Research identifies regular climbing behavior in a human ancestor

A new examine led by the College of Kent has identified proof that human ancestors as recent as two million several years in the past could have regularly climbed trees.

Going for walks on two legs has long been a defining attribute to differentiate contemporary people, as properly as extinct species on our lineage (aka hominins), from our closest dwelling ape family: chimpanzees, gorillas and orangutans. This new study, primarily based on assessment of fossil leg bones, presents proof that a hominin species (considered to be both Paranthropus robustus or early Homo) regularly adopted hugely flexed hip joints a posture that in other non-human apes is associated with climbing trees.

These conclusions came from analysing and evaluating the interior bone buildings of two fossil leg bones from South Africa, identified about 60 several years in the past and considered to have lived among one and three million several years in the past. For each fossils, the external form of the bones were incredibly related displaying a a lot more human-like than ape-like hip joint, suggesting they were each strolling on two legs. The scientists examined the interior bone structure since it remodels through lifetime primarily based on how folks use their limbs. Unexpectedly, when the team analysed the within of the spherical head of the femur, it showed that they were loading their hip joints in distinct techniques.

The study task was led by Dr Leoni Georgiou, Dr Matthew Skinner and Professor Tracy Kivell at the College of Kent’s Faculty of Anthropology and Conservation, and integrated a large global team of biomechanical engineers and palaeontologists. These benefits exhibit that novel data about human evolution can be hidden in just fossil bones that can change our comprehending of when, where by and how we became the people we are today.

Dr Georgiou mentioned: ‘It is incredibly enjoyable to be equipped to reconstruct the real behaviour of these folks who lived hundreds of thousands of several years in the past and each individual time we CT scan a new fossil it is a possibility to discover some thing new about our evolutionary historical past.’

Dr Skinner mentioned: ‘It has been complicated to resolve debates with regards to the diploma to which climbing remained an important behaviour in our earlier. Evidence has been sparse, controversial and not commonly approved, and as we have shown in this examine the external form of bones can be misleading. Even more assessment of the interior structure of other bones of the skeleton could reveal enjoyable conclusions about the evolution of other important human behaviours this sort of as stone instrument creating and instrument use. Our study team is now growing our do the job to seem at arms, feet, knees, shoulders and the backbone.’

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The study paper ‘Evidence for recurring climbing in a Pleistocene hominin in South Africa’ is posted in PNAS. DOI: ten.1073/pnas.1914481117

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