Scientists have long puzzled over why Neanderthals (closely related to Homo sapiens) went extinct around 40,000 years ago.
But a researcher has suggested that the two species may have been locked in a series of skirmishes for 100,000 years.
Neanderthals disappeared around 40,000 years ago, around the same time modern humans started migrating to the Near East and Europe.
Dr Longrich, of the University of Bath, believes that Neanderthals may have lived in Eurasia, while humans fought against them from Africa.
Battles between the two may have led to humans remaining on the continent, Dr Longrich believes.
Dr Longrich said that remains of both humans and Neanderthals show the telltale signs of battle, in an essay for The Conversation.
He added: “Clubs are fast, powerful, precise weapons – so prehistoric Homo sapiens frequently show trauma to the skull. So too do Neanderthals.”
He added that the injuries hint of species locked in long-running battles.
“Another sign of warfare is the parry fracture, a break to the lower arm caused by warding off blows,” said Dr Longrich.
“Neanderthals also show a lot of broken arms. At least one Neanderthal, from Shanidar Cave in Iraq, was impaled by a spear to the chest.
“Trauma was especially common in young Neanderthal males, as were deaths.”
Dr Longrich also believes that for tens of millennia, a stalemate reigned between the Neanderthals in Eurasia, until finally Homo sapiens gained an advantage.
“Finally, the stalemate broke, and the tide shifted. We don’t know why. It’s possible the invention of superior ranged weapons – bows, spear-throwers, throwing clubs – let lightly-built Homo sapiens harass the stocky Neanderthals from a distance using hit-and-run tactics,” he wrote.
“Or perhaps better hunting and gathering techniques let sapiens feed bigger tribes, creating numerical superiority in battle.”
Other researchers have suggested that the trump of Homo sapiens was down to an ability to master language, or to form social groups.
Research in 2018 suggested that the triumph of Homo sapiens was due to ability to adapt to all forms of weather, from hot deserts to icy mountains.
Homo sapiens were ‘jack of all trades’, or ‘generalist specialists’, who rapidly adapted to new environments, according to the researchers at Germany’s Max Planck Institute.
This meant that homo sapiens could adapt to - and thrive in - all environments, giving them a key advantage over other hominins.