Berlin: The unique ability of homo sapiens to adapt to 'extreme' environments around the world, where other species such as the Neanderthals perished may have helped us become the last surviving hominins on the planet, a study has found.
Scientists from Max Planck Institute for the Science of Human History in Germany and the University of Michigan in the US reviewed datasets relating to the Middle and Late Pleistocene (300-12 thousand years ago).
The study, published in the journal Nature Human Behaviour, shows unique environmental settings and adaptations for Homo sapiens relative to previous and coexisting hominins such as Homo neanderthalensis and Homo erectus.
"Our species' ability to occupy diverse and 'extreme' settings around the world stands in stark contrast to the ecological adaptations of other hominin taxa, and may explain how our species became the last surviving hominin on the planet," researchers said.
Researchers suggest that investigations into what it means to be human should shift from attempts to uncover the earliest material traces of 'art', 'language', or technological 'complexity' towards understanding what makes our species ecologically unique.
In contrast to our ancestors and contemporary relatives, our species not only colonized a diversity of challenging environments, including deserts, tropical rainforests, high altitude settings, and the palaeoarctic, but also specialized in its adaptation to some of these extremes.
Although all hominins that make up the genus Homo are often termed 'human' in academic and public circles, this evolutionary group, which emerged in Africa around three million years ago, is highly diverse.
Some members of the genus Homo (namely Homo erectus) had made it to Spain, Georgia, China, and Indonesia by one million years ago.
Yet, existing information from fossil animals, ancient plants, and chemical methods all suggest that these groups followed and exploited environmental mosaics of forest and grassland.
It has been argued that Homo erectus and the 'Hobbit', or Homo floresiensis, used humid, resource-scarce tropical rainforest habitats in Southeast Asia from one million years ago to 100,000 and 50,000 years ago, respectively.
However, the researchers found no reliable evidence for this.
It has also been argued that our closest hominin relatives, Homo neanderthalensis or the Neanderthals were specialized to the occupation of high latitude Eurasia between 250,000 and 40,000 years ago.
The base for this includes a face shape potentially adapted to cold temperatures and a hunting focus on large animals such as woolly mammoths.
Nevertheless, a review of the evidence led the researchers to conclude that Neanderthals primarily exploited a diversity of forest and grassland habitats, and hunted a diversity of animals, from temperature northern Eurasia to the Mediterranean.
In contrast to these other members of the genus Homo, our species - Homo sapiens - had expanded to higher-elevation niches than its hominin predecessors and contemporaries by 80-50,000 years ago, and by at least 45,000 years ago was rapidly colonising a range of palaeoarctic settings and tropical rainforest conditions across Asia, Melanesia, and the Americas.