While we may be drawn to the headlines of “Oldest Human Fossil Discovered” and “New Human Ancestor Found,” we are unlikely to be on the road to recovering a real single point in time and space for modern human origins. digging. A new study suggests that instead of looking further for where and when modern human lineage originated, the focus should shift to solving other mysteries.
While the topic of human ancestry is undoubtedly fascinating, EurekAlert! notes that “the meanings of words such as ancestor and lineage are rarely discussed in detail.” That’s where the new study comes in, with a different perspective. A team of experts from the Natural History Museum, the Francis Crick Institute and the Max Planck Institute for the Science of Human History Jena has presented a new paper entitled ‘Origins of modern human ancestry’ in the journal Nature
No starting point will be found in the genetic or fossil records
The study examines the current understanding of modern human ancestry and how it can be traced back to the distant past, as well as some of the human ancestors found on that timeline. It also claims that no specific starting point can currently be identified when talking about modern human ancestry.
Locations of early individuals with modern human ancestors in Eurasia, along with locations that may indicate earlier distribution in Asia and the Sahul (the continental shelf centered on Australia). (Bergström et al. 2021 / Nature
They write: ‘No specific time point can be currently identified when modern human ancestry was limited to a limited place of birth, and that patterns of the first appearance of anatomical or behavioral features used to define Homo sapiens are consistent with a range of evolutionary histories. ”
Professor Chris Stringer, a co-author of the new study and a researcher at the Natural History Museum, explained that there just isn’t enough information to work with. He 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 considered peripheral to our evolution, such as Central and West Africa, the Indian Subcontinent and Southeast Asia.
This skull from Jebel Irhoud in Morocco is often referred to as a modern human ancestor. The topic of human ancestry is carefully explored in a new study. Chris Stringer
Study co-author Pontus Skoglund of The Francis Crick Institute continued the idea, stating:
Contrary to popular belief, neither the genetic nor the fossil record has yet revealed a defined 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.
What should researchers look for instead?
The study identifies three major stages in human lineage and important questions that still surround these stages. They suggest that future research should explore these avenues rather than trying to find the elusive starting point of the human story.
The first of the three concerns is given in the paper as “the global expansion of modern humans between 40 and 60 thousand years ago (ka) and their last known contacts with archaic groups such as Neanderthals and Denisovans.” A second focus “relates to a broadly understood African origin of modern human diversity between 60 and 300 ka.” Finally, the experts believe there should be more interest in “the complex separation of modern human ancestors from archaic human groups from 0.3 to 1 million years ago.”
a, Locations of the major H. sapiens, Neanderthal, Denisovan and other archaic human fossils from the past 500 thousand years. Pale colors indicate uncertain but possible parentage assignments. b, Chronology of archaic human populations that probably did not contribute to modern human ancestry. These include Homo naledi, Homo floresiensis, and Homo luzonensis. (Bergström et al. 2021 / Nature
According to study co-author Eleanor Scerri of the Pan-African Evolution Research Group at the Max Planck Institute for the Science of Human History, ‘these important questions have to do with what mechanisms this human patchwork quilt, with all its various ancestral threads , have driven and sustained, in time and space. Scerri further clarified that “Understanding the relationship between fractured habitats and changing human niches will undoubtedly play a key role in unraveling these questions, clarifying which demographic patterns best fit the genetic and paleoanthropological data.”
What does it take to shift the focus of research on human ancestors?
To accomplish the monumental task of answering these questions, the researchers note that the ancient genetic record must be strengthened. To do this, they suggest that improvements are needed to the technology used in the retrieval and screening of ancient DNA, including the ability to find sedimentary ancient genetic material. More interdisciplinary work on the fossil, archaeological and genetic archives is also encouraged.
Top image: A new study suggests three major stages in human lineage that scientists can focus on for future research. Source: pure adrenaline / Adobe Stock
By Alicia McDermott