Modern humans interbred with Neanderthals 100,000 years ago

Ancient DNA from Altai Neanderthal female is first evidence of modern human contribution to Neanderthal genome

Ever since the first draft of the Neanderthal genome was published in 2010, it has been known that Neanderthals interbred with modern humans and it is now believed that around twenty percent of their genome survives in the present-day population. Subsequent work revealed the existence of a new human species in the Russian Altai, the Denisovans, and that parts of their genome also survive in the present-day population. It has also been established that the Altai Denisovans also interbred with Neanderthals in the region and with another as yet unidentified archaic species (probably Homo erectus). What has hitherto been absent up is evidence of gene flow from early modern humans into archaic genomes. Continue reading

Advertisements

Flores ‘hobbits’ arose from an archaic human species

Study confirms that Flores hominins are not Homo sapiens  

Since their headline-making discovery in 2003, the diminutive hominins from the Indonesian island of Flores have been generally accepted to be a distinctive human species, Homo floresiensis. Popularly referred to as ‘hobbits’, they are widely believed that they owe their small size to a phenomenon known as ‘insular dwarfism’. In the absence of dangerous predators and in a habitat where food is scarce, it was suggested that they ‘downsized’ from their ancestral condition as evolution favoured smaller, less ‘gas-guzzling’ individuals. The ancestral species is often claimed to be Homo erectus, but claims have also been made for more primitive hominins such as Homo habilis or even Australopithecus. Continue reading

Adverse effects of interbreeding with Neanderthals

Not all ‘imported’ genes were beneficial

Interbreeding with Neanderthals and Denisovans is believed to have introduced many beneficial genes into the modern genome, helping the immune systems of early modern humans to fight pathogens to which they had not previously been exposed. Other ‘imported’ genes include those involved with the production of keratin, a protein that is used in skin, hair and nails, and in East Asian populations, many genes involved with protection from the sun’s UV rays are of Neanderthal origin. It is likely that the transfer of these genes helped early modern humans to adapt to conditions away from their African homeland. Continue reading

Milner Hall yields first hominin fossils

Fossils recovered at ‘Cradle of Humankind’ site

Sterkfontein is a set of limestone caves near Krugersdorp, South Africa. It is one of the most important hominin fossil-bearing sites in the world and finds include the female australopithecine Mrs Ples, discovered in 1947 and recently voted No.95 in a list of 100 Great South Africans. Sterkfontein has yielded stone tools in addition to hominin fossils and it is now part of the Cradle of Humankind, a World Heritage Site named by UNESCO in 1999. Most of the finds have been made in Members 4 and 5 of the cave’s sedimentary sequence, but rather less well known is the large underground chamber known as Milner Hall. Continue reading