While we may be drawn to the headlines of “Oldest Human Fossil Discovered” and “New Human Ancestor Found,” the idea that we are on the path to unearthing a real and unique point in time and space for modern human origins it is unlikely. A new study suggests that instead of continuing to look for where and when modern human ancestry originated, the focus should shift to solving other mysteries.
While the topic of human ancestry is certainly fascinating, EurekAlert! notes that “the meanings of words such as ancestor and ancestry are seldom discussed in detail.” This is 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 have presented a new article entitled “Origins of Modern Human Ancestry” in the journal Nature.
A single starting point will not be found in genetic or fossil records
The study explores 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 in this timeline. He also states that at present no specific starting point can be identified when we speak of modern human ancestry.
Locations of the first individuals with modern human ancestry in Eurasia, along with sites that may indicate earlier dispersal in Asia and Sahul (the continental shelf centered in Australia). (Bergström et al. 2021 / Nature)
They write: “currently no specific moment can be identified in which modern human ancestry is limited to a limited place of birth, and the patterns of the first appearance of anatomical or behavioral traits used to define Homo sapiens are consistent with a range of evolutionary histories. ”
Professor Chris Stringer, co-author of the new study and researcher at the Natural History Museum, explained that there is not enough information to work with. He said:
Some of our ancestors may have lived in groups or populations that can be identified in the fossil record, while very little is known about the others . Over the next decade, the growing recognition of our complex origins should broaden the geographical focus of paleoanthropological fieldwork to regions previously considered peripheral to our evolution, such as Central and West Africa, the Indian subcontinent, and the south. -is Asian.
This skull of Jebel Irhoud, in Morocco, is often called a modern human ancestor. The topic of human ancestry is carefully examined in a new study. ( Chris Stringer )
Co-author of the Pontus Skoglund study at the Francis Crick Institute continued the idea by stating:
Contrary to many people’s beliefs, neither the genetic record nor the fossil have so far revealed a definite time and place for the origin of our species. Such a time, when most of our ancestry was found in a small geographical 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?
The study identifies three significant phases of human ancestry and key issues that still surround these phases. They suggest that future research should explore these avenues rather than trying to find the difficult starting point of human history.
The first of the three points of interest 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 approach “is associated with a widely interpreted African origin of modern human diversity between 60 and 300 ka.” Finally, experts believe that 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 key H. sapiens, Neanderthal, Denisovan and other archaic human fossils from the last 500 thousand years. Pale colors indicate uncertain but possible lineage assignments. b, Chronology of archaic human populations that are unlikely to have contributed to modern human ancestry. These include Homo naledi, Homo floresiensis and Homo luzonensis. (Bergström et al. 2021 / Nature)
According to the co-author of the study, Eleanor Scerri, of the Pan-African Research Group on Evolution at the Max Planck Institute for the Science of Human History, these main questions “refer to what mechanisms driven and maintained this human patchwork, with all its various ancestral threads, with time and space. ”In addition, Scerri clarified that“ understanding the relationship between fractured habitats and changing human niches will undoubtedly play a key role in misunderstanding. of these issues, clarifying which demographic patterns are best suited to the genetic and paleoanthropological record. ”
What is needed to focus research on human ancestry?
To accomplish the monumental task of answering these questions, researchers point out that the ancient genetic record needs to be amplified. To do so, they suggest that improvements are needed to the technology used to recover and examine ancient DNA, including the ability to find ancient sedimentary genetic material. More interdisciplinary work on fossil, archaeological and genetic records is also encouraged.
Top image: A new study suggests three key phases in human ancestry for scientists to focus on future research. Source: adrenaline / Adobe Stock
By Alicia McDermott