Washington, January 27 (ANI): In a new research, scientists have determined that Neanderthals survived for several millennia after being replaced or assimilated by anatomically modern humans everywhere else in Europe, and the last of the species died out 37,000 years ago.

The research, by Professor Joao Zilhao and colleagues, report new dating evidence for the Late Aurignacian of Portugal, an archaeological culture unquestionably associated with modern humans, that firmly constrains the age of the last Neanderthals of southern and western Iberia to no younger than some 37,000 years ago.

This new evidence therefore puts at five millennia the duration of the Iberian Neanderthal refugium, and counters speculations that Neanderthal populations could have remained in the Gibraltar area until 28,000 years ago.

These findings have important implications for the understanding of the archaic features found in the anatomy of a 30,000-year-old child unearthed at Lagar Velho, Portugal.

With the last of the Iberian Neanderthals dating to many millennia before the child was born, ‘freak’ crossbreeding between immediate ancestors drawn from distinct ‘modern’ and ‘Neanderthal’ gene pools cannot be a viable explanation.

The skeleton’s archaic features must therefore represent evolutionarily significant admixture at the time of contact, as suggested by the team who excavated and studied the fossil.

The model for the late extinction for the Neanderthals is known as the ‘Ebro Frontier’.

According to Professor Zilhao, “I believe the ‘Ebro frontier’ pattern was generated by both climatic and demographic factors, as it coincides with a period of globally milder climate during which oak and pine woodlands expanded significantly along the west facade of Iberia.”

“Population decrease and a break-up of interaction networks probably occurred as a result of the expansion of such tree-covered landscapes, favouring the creation and persistence of population refugia,” he said.

“Then, as environments opened up again for large herbivore herds and their hunters as a result of the return to colder conditions, interaction and movement across the previous boundary must have ensued, and the last of the Neanderthals underwent the same processes of assimilation or replacement that underpin their demise elsewhere in Europe five millennia earlier,” he added. (ANI)