Homo

All the skulls of the great apes were equally large. Until homo sapiens got fifth

by

Talk about the human evolution is talking about a gigantic puzzle of which we have completed a large percentage, but whose last pieces resist us. There are many who continue trying to put these pieces together, and each new fossil studied brings us one step closer to the goal… or to rethink everything. One of those questions was at what rate the hominid brain evolved compared to that of the great apes, and the conclusion of a new study It has been devastating. Double. The hypothesis. The researchers at University College London, led by the Spanish Aída Gómez-Robles, started from a well-known premise: current humans have brains about three times larger than those of our closest ape relatives. And not only a different sizealso a noticeably different cranial structure. While most great apes have forward-projecting faces and small brains, humans have a flatter face with a larger head and rounded. The exception among the apes would be the gibbons and their heads were rounded, but with much smaller brains. The hypothesis they used was that these craniofacial adaptations evolved at an accelerated rate in humans thanks to the advantages of having a large brain, but also that social factors would have influenced this accelerated transformation. The study. The team examined virtual models of skulls of several species of modern primates. Thus, they analyzed the skulls of seven species of “great apes” including humans, two species of gorillastwo of orangutans, chimpanzees and bonobosas well as nine species of hylobatids or “lesser apes”, like the aforementioned gibbons. To do this, and using a technique that allows landmarks to be mapped onto anatomical structures, the researchers divided each skull into four sections. They analyzed the markers of the upper face, lower face, front and back of the head and compared between all the skulls analyzed. As a control group, they used hylobatids, since the species separated from hominids about 20 million years ago and they realized something: while gibbons are very similar to each other, hominids are very different from each other. And, among them, humans are the ones that evolved the most. At an astonishing speed, too. Face + neuroskull. The conclusion is that the human brain It evolved twice as fast as that of other hominids. Studies have already been done on additional factors driving accelerated changes in the brain and skull, but this study is the first to quantify the speed at which different species evolved. And, in addition to speed, what they found is that the human face transformed almost as quickly as the neuroskull. Brain expansion and facial flattening are related, but in other species there is not such a clear relationship between the evolution of the neurocranium and the face. Therefore, the team concluded that there was something external at play: a selective pressure caused because we started living in a society. “The face is the interface through which we interact with other people, so a possible explanation is that the selective pressure that caused its accelerated evolution is related to how we interact with each other in a social group,” exposes Gómez-Robles. Implications. This has not happened exclusively with humans. In the case of gorillas, the UCL team concluded that they had had the second-fastest rate of cranial evolution, probably also driven by social selection, which means a larger cranial crest is a symbol of higher social status. Now, as we said at the beginning, although the UCL study has demonstrated the evolution of human brain growth in relation to that of other similar species, there are still pieces of the great puzzle to put together. Future studies can examine other aspects to better understand what were those biological or social factors that drove the accelerated cranial development in humans. Images | UCL, Jacklee In Xataka | A 4.4 million-year-old ankle has rewritten human history: our first steps were not as we thought

A one million years of years suggests that the ‘homo sapiens’ does not come from Africa

by

The history of human evolution is a fascinating puzzle that we lack many pieces. Each new fossil adds details, but occasionally, one of them does not fit the image we had. Or rather, It forces us to redraw the puzzle completely. This is what has just happened with the analysis of a skull of one million years old found in China, an investigation that, according to its authors, “totally changes” our understanding about when and how we arise, since I would question Our origin based in Africa. The study. Published In the prestigious Science magazinea team of scientists from China and the Museum of Natural History of the United Kingdom, a posture that the lineage of the Homo sapiens began to separate from their relatives, such as Neanderthalsat least half a million years before what was believed. And this is not a short time. The skull The protagonist of this story is the skull of Yunxian 2approximately one million years old, which was damaged. This caused that at first it was classified as the skull of a Homo erectus, One of our most primitive ancestors. But nothing is further from reality. Thanks to digital reconstruction technology, which included computerized and modeled tomographies, researchers were able to restore their original form. The analysis. Once the results were had, the surprises arrived. The skull did not belong to a Homo erectus, It showed a mixture of primitive and modern features. According to the study, Yunxian 2 is actually an early member of the clado Homo Longi, a sister species of Homo sapiens which also includes Mysterious denisovans. “Our research reveals that Yunxian 2 is not Homo erectusbut an early member of the clado Longi And it is linked to the Denisovanos, “said Professor Chris Stringer, co -director of the research.” This changes the thought a lot because he suggests that a million years ago, our ancestors had already been divided into different groups, which points to a much earlier and more complex human evolutionary division of what was believed, “he continued explaining. New temporal line. Until now, most genetic studies placed divergence between the lineage of the Homo sapiens and that of the Neanderthals about 600,000 years ago. However, this new analysis has changed everything and the dates remain as follows: Origin of the clado sapiens: It is now estimated at approximately 1.02 million years. Origin of the clado Longi: It is calculated in about 1.2 million years. Separation of both lineages: the study places the divergence between the lineage sapiens and the Longi 1.32 million years ago. This implies that three large groups of humans with large brains –Homo sapiens, Homo Longi (including denisovanos) and Neanderthals – could have coexist for almost a million years, much longer than was thought. Africa. Although the appearance of these fossils in the Asian continent can make us think that the origin of our ancestors is not in Africa as thought, we must have caution. Professor Stringer himself, one of the study authors, warns that there is not enough evidence to affirm that our species evolved in Asia instead of in Africa. The task that is now ahead is to select fossils with a similar age found in Africa and Europe and do the same study. That is why the scientific community is enthusiastic right now, but in a critical position. Dr. Aylwyn Scally, an evolutionary geneticist at the University of Cambridge, points out that both genetic and fossil -based analysis have significant uncertainties, especially when establishing such old chronologies. “More evidence is needed to be safe,” he says. What is clear is that Yunxian 2’s skull has opened a new and exciting window to our past, demonstrating that the history of human evolution is much deeper and more complex than we imagined. Images | Ranjit Pradhan In Xataka | “This is not a penguin.”

In 1958 we found a skull with 300,000 years in China. The problem is that we do not know what “homo” belongs

by

It all started a 1958 day when some peasants from the province of Guangdong in China were collecting guano of bat in a cave and noticed something unusual: bone remains that looked like a human skull. They warned local researchers, who cataloged the piece and baptized it with the name of the nearest people, Mabaand the number ‘1’. When did this be live? At some point in the period between 130,000 and 300,000 years ago, and the big question to answer was to what extent It was our ancestor. A recent study already has the answer. More or less. The ‘Chinese Neanderthal’. You will be wondering how such an extremely open temporal fan is handled, and the answer is that it is complex to perform a more precise dating due to complexity of both the site in which it was found and the features of Maba 1. At first, the specimen was nicknamed as’ the Chinese Neanderthal‘Due to cranial similarities with that species, but other studies have dismantled that hypothesis, bringing it closer to homo. It does not fit. But there was still a problem: facial similarities and microtomography analysis rule out that it was a neanderthal, yes, but it is not fully fits with a Homo erectus or with the Homo sapiens. Either with those Denisovanosand the problem is that it can be many things. Facial features, such as nasal prominence, brings Maba 1 to Neanderthals, but the neurocranium It has similarities with Homo Heidelbergensis and Homo Erectus. However, the cranial volume is comparable to that of modern humans and everything adds to a set that is very different from other Chinese fossils of the Pleistocene. Summary: We have no idea. Seeking to learn more about him, the authors of A new study carried out by researchers from the Institute of Paleontology and Paleantropology of Vertebrates of the Chinese Academy of Sciences analyzed the cranial cavity, the diplus vessels and the rest of the internal structures of the skull. Using the technique of tomography, researchers discovered that MABA 1 does not belong to a single class: it belongs to many. And the truth is that it is not so strange to find hominids of this period that they do not fit completely into established categories. No, it is not a “lost link”, at least not in the most colloquial sense, but it seems to be an individual belonging to those cases than They blur the limits between different species human 3D reconstruction of the skull for study But it teaches us something. This whole case reminds me of the episode of ‘The Simpsons‘In which Lisa finds the skeleton of an’ angel ‘and takes a piece to the local archaeologist to investigate it. After the evidence (which we later knew he did not make), his conclusion was that the results were not conclusive. With Maba 1 something similar happens, but it does leave us an important lesson. The researchers comment that “the internal structures of MABA 1 show a combination of morphological characteristics found in several species. And these findings further evidenced the high morphological variability among Asian hominids in the middle pleistocene.” In fact, Maba 1 is a perfect example of that complexity in the human evolution that we commented, since the mixture of features reminds other contemporary fossils found … in Africa. Researchers are clear that “currently, it cannot be definitively classified in any known hominid taxon”, but also that it remains a key fossil to understand the diversity of the hominids of the Middle Pleistocene in Asia. At the moment, it is not a Neanderthal and, now, we also know that it is a “no erectus.” We will see what happens in future investigations, but Maba 1 is not unique. Images | Ryan Somma, Mankuen In Xataka | The “ghost species” with which our ancestors were settled and disappeared without (almost) leave a trace

For thousands of years, Neanderthals and Homo Sapiens tried to mate insistently. Genetics had another idea

by

In 1856, while they worked in A limestone quarry Near Düsseldorf, two Italian workers found a basin full of bones. They thought they were the remains of a bear and approached a teacher of a nearby city, known for being a bone collector. They had no idea what they were about to provoke. The antecedent. When he saw the bones, Johann C. Fuhlrott He realized that they were not from a bear, he took the bones to the University of Bonn and, next to Hermann Schaaffhausethey communicated the finding to the world. No one took them very seriously. It was said that it was a Russian cosaco with rickets that persecuted Napoleon for Europe. Until almost a decade later, the Irish geologist William King He reached a revolutionary conclusion: we had not always been alone. But why are we now? With the discovery of Homo Neanderthalensis They opened many unknownsbut there is one that has been chasing us for almost 200 years: why did they disappear? How is it possible that such an old, so robust species, that had survived so many things disappeared without more? Why were we left alone? To all these years, scientists have given numerous hypotheses and theories. From Prehistoric genocides to A slow and agonized eclipse. However, Ludovic Slimak, researcher at the Center for Anthropobiology and Genomic of Touluse and one of the greatest international experts in Neanderthals, You have another idea. The forms of love (and what is not love). For Slimak, if we apply the knowledge of cultural anthropology to what Paleogenetics is telling us, the image is quite different. And, as in all traditional societies in which strong identities coexist, it looks like the different human communities exchanged women. From our perspective, mere expression is already a savage. But from the perspective of anthropology, those “family crossing” processes were basic to ensure stable alliances between different communities. And that, if we take into account that we are loads of DNA Neanderthal, it seems to be what happened. However, As Slimak points outthat “fusion” of lineages never came to occur. The question is why. A story (genetically) impossible. We know that Neanderthals and Sapiens crossed and They had offspring. But we also know that a significant part of it were sterile people unable to reproduce. That is, although the communities tried to lock these relationships and alliances based on miscegenation, the thing did not work. Searching. It’s curious, Slimak said in An interview for Livesciencethat “when you are looking for old DNA (40,000 to 45,000 years ago) all these sapiens early have recent DNA, and That is why we have (DNA Neanderthal) today. But when you arrive and try to extract DNA from the last Neanderthals, contemporaries of these first sapienslet’s say between 40,000 and 50,000 years ago there is not a single Neanderthal with DNA sapiens“ Curious and very possibly one of the keys that explain because the most numerically and genetically diverse population of Sapiens won the departure to the Neanderthals. That is, why we were alone. Image | SUCHOSCH In Xataka | If the question is “when the Neanderthals and the Sapiens were crossed,” we now have the answer: about 47,000 years ago In Xataka | The “ghost species” with which our ancestors were settled and disappeared without (almost) leave a trace *An earlier version of this article was published in February 2024

Log In

Forgot password?

Forgot password?

Enter your account data and we will send you a link to reset your password.

Your password reset link appears to be invalid or expired.

Log in

Privacy Policy

Add to Collection

No Collections

Here you'll find all collections you've created before.