Humans and Neanderthals (an extinct species of human) mated in Europe and Asia thousands of years ago to give rise to a legacy of Neanderthal DNA in modern humans, a study by the University of Edinburgh, Scotland, UK has confirmed. Scientists from the University have traced the origins of the biological ties that exist between humans and the ancient species, which are believed to have died out around 30,000 years ago.
The finding overturns a previous theory on the link between the species. It had claimed that modern Europeans and Asians are related to Neanderthals because they originated from a similar sub-population in Africa. Experts had already agreed on the fact that both groups evolved from a common ancestor in Africa before spreading to other parts of the world. Studies have shown that the two groups emerged at different times, and that Neanderthals left the African continent more than 200,000 years before humans did.
Scientists at the University and Wageningen University have shown that the genetic similarity between Neanderthals and modern human populations outside of Africa must have arisen after they began interbreeding in Europe and Asia. Researchers developed a new method to compare the competing theories on the relationship between humans and Neanderthals. They divided the genetic code of each species into a series of short blocks, which allowed them to calculate the statistical likelihood of each scenario.
As well as revealing details of the shared history of humans and Neanderthals, the method could be used to reconstruct the history of any species, including rare or extinct ones. The study, published in the journal Genetics, was funded by the National Environmental Research Council. Details at www.ed.ac.uk.
for delta people to adapt to climate change
Researchers from University of Southampton, UK, are leading an international project to understand the effect of climate change on people living in deltas in South Asia and Africa, and how they respond. The five-year DECCMA (DEltas, vulnerability and Climate Change: Migration and Adaptation) Project will focus on South, South-East and East Asia and Africa, combined they are home to 200 million people, a majority being farmers. The project will examine how people are adapting to the physical effects of climate change such as sea-level rise, alongside socio-economic pressures, including land degradation and population pressure. It aims to develop methods to predict how these four deltas may evolve over the next 50 to 100 years. Details at www.southampton.ac.uk.