Definition

Sexy archaeology (sek-see ahr-kee-ol-uh-jee) - noun

1. Any archaeology which is excitingly appealing.

2. Archaeology which surpasses the norm, whether through historical value, groundbreaking innovation or scientific process [Scientists discovered a new species of hominid? Now that is sexy archaeology!]

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Entries in Neanderthals (21)

Friday
Sep162011

News Roundup: September 16, 2011

There was a proverbial cornucopia of exciting headlines in the news this past week, I wish I had more time to jump into some excruciatingly sciencey detail.  The Ardipithicus sediba headlines alone warrant their own post.

The History of Jefferson County podcast begins recording next week.  The museum has graciously permitted me to use their name.  With the big thumbs up come the need for me to write, write, write!  I'd like to have four episodes finished by the end of the year, but with a hectic work schedule, boatloads of research and a family, that may be quite the challenge.  I'm going to make a point to document the process of creating the podcast and provide as much information as I can for those who are looking to produce a similar product.

More information soon.

In the meantime here is a roundup of this week's excitingly appealing archaeology news:

  • Neanderthals on the Iberian coast were devouring shellfish 150,000 years ago.  Archaeologists have uncovered fossil evidence that pushes the date of shellfish consumption in Europe back 100,000 years earlier than previously thought.
  • Christopher Columbus sailed west, looking for the Indies while Vasco da Gama sailed south and east. Both men made earthchanging discoveries but only one found what he was actually looking for.  This week On Point explores the epic voyages of Vasco Da Gama. 

  • Satellite images have revealed the Middle East's version of the Nazca lines.  Scientist's have speculated that the stone "wheel" shaped structures may be the remains of houses or cemeteries, but won't know for sure until they are excavated.
  • The Discovery Day Event has been added to Facebook.  Make sure you spread the word and invite all you social network friends!
  • And finally, you've hopefully all heard by now (or in 2010) about Australopithecus sediba, the exciting hominid fossil some scientists believe may be an immediate ancestor of modern humans.  With the publication of three years of research in this week's edition of the journal Science, a flood of information and debate has hit the net.  Some scientist are claiming this is a "bonafide transitional species”, others are a bit more skeptical.  NPR has a great interview with Paleoanthropologists Lee Berger and Bernard Wood regarding the find.  Make sure you listen to the complete Science Friday interview as there is a rousing speech about field exploration which I think would fit right into the hearts and minds of all archaeologists.  I know it got me excited.

 


Thursday
Jul282011

Strength in numbers

New research sheds light on why, after 300,000 years of domination, European Neanderthals abruptly disappeared.  Researchers from the University of Cambridge have discovered that modern humans coming from Africa swarmed the region, arriving with over ten times the population as the Neanderthal inhabitants.

The reasons for the relatively sudden disappearance of the European Neanderthal populations across the continent around 40,000 years ago has for long remained one of the great mysteries of human evolution.  After 300 millennia of living, and evidently flourishing, in the cold, sub–glacial environments of central and western Europe, they were rapidly replaced over all areas of the continent by new, anatomically and genetically ‘modern’ (i.e. Homo sapiens) populations who had originated and evolved in the vastly different tropical environments of Africa.

The most plausible answer to this long-debated question has now been published today, 29 July, in the journal Science by two researchers from the Department of Archaeology at Cambridge – Professor Sir Paul Mellars, Professor Emeritus of Prehistory and Human Evolution, and Jennifer French, a second-year PhD student.

By conducting a detailed statistical analysis of the archaeological evidence from the classic ‘Perigord’ region of southwestern France, which contains the largest concentration of Neanderthal and early modern human sites in Europe, they have found clear evidence that the earliest modern human populations penetrated the region in at least ten times larger numbers than those of the local Neanderthal populations already established in the same regions.  This is reflected in a sharp increase in the total number of occupied sites, much higher densities of occupation residues (i.e. stone tools and animal food remains) in the sites, and bigger areas of occupation in the sites, revealing the formation of much larger and apparently more socially integrated social groupings.

Faced with this dramatic increase in the incoming modern human population, the capacity of the local Neanderthal groups to compete for the same range of living sites, the same range of animal food supplies (principally reindeer, horse, bison and red deer), and the same scarce fuel supplies to tide the groups over the extremely harsh glacial winters, would have been massively undermined.  Additionally, almost inevitably, repeated conflicts or confrontations between the two populations would arise for occupation of the most attractive locations and richest food supplies, in which the increased numbers and more highly coordinated activities of the modern human groups would ensure their success over the Neanderthal groups.

The archaeological evidence also strongly suggests that the incoming modern groups possessed superior hunting technologies and equipment (e.g. more effective and long-range hunting spears), and probably more efficient procedures for processing and storing food supplies over the prolonged and exceptionally cold glacial winters.  They also appear to have had more wide-ranging social contacts with adjacent human groups to allow for trade and exchange of essential food supplies in times of food scarcity.

Whether the incoming modern human groups also possessed more highly developed brains and associated mental capacities than the Neanderthals remains at present a matter of intense debate.  But the sudden appearance of a wide range of complex and sophisticated art forms (including cave paintings), the large-scale production of elaborate decorative items (such as perforated stone and ivory beads, and imported sea shells), and clearly ‘symbolic’ systems of markings on bone and ivory tools – all entirely lacking among the preceding Neanderthals – strongly point to more elaborate systems of social communications among the modern groups, probably accompanied by more advanced and complex forms of language.

All of these new and more complex behavioural patterns can be shown to have developed first among the ancestral African Homo sapiens populations, at least 20,0000 to 30,000 years before their dispersal from Africa, and progressive colonisation (and replacement of earlier populations) across all regions of Europe and Asia from around 60,000 years onwards.

If, as the latest genetic evidence strongly suggests, the African Homo sapiens and European Neanderthal populations had been evolving separately for at least half a million years, then the emergence of some significant contrasts in the mental capacities of the two lineages would not be a particularly surprising development, in evolutionary terms.

Professor Sir Paul Mellars, Professor Emeritus of Prehistory and Human Evolution at the Department of Archaeology, said:  “In any event, it was clearly this range of new technological and behavioural innovations which allowed the modern human populations to invade and survive in much larger population numbers than those of the preceding Neanderthals across the whole of the European continent.  Faced with this kind of competition, the Neanderthals seem to have retreated initially into more marginal and less attractive regions of the continent and eventually – within a space of at most a few thousand years – for their populations to have declined to extinction – perhaps accelerated further by sudden climatic deterioration across the continent around 40,000 years ago.”

Whatever the precise cultural, behavioural and intellectual contrasts between the Neanderthals and intrusive modern human populations, this new study published in Science demonstrates for the first time the massive numerical supremacy of the earliest modern human populations in western Europe, compared with those of the preceding Neanderthals, and thereby largely resolves one of the most controversial and long-running debates over the rapid decline and extinction of the enigmatic Neanderthal populations.

Monday
Jul182011

Genetic research confirms that non-Africans are part Neanderthal

Some of the human X chromosome originates from Neanderthals and is found exclusively in people outside Africa, according to an international team of researchers led by Damian Labuda of the Department of Pediatrics at the University of Montreal and the CHU Sainte-Justine Research Center. The research was published in the July issue of Molecular Biology and Evolution.

"This confirms recent findings suggesting that the two populations interbred," says Dr. Labuda. His team places the timing of such intimate contacts and/or family ties early on, probably at the crossroads of the Middle East.

Neanderthals, whose ancestors left Africa about 400,000 to 800,000 years ago, evolved in what is now mainly France, Spain, Germany and Russia, and are thought to have lived until about 30,000 years ago. Meanwhile, early modern humans left Africa about 80,000 to 50,000 years ago. The question on everyone's mind has always been whether the physically stronger Neanderthals, who possessed the gene for language and may have played the flute, were a separate species or could have interbred with modern humans. The answer is yes, the two lived in close association.

"In addition, because our methods were totally independent of Neanderthal material, we can also conclude that previous results were not influenced by contaminating artifacts," adds Dr. Labuda.

Dr. Labuda and his team almost a decade ago had identified a piece of DNA (called a haplotype) in the human X chromosome that seemed different and whose origins they questioned. When the Neanderthal genome was sequenced in 2010, they quickly compared 6000 chromosomes from all parts of the world to the Neanderthal haplotype. The Neanderthal sequence was present in peoples across all continents, except for sub-Saharan Africa, and including Australia.

"There is little doubt that this haplotype is present because of mating with our ancestors and Neanderthals. This is a very nice result, and further analysis may help determine more details," says Dr. Nick Patterson, of the Broad Institute of MIT and Harvard University, a major researcher in human ancestry who was not involved in this study.

"Dr. Labuda and his colleagues were the first to identify a genetic variation in non-Africans that was likely to have come from an archaic population. This was done entirely without the Neanderthal genome sequence, but in light of the Neanderthal sequence, it is now clear that they were absolutely right!" adds Dr. David Reich, a Harvard Medical School geneticist, one of the principal researchers in the Neanderthal genome project.

So, speculates Dr. Labuda, did these exchanges contribute to our success across the world? "Variability is very important for long-term survival of a species," says Dr. Labuda. "Every addition to the genome can be enriching." An interesting match, indeed.

Provided by University of Montreal

Sunday
Jun192011

Breeding with Neanderthals helped humans go global



When the first modern humans left Africa they were ill-equipped to cope with unfamiliar diseases. But by interbreeding with the local hominins, it seems they picked up genes that protected them and helped them eventually spread across the planet.

The publication of the Neanderthal genome last year offered proof that Homo sapiens bred with Neanderthals after leaving Africa. There is also evidence that suggests they enjoyed intimate relations with other hominins including the Denisovans, a species identified last year from a Siberian fossil.

But what wasn't known is whether the interbreeding made any difference to their evolution. To find out Peter Parham of Stanford University in California took a closer look at the genes they picked up along the way.

He focused on human leukocyte antigens (HLAs), a family of about 200 genes that is essential to our immune system. It also contains some of the most variable human genes: hundreds of versions - or alleles - exist of each gene in the population, allowing our bodies to react to a huge number of disease-causing agents and adapt to new ones.

The humans that left Africa probably carried only a limited number of HLA alleles as they likely travelled in small groups. Worse, their HLAs would have been adapted to African diseases.

When Parham compared the HLA genes of people from different regions of the world with the Neanderthal and Denisovan HLAs, he found evidence that non-African humans picked up new alleles from the hominins they interbred with.

One allele, HLA-C*0702, is common in modern Europeans and Asians but never seen in Africans; Parham found it in the Neanderthal genome, suggesting it made its way into H. sapiens of non-African descent through interbreeding. HLA-A*11 had a similar story: it is mostly found in Asians and never in Africans, and Parham found it in the Denisovan genome, again suggesting its source was interbreeding outside of Africa.

Parham points out that because Neanderthals and Denisovans had lived outside Africa for over 200,000 years by the time they encountered H. sapiens, their HLAs would have been well suited to local diseases, helping to protect migrating H. sapiens too.

While only 6 per cent of the non-African modern human genome comes from other hominins, the share of HLAs acquired during interbreeding is much higher. Half of European HLA-A alleles come from other hominins, says Parham, and that figure rises to 72 per cent for people in China, and over 90 per cent for those in Papua New Guinea.

This suggests they were increasingly selected for as H. sapiens moved east. That could be because humans migrating north would have faced fewer diseases than those heading towards the tropics of south-east Asia, says Chris Stringer of the Natural History Museum in London.

From New Scientist
Friday
Apr152011

Neanderthals: Bad luck and its part in their downfall 

As our ancestors moved north out of Africa and onto the doorstep to the rest of the world, they came across their long-lost cousins: the Neanderthals. As the popular story goes, the brutish hominins were simply no match for cultured, intelligent Homo sapiens and quickly went extinct.

Maybe, but it's also possible that Neanderthals were simply unlucky and disappeared by chance, mathematicians propose.

We know that humans and Neanderthals got pretty cosy during their time together in the Middle East, 45,000 years ago. Between 1 and 4 per cent of the DNA of modern non-Africans is of Neanderthal origin, implying their ancestors must have interbred before humans moved into Europe.

The popular theory has it that humans soon displaced Neanderthals thanks to their superior skills and adaptations. But mathematicians Armando Neves at the Federal University of Minas Gerais in Belo Horizonte, Brazil, and Maurizio Serva at the University of Aquila, Italy, now say that the extinction of Neanderthals may have been down to a genetic lottery.

When two populations interbreed, one of them can go extinct simply due to the random mixing of their genes through sexual reproduction.

To find out if this could have wiped out Neanderthals, Neves and Serva modelled the populations that met in the Middle East. Using very few assumptions, they estimated the rate of interbreeding that would lead to the observed share of Neanderthal DNA.

Their results suggest that the 1 to 4 per cent genetic mix could have come about with one interbreeding every 10 to 80 generations. The time taken to reach this mix would depend on the size of the populations. But regardless of populations, Neves and Serva's model shows that low rates of interbreeding could theoretically have led to the extinction of Neanderthals through a genetic lottery.

"The observed low fraction of Neanderthal DNA could easily have arisen quite naturally even if Neanderthals weren't inferior," says Neves.

A strong point of the analysis, says anthropologist Luke Premo of the University of Washington in Pullman, is that it makes few assumptions about unknown factors, including the relative sizes of the African and Neanderthal populations at the time.

Nevertheless, says Premo, the evidence for some kind of superiority of the African group is still strong. "Humans were expanding while Neanderthals were fairly restricted to a portion of Eurasia," he says. "Given their larger population and expansion, it appears that humans were bound to win out."

From New Scientist