SCIENCE BOND

Until now, it was thought features of human sleep such as rapid eye movements were seen only in mammals and birds.  Now, a study of the bearded dragon - a popular pet - suggests these distinctive sleep rhythms emerged hundreds of million of years ago in a distant ancestor.  They could even have been present in dinosaurs, say scientists.  Some form of sleep has been described in everything from worms to people.  But the sleep phases of humans and birds are very distinctive, involving cycles of deep (slow-waGerman researchers recorded the brain activity of bearded dragons when they were sleeping. They found that similar to humans and other mammals, the reptiles showed cycles of eye movements and deep sleep.  However, while humans typically go through four or five 90-minute cycles of slow-wave sleep and REMs, the lizard sleep rhythm is faster and more regular, resulting in hundreds of much shorter cycles. And in lizards the activity seems to originate ...

Traces of human DNA found in a Neanderthal genome suggest that we started mixing with our now-extinct relatives 100,000 years ago.  Previously it had been thought that the two species first encountered each other when modern humans left Africa, about 60,000 years ago. The research is published in the journal Nature.  Dr Sergi Castellano, from the Max Planck Institute for Evolutionary Anthropology, in Germany, said: "It is significant for understanding the history of modern humans and Neanderthals."The ancient remains of a female Neanderthal, found in a remote cave in the Altai Mountains in Siberia, are the source of these revelations about the sex lives of our ancestors. A genetic analysis reveals that portions of human DNA lie within her genome, revealing an interspecies mingling that took place 100,000 years ago.Earlier research suggested that humans started interbreeding with our heavy-browed, stocky relatives when they migrated out of Africa and began to spread...

The sabre-toothed cat lived alongside early humans, and may have been a fearsome enemy, say scientists. Several feline teeth - and a chunk of arm bone - were uncovered at a site in Germany known for the oldest discovery of human spears. The 300,000-year-old animal fossils are described as "spectacular". Several types of sabre-toothed cat - once known as the sabre-toothed tiger - lived for over 40 million years, before becoming extinct about 12,000 years ago.The predator had enormous teeth, which it used to rip through flesh. Dr Jordi Serangeli, of the University of Tubingen, Germany, said the remains proved for the first time that the sabre-toothed cat was living in Europe alongside early humans. "We can say that the humans - and the sabre-toothed cat - were living 300,000 years ago in the same area, in the same landscape," he told. "The humans were hunters but they were not alone; they had to defend themselves from all the big carnivores."Homo...