day humans in Eurasia than with present-day humans in sub-Saharan Africa, suggesting that gene flow from Neandertals into the ancestors of non-Africans occurred before the divergence of Eurasian groups from each other.”
Thanks! I trust in the principle - don’t know who said it first - that science and faith need never contradict one another, we just don’t have all the answers as to why not. Something along those lines. You may know the exact quote I’m thinking of.