Paul Mason and Robert Short have an article out called Neanderthal-human hybrids (I wonder what that’s about?). Here is the abstract:
Evidence from studies of nuclear and mitochondrial DNA extracted from Neanderthal fossils and humans points to fascinating hypotheses concerning the types of interbreeding that occurred between these two species. Humans and Neanderthals share a small percentage of nuclear DNA. However, humans and Neanderthals do not possess the same mitochondrial DNA. In mammals, mitochondrial DNA is exclusively maternally inherited. Taking into account an understanding of interspecific hybridity, the available data leads to the hypothesis that only male Neanderthals were able to mate with female humans. If Haldane’s Law applied to the progeny of Neanderthals and humans, then female hybrids would survive, but male hybrids would be absent, rare, or sterile. Interbreeding between male Neanderthals and female humans, as the only possible scenario, accounts for the presence of Neanderthal nuclear DNA, the scarcity of Neanderthal Y-linked genes, and the lack of mitochondrial DNA in modern human populations.
Paul Mason previously wrote about the topic over at Neuroanthroplogy, so I really don’t have much more to say on the topic, other than that I’ll get around to reading it over the next couple of days. I’m curious to see if the usual suspects in the genetics (Razib Khan), anthropological (Dienekes) and evolutionary (John Hawks) communities offer some food for thought on the topic.
For me, I’m actually more interested in Mason’s recent work on degeneracy… But that’s for a later post 😉
NPR hosts a fascinating debate on the connections between science and art and the origins of culture. The guests include the utterly bizarre mix of novelist Cormac McCarthy (The Road, No Country for old Men), filmmaker Werner Herzog (The cave of forgotten dreams, Grizzly Man), and physicist Lawrence Krauss (The physics of Star Trek). Artificial Intelligence, Neanderthal culture and our place in the universe. And a buffalo humping a woman.
4. Nuclear DNA: Forays into 3 billion base pairs
4.1 Before Vi-80
The Vindija-80 (Vi-80) specimen is an important find for geneticists: it yielded a minimally contaminated sample and provided those first steps into Neanderthal genomics.
Previously, attempts at retrieving ancient nuclear DNA sequences proved to be a notoriously difficult process, plagued with problems of degradation, contamination and chemical damage (Hofreiter et al., 2001). Researchers also need to contend with quantities of nuclear genome available: for every nuclear genome there are approximately several hundred mtDNAs (Green et al., 2008). The severity of these problems, especially contamination, is magnified through Neanderthal genetic similarity with humans (Green et al., 2006). This is troubling because nuclear DNA presents far less variability than mtDNA (Russell, 2002). As a result, huge stretches of nuclear sequences are required to find a significant number of polymorphisms (ibid). Such implications meant that discovering endogenous DNA sequences requires sifting through a large corpus of “[…] more than 70 Neanderthal bone and tooth samples from different sites in Europe and western Asia” (Green et al., 2006, pg. 331).
Continue reading “What conclusions can we draw from Neanderthal DNA pt.2”
In recent times, genetic technology has progressed sufficiently to elucidate upon some of the questions normally preserved for archaeologists. One such question concerns the fate of a group of hominins that roamed Europe and East Asia for at least 250,000 years. During this time, this species adapted and endured some of the harshest environments on offer, all while showing signs of a unique culture. Only for them to suddenly disappear from the fossil record approximately 30,000 years before present (BP) (cf. Barton et al. 2007). So, what happened to our closest evolutionary relatives, the Neanderthals?
Continue reading “What conclusions can we draw from Neanderthal DNA pt.1”
…Well, 60% of the genome at least. Not much has been said yet in regards to the nitty gritty aspects of Svante and colleagues’ findings. No doubt John Hawks and many others will offer their own perspectives over the next couple of days. If you’re interested in the immediate gist then here’s a link to the press release. Also, here is a quote from the BBC offering a succinct summary:
Continue reading “Neanderthal Genome Published”
February 12th — keep this date in mind and prepare your browser on automatic refresh because the Neanderthal genome is to be unveiled. And just to make it extra special, the date on which we’ll dip into the three billion base pairs of our extinct relative is the 200th anniversary of Charles Darwin‘s birth. Here’s a little extract from the Nature article just to peak your interest:
Comparisons with the human genome may uncover evidence of interbreeding between Neanderthals and humans, the genomes of which overlap by more than 99%. They certainly had enough time for fraternization — Homo sapiens emerged as a separate species by about 400,000 years ago, and Neanderthals became extinct just 30,000 years ago. Their last common ancestor lived about 660,000 years ago, give or take 140,000 years.
I can’t think why we wouldn’t have interbred with Neanderthals. Language of course is one possible reason, acting as a symbolic marker of group boundaries to such an extent that even cultural differences within humans would minimise gene flow (assuming language, or even a protolanguage, was around then). That said, even contemporary humans are quite willing to fuck goats (and god knows what else). So why not the Neanderthals?
N.B. If you’re not familiar with they dynamics surrounding the possibility of Neanderthals having contributed some genes to modern humans, then I strongly suggest you read John Hawks’ Neanderthal FAQ. Also, check out his sections on adaptive introgression.