By comparing reconstructed areas for Neanderthals and the more modern humans during several climatic phases and projecting each niche onto the subsequent climatic phases, scientists from the University of Kansas and the French Center National de la Recherche Scientifique and l'Ecole Pratique d'Hautes Etudes determined Neanderthals could maintain their range across Europe during a period of less severe climatic conditions, the researchers said in a joint news release.

However, archaeological records indicate this didn't happen, researchers said. Their mathematical models predict the southern limit of the modern human territory near the Ebro River Valley in northern Spain shifted between periods.

Researchers conclude that Neanderthal populations occupying modern-day southern Spain were the last to survive because they avoided direct competition with Cro-Magnons, since the two populations settled in distinct territories during cold periods. The scientists added that any contact between Neanderthals and modern humans could have allowed cultural and genetic exchanges.