Neanderthals in Europe were killed off by the advance of modern humans thousands of years earlier than previously believed, losing a competition for food and shelter, according to a scientific study published Wednesday.

The research uses advances in radiocarbon dating to revise understanding of early humans, suggesting they colonized Europe more rapidly and coexisted for a much shorter period with genetic ancestors.

Paul Mellars, professor of prehistory and human evolution at the University of Cambridge and author of the study, said Neanderthals — the species of the Homo genus that lived in Europe and western Asia from around 230,000 years ago to around 29,000 years ago — succumbed much more readily to competition.

"The two sides were competing for the same territories, the same animals and fuel supplies and occupying the same cave spaces. With that kind of competition, the Neanderthals were always going to come out as the losers," said Mellars, whose paper was published in the journal Nature.

Modern humans — those anatomically the same as people today — were also better equipped to deal with a 6 degree Celsius (11 Fahrenheit) fall in temperatures around 40,000 years ago.

"Because they had better clothing, better technology and a better mastery of fire, the humans were equipped to deal with it," Mellars said.

Mellars used the results of two recent studies of radiocarbon dating — a process of assessing age by counting radioactive decay of carbon in materials — to refine dates determined from fossils, bone fragments and other physical evidence that relates to the spread of humans.

Humans and Neanderthals, thought to have coexisted for 10,000 years across the whole of Europe, are more likely to have lived at the same time for only 6,000 years, the new study suggests.

Scientists believe the two species could have lived side by side at specific sites for periods of only about 2,000 years, but Mellars claims they would have lived in competition at each site for only 1,000 years.

Chris Stringer, human origins researcher at London's Museum of Natural History and not connected to the study, said the paper was an important step in the quest to reliably map the spread of human populations.

"This study suggests that the period of potential interaction was short, and also favors the idea that the impact of the newcomers was indeed a significant factor in the demise of the Neanderthals, something which has been disputed recently," said Stringer.

Two new studies of stratified radiocarbon in the Cariaco Basin, near Venezuela, and of radiocarbon on fossilized coral formations in the tropical Atlantic and Pacific have given scientists a better idea of the amount of carbon in the atmosphere over the last 50,000 years.

In turn, that work allows researchers to more accurately convert carbon years into calendar years, by taking into account variations in atmospheric carbon.

Mellars claims the first modern humans arrived in the Balkans from Israel around 46,000 years ago, about 3,000 years earlier than thought.

His study claims they were able to spread west to the Atlantic coast in around 2,500 to 3,000 years, about 1,000 years quicker than believed.

"What it has revealed is the interaction between modern humans and Neanderthals was much shorter, 6,000 years instead of 10,000," said William Davies, of the Center for the Archaeoloy of Human Origins, at the University of Southampton, who was not connected to the study.

"There is more work being done on the Neanderthals in Europe and I think the dates we have relating to interaction will keep getting shorter."