This skull of Jebel Irhoud in Morocco is often called a modern human ancestor. The meaning of descent is discussed and unraveled in a new study by Bergstrom and colleagues. Credit: Chris Stringer
Experts from the Natural History Museum, The Francis Crick Institute, and the Max Planck Institute for the Science of Human History Jena have teamed up to unravel the different meanings of origin in the evolution of our species Homo sapiens.
Most of us are fascinated by our ancestry, and by expanding the ancestry of the human species. We often see headlines like ‘Discovering new human ancestor’ or ‘New fossil changes everything we thought of our origin’, and yet the meanings of words like ancestor and origin are rarely discussed in detail. In the new article, published in Nature, experts examine our current understanding of how modern human origins around the world can be traced back to the distant past and what ancestors went through them during our journey back in time.
Co-author researcher at the Natural History Museum, Prof Chris Stringer, said: ‘Some of our ancestors will have lived in groups or populations that can be identified in the fossil record, while very little will be known of others. Over the next decade, the growing recognition of our complex origins should extend the geographic focus of paleoanthropological fieldwork to regions previously considered peripheral to our evolution, such as Central and West Africa, the Indian subcontinent, and Southeast Asia. ”
The study identified three key phases in our origins that are surrounded by key questions and what will be the boundary in future research. From the global expansion of modern humans about 40-60 thousand years ago and the last known contact with archaic groups such as the Neanderthals and Denisovans, to an African origin of modern human diversity about 60-300,000 years ago, and finally the complex separation of modern human ancestors of archaic human groups about 300,000 to 1 million years ago.
The scientists argue that at present no specific time can be identified when modern human descent was confined to a limited place of birth, and that the known patterns of the first appearance of anatomical or behavioral traits often used to define Homo sapiens fit in a variety of evolutionary histories.
Co-author Pontus Skoglund of The Francis Crick Institute said: ‘Contrary to many people’s beliefs, the genetic or fossil record has so far revealed a specific time and place for the origin of our species. Such a time, when the majority of our ancestry was found in a small geographical region and the traits we associate with our species appeared, might not exist. For now, it would be helpful to move away from the idea of a single time and place of origin. ‘
“Hereafter, big emerging questions relate to what mechanisms drove and maintained this human patchwork with all its various ancestral threads over time and space,” said co-author Eleanor Scerri of the Pan-African Evolution Research Group at the Max Planck Institute. for the Science of Human History. “Understanding the link between broken habitats and the shifting of human niches will undoubtedly play a key role in unraveling these questions, and it will make clear which demographic patterns best fit the genetic and paleoanthropological record.”
The success of direct genetic analyzes so far shows the importance of a broader, old genetic record. This will require continued technological improvements in the old days DNA (aDNA) recycling, biomolecular screening of fragmentary fossils to find unrecognizable human material, wider search for sedimentary aDNA and improvements in the evolutionary information provided by ancient proteins. Interdisciplinary analysis of the growing genetic, fossil and archaeological records will undoubtedly reveal many new surprises about the roots of modern human origin.
Reference: “Origins of modern human descent” by Anders Bergström, Chris Stringer, Mateja Hajdinjak, Eleanor ML Scerri and Pontus Skoglund, 10 February 2021, Nature.
DOI: 10.1038 / s41586-021-03244-5