Thursday 26 July 2012
http://www.washingtonpost.com/national/health-science/early-africans-mated-with-mystery-species-of-humans/2012/07/26/gJQAxFzZBX_story.html?Post+generic=%3Ftid%3Dsm_twitter_washingtonpost The human family tree just got another — mysterious — branch, an African “sister species” to the heavy-browed Neanderthals that once roamed Europe. While no fossilized bones have been found from these enigmatic people, they did leave a calling card in present-day Africans: snippets of foreign DNA. There’s only way one that genetic material could have made it into modern human populations. “Geneticists like euphemisms, but we’re talking about sex,” said Joshua Akey of the University of Washington in Seattle, whose lab identified the foreign DNA in three groups of modern Africans. These genetic leftovers do not resemble DNA from any modern-day humans. The foreign DNA also does not resemble Neanderthal DNA, which shows up in the DNA of some modern-day Europeans, Akey said. That means the newly identified DNA came from an unknown group. “We’re calling this a Neanderthal sibling species in Africa,” Akey said. He added that the interbreeding likely occurred 20,000 to 50,000 years ago, long after some modern humans had walked out of Africa to colonize Asia and Europe, and around the same time Neanderthals were waning in Europe. Akey said that present-day Europeans show no evidence of the foreign DNA, meaning the mystery people were likely confined to Africa. The find offers more evidence that for thousands of years, modern-looking humans shared the Earth with evolutionary cousins that later died out. And whenever the groups met, they did what came naturally — they bred. The once controversial idea that humans mated with other species is now widely accepted among scientists. In fact, hominid hanky-panky seems to have occurred wherever humans met others who looked kind of like them. In 2010, researchers from the Max Planck Institute for Evolutionary Anthropology in Germany announced finding Neanderthal DNA in the genomes of modern Europeans. Heavy-set people whose thick double brows, broad noses, and flat faces set them apart from modern humans, Neanderthals disappeared around 25,000 to 30,000 years ago. Another mysterious group of extinct people recently identified from a finger bone in Siberia — known as the Denisovans — also left some of their DNA in modern day Pacific Islanders. And while modern humans and the newly found “archaic” Africans might be classified as distinct species, they managed to produce viable offspring. Likewise, donkeys and horses, lions and tigers, and whales and dolphins can mate and make babies. “They had to be similar enough in appearance to anatomically modern humans that reproduction would happen,” said Akey. But with no fossils in hand, it’s impossible to say what these people looked like. It’s also impossible to say whether the matings were consensual or forced. But one thing is clear: This enigmatic group left their DNA all across Africa. The researchers found it in the forest-dwelling pygmies of central Africa and in two groups of hunter-gatherers on the other side of the continent — the Hadza and Sandawe people of Tanzania. Starting a decade ago, a team led by Sarah Tishkoff of the University of Pennsylvania drew blood from five individuals in each of the three groups. Using the latest genetic technology, Tishkoff spent $150,000 to read, or sequence, the DNA of these 15 people. Besides finding evidence of the now-extinct species, the team discovered a huge range of genetic diversity between the three groups. The human genome contains about three billions letters, or base pairs, of DNA. Before this study, scientists had found that some 40 million of these letters vary across human populations. But in the 15 Africans, Tishkoff found another three million genetic variants — a huge trove of human diversity. Among this stunning variety, Tishkoff says she has pinpointed some of the genes responsible for the short stature of the pygmies, who average less than five feet in height. She also found that immune system genes and genes for taste and smell varied wildly between the three groups — confirming Africa as the seat of the most human diversity. The research was reported Wednesday in the journal Cell. “This is very cutting-edge population genetics work,” said geneticist Spencer Wells, a National Geographic explorer. “This ‘whole genome’ analysis the team performed is really revolutionizing our understanding of human history. It’s an exciting time to be in the field, but it’s difficult to interpret all the new data.” Wells said the oldest modern human skull, found in Ethiopia, dates to 195,000 years ago. For more than 150,000 years, then, humans shared the planet with cousin species. Despite all the amorous advances, though, only one group survived — us. Akey said: “As we were conquering the world, we also conquered similar human populations that were dying out.”
http://www.telegraph.co.uk/news/worldnews/al-qaeda/9426488/The-Islamist-terror-that-links-Syria-and-Iraq.html The modern-day states of Iraq and Syria once formed the ancient kingdom of Mesopotamia. They share the same tribal culture, heritage and a lengthy border. It is hardly surprising, then, that they still have much in common. Having both been ruled by Hashemite kings following their creation as independent states in the aftermath of the First World War, they became the only Arab states to adopt the Ba’ath party’s revolutionary ideology and were renowned for their hostility to the West. While on occasion this relationship has become somewhat frayed, not least when the Iraqi dictator Saddam Hussein declared his desire to unite both regimes under his barbaric rule in the Seventies, the ties that exist between Baghdad and Damascus have ensured that such unpleasant memories are soon overcome. Now these two Arab states can boast yet another, less welcome, characteristic that binds them together: they have both become targets for al-Qaeda’s new generation of Islamist jihadists. At first glance, it appears that the bombers responsible for the recent attacks in Damascus and Baghdad were motivated by very different objectives. Related Articles In Syria, last week’s carefully executed bombing of the National Security headquarters, which killed President Bashar al-Assad’s brother-in-law, as well as the country’s defence minister, was in all probability the act of groups working for the Free Syrian Army, a mainly Sunni Muslim force that is seeking to overthrow Assad’s minority Allawite regime, which has ruled the country for more than four decades. In Baghdad, on the other hand, the recent well-coordinated series of bombings and shootings against a number of government targets in 15 different cities and towns was carried out by Iraqi Sunni extremists. Many of them are disaffected members of Saddam’s Ba’athist tyranny who are trying to force the government of Nouri al-Maliki, Iraq’s Shi’ite Muslim prime minister, to establish a more inclusive regime, one that represents the interests of the Sunni and Kurdish minorities, rather than simply feathering the nests of the majority Shi’ite Muslim population. But while the objectives of these anti-government activists may differ, there is a chilling similarity in the tactics they employ in their respective quarrels with the ruling cliques in Iraq and Syria. In both countries, the recent wave of bombings bears all the hallmarks of al-Qaeda terror cells, both in terms of their planning and the execution. Indeed, the group responsible for the Iraqi bombings, al-Qaeda in Iraq, makes no secret of its allegiance to the organisation originally founded by Osama bin Laden. In a statement issued shortly after the attacks, Abu Bakr al-Baghdadi, who claims to be the leader of the Iraqi cell, deliberately sought to link the violence in Iraq to the Sunni revolt in neighbouring Syria. According to al-Baghdadi, al-Qaeda has launched a campaign it calls “Breaking Down the Walls”, whereby it aims to overthrow the established governments in Baghdad and Damascus and replace them with regimes more in tune with the group’s strict Islamist agenda. This might seem far-fetched, particularly as al-Qaeda has already suffered one humiliating defeat in Iraq: moderate Sunni tribal leaders refused to support the terrorist group’s extremist agenda and helped US forces to defeat it by forming the “Anbar Awakening” in 2006. Iraqi Sunnis might want to see a more representative government running Baghdad, but most of them have no desire for a return of the appalling scenes of sectarian violence that devastated the country from 2006 to 2007. And yet the fact that al-Qaeda, which was effectively destroyed as an organisation in Iraq by the end of 2007, is back with a vengeance is a direct result of the violence taking place in neighbouring Syria. Even before last week’s attack on the National Security building, senior Iraqi officials had expressed concern about the existence of a number of al-Qaeda cells in the eastern city of Fallujah, which were travelling freely across the Syrian border to support the rebel cause. Now it appears that these cells are travelling in the opposite direction from Syria to Iraq, with all the potentially disastrous implications that could have for regional stability. Until now the priority of Western policy-makers has been to stop the fighting in Syria on humanitarian grounds. But a conflict that has so far claimed more than 17,000 Syrian lives could easily reach levels not seen since the worst days of Iraq’s sectarian violence – if, as now seems possible, the turbulence spreads beyond Syria’s borders. Rather than treating Syria as a humanitarian crisis, the West should see its troubles as a threat to the stability of the entire region, and act accordingly.
Monday 9 July 2012
In a discovery that could rewrite the history of the Americas, archaeologists have found a number of stone tools dating back between 19,000 and 26,000 years, and bearing remarkable similarities to those made in Europe. All of the ancient implements were discovered along the north-east coast of the USA. The tools could reassert the long dismissed and discredited claim that Europeans in the form of Christopher Columbus and his crew were the first to discover the New World. Previous discoveries of tools have only been dated back to 15,000 years ago and prompted many archaeologists and historians to question claims that stone-age man managed to migrate to North America. But the striking resemblance in the way the primitive American tools were made to European ones dating from the same period now suggests a remarkable migration took place. Adding to the weight of evidence is fresh analysis of stone knife unearthed in the US in 1971 that revealed it was made of French flint. Professor Dennis Stanford from Washington's Smithsonian Institution, and Professor Bruce Bradley from Exeter University believe that the ancient Europeans travelled to North America across an Atlantic frozen over by the Ice Age. During the height of the Ice Age, ice covered some three million square miles of the North Atlantic, providing a solid bridge between the two continents. Plentiful numbers of seal, penguins, seabirds and the now extinct great auk on the edge of the ice shelf could have provided the stone-age nomads with enough food to sustain them on their 1,500-mile walk. "Across Atlantic Ice", a book by professors Stanford and Bradley presenting the case for the trans-Atlantic trek, is published next month.