Although we may be drawn to the titles “The Oldest Human Fossil Discovered” and “The New Human Ancestor Found,” the idea that we are on our way to digging up a real and unique moment in time and space for modern human origins is unlikely. . A new study suggests that instead of continuing to search for where and when modern human ancestors came from, the focus should be on solving other mysteries.
While the theme of human ancestors is undoubtedly fascinating, EurekAlert! notes that “the meanings of words such as ancestor and ancestor are seldom discussed in detail.” This is where the new study comes in, with a different perspective. A team of experts from the Museum of Natural History, the Francis Crick Institute and the Max Planck Institute for the Science of Human History Jena presented a new paper entitled “Origins of Modern Human Ancestors” in the journal The nature.
A single starting point will not be found in genetic or fossil records
The study explores the current understanding of modern human ancestors and how it can be traced back to the distant past, as well as some of the human ancestors found on that chronology. He also states that no specific starting point can be identified at present when we talk about modern human ancestors.
Locations of the first individuals of modern human ancestry in Eurasia, along with sites that may indicate an earlier dispersal in Asia and the Sahul (Australia-centered continental shelf). (Bergström et al. 2021 / The nature)
They write: “at present no specific moment can be identified in which modern human ancestors are limited to a limited place of birth and the first-appearing patterns of anatomical or behavioral features that are used to define Homo sapiens are consistent with a series of evolutionary histories. ”
Professor Chris Stringer, co-author of the new study and researcher at the Museum of Natural History, explained that there is not enough information to work with. He 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 about others . Over the next decade, the growing recognition of our complex origins should extend the geographical 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 called the modern human ancestor. The subject of human ancestors is carefully examined in a new study. ( Chris Stringer )
Co-author of the Pontus Skoglund study at the Francis Crick Institute continued the idea, saying:
Contrary to many people’s beliefs, genetic or fossil records have not yet revealed a definite time and place for the origin of our species. Such a moment in time, when most of our ancestors were found in a small geographical region and the features we associate with our species appeared, may not have existed. For now, it would be useful to move away from the idea of a single time and place of origin.
What should researchers look for instead?
The study identifies three significant phases in human ancestors and major questions that still surround those phases. They suggest that future research should explore these avenues instead of trying to find the evasive starting point of the human story.
The first of the three points of interest is given in the paper as “the world expansion of modern people 40 and 60 thousand years ago (ka) and their last known contacts with archaic groups such as Neanderthals and Denisovans.” A second emphasis “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 H. sapiens, Neanderthal, Denisovan and other archaic human fossils from the last 500 thousand years. Pale colors indicate uncertain but possible line assignments. b, Chronology of archaic human populations that is unlikely to have contributed to modern human ancestors. These include Homo naledi, Homo floresiensis and Homo luzonensis. (Bergström et al. 2021 / The nature)
According to study co-author Eleanor Scerri of the Pan-African Evolution Research Group at the Max Planck Institute for Human History, these major questions “refer to what mechanisms led and supported this human patchwork, with all its various ancestral threads, in time and space. Moreover, Scerri clarified that “Understanding the relationship between fractured habitats and changing human niches will undoubtedly play a key role in resolving these questions, clarifying which demographic patterns best fit the genetic and paleoanthropological record.”
What is needed to shift the focus to research on human ancestry?
To accomplish the monumental task of answering these questions, researchers note that the ancient genetic record needs to be amplified. To do this, they suggest that improvements are needed to the technology used in the recovery and screening of ancient DNA, including the ability to find ancient sedimentary genetic material. More interdisciplinary work on fossil, archaeological and genetic records is also encouraged.
Image above: A new study suggests three key phases in human ancestors for scientists to focus on future research. Source: pure adrenaline / Adobe Stock
By Alicia McDermott