We are searching data for your request:
Upon completion, a link will appear to access the found materials.
A study led by Spanish researchers has revealed that theHomo erectus, the first human ancestor to spread across the Viejo world, from Africa to Southeast Asia, and until now considered slender and slender, it was actually compact, squat and robust.
This is revealed by a work ofpaleoanthropologists of the Higher Council for Scientific Research (CSIC) and the National Center for Research on Human Evolution (CENIEH), which have reconstructed the shape of therib cage of the specimen of Homo erectus known as theTurkana child, a 1.5 million year old juvenile skeleton found in Kenya in 1984.
The study, co-led byMarkus Bastir, of the National Museum of Natural Sciences MNCN-CSIC, andDaniel Garcia Martinez, from CENIEH, is published in the magazineNature Ecology and Evolution. Surprisingly, the Turkana boy had a chest deeper, wider and shorter than that of modern humans ”, says researcher Markus Bastir.
"This suggests that theH. erectus it had a more robust body construction than was supposed, since until now the body shape of this species was seen as slender or stylized, which was associated with its ability to travel long distances ”, he adds.
“Therefore, it appears that the slender shape of the modern human body, with a narrow thorax and pelvis, evolved more recently than previously thought. Instead of appearing as early as the appearance ofH. erectus, about two million years ago, would have appeared with our species,Homo sapiens”, Explains García Martínez.
A large lung capacity
Studies on how this individualH. erectus walked and ran have been largely limited tolegs and thepelvis. However, for the endurance race, theirrespiratory capacities would also have been relevant.
“Until now, this aspect had not been investigated in detail, since assessing chest movement and respiratory capacity based on fossils fragmented ribs and vertebrae is difficult with conventional methods ”, explains Bastir. “Now, thanks to the introduction of virtual imageand of increasingly sophisticated reconstruction, this study has finally been possible ”, he adds.
“In this research, it has been possible to reconstruct the virtual rib cage in3D of the young man from Turkana, and it has been possible to predict his adult thoracic shape ”, explains García Martínez. "Furthermore, the shape of his rib cage was compared to that of modern humans and that of an individualneanderthal, to investigate the movement of their breathing through virtual animation ”, indicates the CENIEH researcher.
This study also addresses the fact that the shape of our modern body can be linked to arespiratory kinematics optimized for long distance running as well as other endurance activities.
"TheH. erectusmaybe it wasn't himrunner slim andathletic long distance that we imagine ”, says Bastir. “In fact, this is consistent with some body weight estimates from theH. erectus, which propose that this species was heavier than previously believed. This iconic ancestor probably looked a little less like us than we portrayed him over the years. "
Homo erectus: a body shape adapted to the environment
The evolution of the human body shape reflects the way in which human ancestors adapted to the environment in which they lived. Modern humans,H. sapiens, have a relatively tall and slender body that contrasts with the body shape of the Neanderthals, shorter and stockier.
Scientists have traditionally assumed that the modern body shape originated with the earliest representatives ofH. erectus in the context of someclimate changes related to the recession of thetropical forest African, about two million years ago.
Modern tall and slender bodies could be evolutionarily advantageous in the dry savanna climate whereEast africa it was beginning to turn. This is because this slim body would have helped to avoid body overheating, as well as being useful for running long distances on open ground.
According to this conception, the fossils attributed toH. erectus until now pointed out that this species already hadlegs longer and somearms shorter than their ancestorsAustralopithecus, which had abipedal gait quite efficient, but they also possessed the ability to climbthe trees.
Some characteristics of modernity that is currently observed in the human species could be seen in theH. erectus 1.5 million year old juvenile from Turkana (Kenya), which is the fossil ofH. erectus most complete found to date. Now, this new study qualifies this conception, by showing thatHomo erectus they had a more compact and robust body than had been thought.
Bastir et al. "Rib cage anatomy in Homo erectus suggests a recent evolutionary origin of modern human body shape".Nature Ecology and Evolution. DOI: 10.1038 / s41559-020-1240-4