Monday, August 22, 2011
We like to think our superior brainpower means we survived while they perished. But we may not have been alive today, if it were not for the Neanderthals. Studies show that we owe much of the power of our immune system to genes we picked up from our caveman cousins.
Interbreeding with Neanderthals gave our ancestors a ready-made cocktail of DNA invaluable in fighting diseases common in northern climates, research by immunologist Peter Parham suggests. This, in turn, vastly sped up our evolution, and gave us the strength and resilience needed to populate the world.
Research released last year revealed that our ancestors couldn’t resist the charms of the Neanderthals tens of thousands of years ago. As a result, there is a little bit of Neanderthal in all of us. In some parts of the world, up to 4 per cent of people’s DNA comes from the short, stocky cavemen.
New research reveals how this DNA has benefited us. Professor Parham, of the respected Stanford University in California, focused on a family of 200-plus genes called human leukocyte antigens that are key to the workings of the immune system.
He showed that some of our HLA genes are identical to those that were found in Neanderthals. This includes one Neanderthal immune system gene called HLA-C*0702, which is also quite common in modern European and Asian populations but absent in modern Africans.
Experts believe that modern man and Neanderthals shared a common ancestor in Africa. Around 400,000 years ago, early Neanderthals left Africa and headed for Europe and Asia. However, our ancestors stayed behind and evolved into modern humans.
Professor Parham’s results could be explained by interbreeding between the two ‘tribes’ passing immunity to disease developed by the Neanderthals after they’d left Africa our way. The professor told a meeting of the Royal Society in London that this interbreeding instilled modern man with a ‘hybrid vigour’ that allowed it to go on and populate the world.
Matt Pope, a University College London expert in Neanderthal evolution told the Sunday Times that modern man benefited from the arrangement. ‘Rather than having to evolve from scratch as they moved out of Africa and into Europe and Asia, this interaction would have provided a fast-track to adapting to new environments.’
Tuesday, August 9, 2011
Some of the human X chromosome originates from Neanderthals and is found only in nonAfricans, a new study concludes.
"This confirms recent findings suggesting that the two populations interbred," said researcher Damian Labuda of the University of Montreal, whose work with colleagues is published in the July issue of the journal Molecular Biology and Evolution.
Neanderthal people, 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 has been whether the physically stronger Neanderthals, who had the gene for language and may have played the flute, were a separate species or could have interbred with modern humans.
The results show that the two lived in close association, probably early on in the Middle East, Labuda said. "In addition, because our methods were totally independent of Neanderthal material, we can also conclude that previous results were not influenced by contaminating artifacts."
Labuda and his team almost a decade ago 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 compared 6,000 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," said Nick Patterson of the Massachusetts Institute of Technology and Harvard University, a human ancestry researcher who was not involved in the new study.
"Labuda and his colleagues were the first to identify a genetic variation in nonAfricans 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," said David Reich, a Harvard Medical School geneticist, one of the principal researchers in the Neanderthal genome project.
So did these exchanges contribute to our success across the world? "Variability is very important for longterm survival of a species," said Labuda. "Every addition to the genome can be enriching."
For 60 years, George Kiprios, aka Rock 'n' Roll George, drove his beloved Holden 48-215 around the streets of Brisbane.
Regular as clockwork he cruised the city, radio blaring and wearing his trademark purple stovepipe trousers. As he and the car aged, George became a local legend, a classic character who was a constant in a city undergoing rapid change.
Rock ’n’ Roll George visited the same places at the same times, wearing the same clothes and always cruising in his uniquely customised car.
To fill in the gaps in the mystery about just who this old rock and roller really was, stories emerged around George. Fact and fiction became part of the mystique.
A new display at the Queensland Museum explores the different versions of George that have featured in the city’s collective imagination of those who knew George, as well as those new to his story.
Rock ‘n’ Roll George’s car will form the centrepiece of the display. To provide visitors with a unique opportunity to see behind the scenes and discover the intricate scientific processes involved in looking after the now-fragile vehicle, museum staff will undertake detailed conservation in the gallery.