[ad_1]
Humans did not come from a single ancestral population in an area of Africa, as is often claimed. Instead, our African ancestors were diverse in form and culture and were scattered all over the continent, according to a study conducted by a Maltese archaeologist
Multiregional Evolution: The patchwork of various fossils, artifacts and environments across Africa indicates that modern humans have emerged from interactions between a set of connected populations living across the continent and whose connectivity has changed over time. Photo: Yasmine Gateau / Max Planck Institute for the Science of Human History A scientific consortium, led by Maltese archaeologist Eleanor Scerri of the University of Oxford and the University of Oxford. Max Planck Institute for the Science of Human History, discovered that human ancestors scattered throughout Africa and widely separated by a combination of diverse habitats and various environmental boundaries.
Millennia of separation have given birth to an astonishing diversity of human forms, the mixture of which eventually shaped our species
. accepted that our species is native to Africa, less attention has been paid to how man has evolved within the continent. Many have badumed that the earliest human ancestors were born as a relatively large ancestral population and exchanged genes and technologies as stone tools more or less randomly.
In an article published in Trends in Ecology and Evolution this week, is challenged, not only by the usual study of bones (anthropology), stones (archeology) and genes (genomic populations), but also by new, more detailed reconstructions of African climates and habitats over the past 300,000 years.
"Stone tools and other objects – generally referred to as material culture – exhibit remarkably grouped distributions in both space and time," said Scerri, a researcher at the University of Oxford and at the Max Planck Institute for the Science of Human History. l & # 39; study.
"Although there is a general trend towards a more sophisticated material culture, this" modernization "is obviously not coming from a region or occurring at any time."
Human fossils tell a similar story. 19659005] Researchers studied the climates and environments of Africa
"When we look at the morphology of human bones over the past 300,000 years, we see a complex "Chris Stringer, researcher at the London Natural History Museum and co-author of the study.
" As with material culture, we see a continental culture. "- general trend towards the modern human form, but different modern characteristics appear in different places at different times and some archaic features are present until recently. "
The study of genes is consistent.
"It is difficult to reconcile the genetic patterns we see in living Africans and in the DNA extracted from the bones of Africans who have lived in the last 10,000 years, with an ancestral human population," he said. said Mark Thomas, a geneticist at University College London and co-author of the study.
"We see signs of very deep reduced connectivity in the past, very old genetic lineages and levels of global diversity that a single population would struggle to maintain."
Evolutionary changes in brain shape from an elongated form to a globular form. The latter evolves within the homo sapiens line by expansion of the cerebellum and swelling of the parietal. Left: CT scan of Jebel Irhoud 1 (circa 315 000 years old, Africa); Right: Qafzeh 9 (about 95,000 years old, the Levant). Photo: Philipp Gunz To understand the reasons for the subdivision of human populations and how these divisions have evolved over time, researchers have examined the climates and environments of Africa that give an image of livable areas changing and often isolated. 19659020] Archaeologist Eleanor Scerri “/> Archaeologist Eleanor Scerri
Many of the most inhospitable regions of Africa today, such as the Sahara, were once wet and green, with intertwined networks of lakes, rivers and abundant wildlife. In the same way, some humid and green tropical regions were formerly arid. These changing environments have led to subdivisions within animal communities and sub-Saharan species have similar phylogenetic patterns in their distribution.
The changing nature of these livable areas means that human populations would have gone through many cycles of isolation leading to local adaptation and the development of a unique material culture and culture. organic makeup – followed by a genetic and cultural mix.
"The convergent proofs of these different domains underline the importance of considering the structure of the population in our models of human evolution", said the co-author Lounes Chikhi of the CNRS in Toulouse and l & # 39, Instituto Gulbenkian de Ciência in Lisbon. "This complex story of the subdivision of the population should therefore lead us to question the current models of changes in the size of the old population and perhaps reinterpret as changes in connectivity," he added. Africa was multiregional
"Our ancestry was multiethnic and the evolution of our material culture was, well, multicultural.We must look at all regions of Africa to understand human evolution . "
