Tag Archives: Neanderthals

Neanderthals on the BBC

Since it began in 2000 Earth-Pages News has been covering the emergent science concerning the Neanderthals. To say that it has been a fertile field would be a considerable understatement, and I am certain that it will continue to be so. The first EPN item to mention them concerned the British Channel 4 TV documentary Neanderthals. In it I quoted Steve Jones FRS, former Head of the Department of Genetics, Evolution and Environment at University College London, who is always good for a humorous take on his science, and much more besides. ‘If you met an unwashed Cro Magnon dressed in a business suit on the Underground, you would probably change seats.  If you met a similarly garbed Neanderthal, you would undoubtedly change trains’. That they had the build of world-champion freestyle wrestlers, beetling brows and extremely large noses was illustrated in the programme by reconstructions based on their skeletal remains; yes, they did look  dangerous. But Jones’s theory is put to the test with a suitably attired actor made up as a Neanderthal man in new two-part series on BBC2, Neanderthals – Meet Your Ancestors (follow the link to watch the first programme – you need to create an account at BBC iPlayer and claim that you do have a British TV licence). Some commuters did give the chap a slightly worried glance, but there was not a rush for the doors. Ella Al-Shamahi, one of the presenters, even commented that some of her friends may well have actively sought a date with him! He certainly did not seem out of place in cosmopolitan London, and the same might be said for a cattle auction in rural Cumbria. On the New York subway he would undoubtedly have been ignored. Steve Jones was wrong!

An actor made-up to resemble a Neanderthal man in a business suit traveling on the London Underground. (Source: screen-grab from BBC2 Neanderthals – Meet Your Ancestors)

We now know that the majority of people who live on the planet today have Neanderthal segments in their genome. So between 80 and 30 ka ago to dally with Neanderthals and vice versa was as acceptable as it might be today, if they were around; probably more so, considering the amount of their DNA that is retained 2000 generations after the last possible contact. Most of the discoveries concerning Neanderthals that EPN has covered over the last 17 years are used by the two programmes to arrive at the best concept to date of just who Neanderthals were and what they were able to do.

The first episode focuses on the use of skeletal remains to visualise male and female Neanderthals, using digital techniques of forensic face and body reconstruction. Over several hundred thousand years their physiology had adapted to the fluctuating conditions of western Asia and Europe, including repeated cold episodes that ranged from full glacials to interstadials. They had also adapted to forest ecosystems where hunting would have relied on ambushing prey. Their build was suited to bursts on sprinting, probably faster than Usain Bolt could manage at his best. But they were not built for the kind of endurance needed by evolving modern humans in Africa to chase down prey in savannah scrub until they succumb to heat exhaustion. Interestingly, the right, upper-arm bones of male Neanderthals are more robust than those on the left, muscle attachment scars revealing that in life they developed large biceps, probably to use spears in powerful upward lunges into the underside of large prey, such as mammoths and aurochs. They were close-combat experts and carry the signs of injury that every such hunt would have risked. However, the series goes beyond reconstruction, by using the power of CGI motion-capture techniques developed for modern animated films and games. Actors perform the moves, and are morphed to accommodate Neanderthal physique and probable gait in the resulting action sequences – fearsomely and convincingly realistic. Analysis of a single complete hyoid bone (the hard component of the ‘voice box’ and ‘Adam’s Apple’) digitally inserted into reconstruction of the Neanderthal neck, and digital reconstruction of their possible vocal range results in demonstration of how close to human pronunciation they could have been, albeit with a pronounced distortion of the vowel Aah but almost indistinguishable for other vowels. Their faces were capable of much the same range of expressions as ours.

The second episode, available on BBC iPlayer after Sunday 20 May 2018, focuses on the genetic relations between us and Neanderthals. We gained both advantages and sets-back. It also uses what evidence there is to investigate just how like us they were in their social and intellectual behaviour. It seems they were doing OK in the grim climatic scenario of the run-up to the last glacial maximum, but succumbed to extinction during the ten thousand years following the permanent entry of anatomically modern humans into Europe and western Asia after 40 ka. Why did that happen? Every human outside  sub-Saharan Africa contains Neanderthal genes: on average about 2%. Yet each of us contains a different set, so that up to 70% of the full Neanderthal genome remains in humanity as a whole. Is it possible that they could be reconstructed? Crucially, should that ever be attempted it would pose a huge moral dilemma.

To read more on the evolutionary relationships between modern humans and Neanderthals click here.

A fully revised edition of Steve Drury’s book Stepping Stones: The Making of Our Home World can now be downloaded as a free eBook

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Neanderthals and Denisovans at it more often

Palaeogeneticists certainly have the bit between their teeth as DNA sequencing methods become faster and more productive and statistical methods of sequence analysis and comparison are made more powerful. Only last month I reported on the two-way breeding unearthed from the data on single-chromosome DNA extracted from Croatian and Spanish Neanderthals, as well as some of the tangible inheritance from Neanderthals found in living non-African people. Now a team of statisticians, anthropologists and genetic sequencers have applied the new approaches to the genomes of over 1500 non-Africans, including 35 living Melanesian people from Papua-New Guinea (Vernot, B. and 16 others 2016.  Excavating Neandertal and Denisovan DNA from the genomes of Melanesian individuals. Science, v. 351 doi:10.1126/science.aad9416).  Melanesians had previously shown evidence of hybridization with both Neanderthals and Denisovans. The most interesting outcome is that the analyses pointed towards yet more instances of interbreeding between ancestors of modern non-Africans and Neanderthals. Many East Asians have 3 Neanderthals in their family trees, for Europeans and South Asians the score is 2, while Melanesians show descent from one Neanderthal and one Denisovan. Moreover, it emerges that interbreeding episodes were at different times among different populations since anatomically modern humans migrated from Africa, beginning perhaps as long ago as 130 ka and recurring later, after different regional groups of AMH had proceeded on their separate ways.

English: Melanesia, a cultural and geographica...

Melanesia, a cultural and geographical area in the Pacific. (credit: Wikipedia)

A second study (Sankararaman, S. et al. 2016. The combined landscape of Denisovan and Neanderthal ancestry in modern humans. Current Biology, v. 26, p. 1-7) has teased out evidence for Denisovan ancestry among South Asians, their admixture with Melanesians after that group acquired Neanderthal forebears, and significant signs  of dwindling fertility among hybrid males.

Early 2016 has been very fertile as regards palaeoanthropology. Katherine Zink and Daniel Lieberman of Harvard University focus on the small teeth of Homo erectus and later humans, wondering if they arose following a major shift in culinary practices (Zink, K.D. & Lieberman, D.E. 2016. Impact of meat and lower Palaeolithic food processing techniques on chewing in humans. Nature, v. 531, p. 500-503). Their work is based  on experiments to discover how much chewing is needed to make it possible to swallow different uncooked foodstuffs (assuming that cooking did not arise until after 500 ka). It seems that simply introducing meat to the diet would have reduced mastication by around 13% (2 million chews) per year, with a 15% reduction in applied chewing force. Simply slicing and pounding takes out another 750 thousand annual chews and gives a 12% fall in average biting force. So, here’s a link between tools and human gnashers as well as with development of the hand. Fascinating, perhaps, but every hominin species since 7 Ma old Sahelanthropus tchadensis had far smaller canine teeth than are the norm among non-hominin living and fossil apes. Something else was going on with dentition during our evolution, which may have been a loss of the need for threatening teeth. From ‘Do that again and I’ll bite you’, to ‘Let’s chew this over’…

More on Neanderthals, Denisovans and anatomically modern humans