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 ancestry in the evolution of our species of Homo sapiens.
Most of us are fascinated by our lineage, and by extension the lineage of the human species. We regularly see headlines such as ‘New Human Ancestor Discovered’ or ‘New Fossil Changes Everything We Thought About Our Ancestors’, yet the meanings of words like ancestor and lineage are rarely discussed in detail. In the new paper, published in Nature, experts discuss our current understanding of how modern human ancestors around the world can be traced back to the distant past, and which ancestors it went through on our journey back in time.
Co-author-researcher at the Natural History Museum, Prof. Chris Stringer, said: “Some of our ancestors have lived in groups or populations that can be identified in the fossil record, while very little will be known about others. Over the next decade, the growing recognition of our complex origins should expand the geographic focus of paleoanthropological fieldwork to regions previously viewed as peripheral to our evolution, such as Central and West Africa, the Indian Subcontinent and Southeast Asia. “
The study identified three main stages in our lineage that are surrounded by big questions and will be boundaries in the research to come. From the global expansion of modern humans about 40-60,000 years ago and the last known contacts 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 no specific time point can be currently identified when modern human ancestry was limited to a limited place of birth, and that the known patterns of the first appearance of anatomical or behavioral features often used to define Homo sapiens fit into a series of evolutionary histories.
Co-author Pontus Skoglund of the Francis Crick Institute said: “Contrary to popular belief, so far neither the genetic nor the fossil record has revealed a specific time and place for the origin of our species. Such a moment in time, when most of our ancestors were found in a small geographic region and the traits we associate with our species appeared, may not have existed. For now, it would be helpful to move away from the idea of a single time and place of origin. “
“As a result, major emerging questions concern the mechanisms that powered and sustained this human patchwork quilt, with all its diverse ancestral threads, in time and space,” said study co-author Eleanor Scerri of the Pan-African Evolution Research. Group of the Max Planck Institute. for the science of human history. Understanding the relationship between fragmented habitats and evolving human niches will undoubtedly play a key role in unraveling these questions by clarifying which demographic patterns best fit the genetic and paleoanthropological data.
The success of direct genetic analyzes so far underscores the importance of a broader, ancient genetic record. This requires ongoing technological advancements in ancient DNA (aDNA) retrieval, biomolecular screening of fragmentary fossils to find unrecognized human material, broader searches for sedimentary aDNA, and improvements in the evolutionary information provided by ancient proteins. Interdisciplinary analysis of the growing genetic, fossil and archaeological data will no doubt reveal many new surprises about the roots of modern human lineage.
Header Image – This skull from Jebel Irhoud in Morocco is often referred to as a modern human ancestor. The significance of that lineage is discussed and unraveled in a new study by Bergstrom and colleagues. Image credit: Chris Stringer