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The Mysterious Origins of the Human Brain



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Early brain filling transvestite From Dmanisi, Georgia, shown in turquoise. Their structure provides new insights into the evolution of the human brain 1

.8 million years ago.

Image: M.PONCE DE LEÓN AND CH.ZOLLIKOFER / UNIVERSITY OF ZURICH

Tracing the emergence of human-like brain traits in the hominin fossil record can provide evidence of the timing and processes of brain changes and provide insights into the behavior of our ancestors and relatives. Since brain tissue rarely fossils, changes in the size, shape and organization of the brain are collected from the brain’s endocasts. (Model of the inner surface of the brain) (1After his observations of the cerebral imprint preserved in a fossil skull specimen from Olduvai (Tanzania) (2Phillip V. Tobias, paleontologist, said: “The evolution of the hominid has reached a new level of organization… with its emergence. transvestiteSince then, there has been some debate over whether the human-like brain organization coincides with the appearance of the genus. transvestiteOn page 165 of this issue, Ponce de León. And faculty (3) Challenge this view by proposing that transvestite In Dmanisi (foothills of the Georgian Caucasus) 1.85 to 1.77 million years (Ma) ago, it has been shown to be a traditional brain organization.

Reconstructing the chronology and evolutionary patterns of the hominin brain requires good knowledge of the subtle changes in the brain region. In this sense, the inferior part of the forehead lobe, which houses Broca’s hat, is the focus of a thorough investigation and intense discussion (4In addition to being an important landmark for brain reorganization, Broca’s hat plays a fundamental role in language production and the understanding of evolution, an equally interesting topic. Broca’s surviving human cap is structurally different from our closest living relatives, chimpanzees and bonobos. Chimpanzees and bonobos have one different groove in that area, called the frontobitan sulcus. This does not exist in humans, where there are two vertical grooves instead. In the study of human evolution, it was assumed that the brains of chimpanzees and bonobos were closer to the original state of the hominin brain. Within this context, “one groove condition” is interpreted as an ancestor.

This is despite the recent discovery of important infectious agents and recent computer-assisted revisions of the fossil record (5, 6Little is known about the brain in the early days. transvestiteThis unfortunate situation can be explained in part by the lack of the complete or at least part of the fossil skull from that period. For example, the oldest human remains from Ledi-Geraru (Ethiopia) were up to 2.8 Ma.7). Early transvestite An example with a useful amount of endocast data. The (description of the organization of brain regions) comes from areas in Africa and Asia with relatively less geological conditions (less than 1.8 Ma) (8, 9) Leave a gap of about 1 Ma in the knowledge of the evolution of the human brain. In terms of front-end organization, destroying 1 Ma in the active fossil record is important. Early hominins wandered in Africa before 2.8 Ma represented the region’s relatively traditional organization (4), While the imprint on the human endocast later indicates the acquired human condition (5) .In this case, the assumptions of the obtained organization, which were formed at the same time as the earliest human beings, cannot be discounted.

Evolutionary scenario for hominin frontal lobes

The evolutionary situation is based on evidence of brain changes preserved in the fossil record and examined by Ponce de León. And faculty Dark gray curves indicate the location of the frontal bone.

Graphics: N.DESAI /science

Through a thorough study of the remarkable assembly of parts from Dmanisi and the refinement of African and Asian fossil materials, Ponce de León. And faculty Build new understanding of brain organization early. transvestite Generally and Standing man (Meaningful summer) In particular, challenging the notion of the completely derived human brain at the time of the earliest representative of the genus. transvestiteDmanisi’s hominin fossil sites are distinguished for their geographic context (Europe) and in chronological order (1.85 to 1.77 Ma) (10) .For this reason, the collection of fossils in this area is one of the oldest diffusion documents of transvestite Out of africa By combining various methods of capturing high-resolution images (Including synchrotron irradiation) and three-dimensional modeling techniques. (Including geometric morphine), the author showed that the endocasts of H At about 1.8 Ma, reflecting the primitive organization of the forehead, while the later H Examples in Southeast Asia and Africa show acquired conditions (see figure), so the authors suggest that the human-like frontal lobe organization arose after the genus. transvestite And spread the fastest in Africa

The questions that have to be addressed further relate to the underlying nature of the evolutionary process. What sort of selection pressures might be responsible for reorganizing the front end? This question has significant functional and behavioral implications, because in addition to language, Broca’s hat has also been implicated in tool making (11The other possibility that deserves more attention is that none of these selections, and the changes that affect the Broca limit, are a byproduct of the reorganization of other areas of the brain, and eventually. The emergence of language As a result of washing off (Previous anatomical properties have been re-selected) (12In that sense, the description of the brain imprint of the previous endocasts. transvestite For example, a braincase recently found at Drimolen (South Africa) (13), And discovering future new examples from that period will be critical to understanding the evolutionary context of these brain changes.


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