Where did we come from and where will we go? This question has troubled many researchers, both philosophically and biologically. But the question we are going to discuss this time focuses mainly on biology, i.e., where do we come from?
Quite a bit of fossil evidence suggests that we evolved from the orangutans or apes of the primate family. But this claim lacks key evidence and is difficult to be supported by everyone. But scientists based on the study of early fossils, this key evidence may be explained. The missing link in the human evolutionary chain may have been found, and it is possible that the question of human origins may be concluded.
Similar questions have been the subject of much scholarship since the Renaissance, and into the 19th century, Darwin's Theory of Evolution seemed to explain the problem. According to Darwin's explanation, biological evolution and natural selection are the main processes in the evolution of human beings to date.
He believes that all organisms on Earth come from a common ancestor or ancestral gene pool, and that the common ancestor of humans comes from the evolution of the southern archaeopteryx. But the extinction events that species undergo during evolution make the whole process unclear.
Simply put, we are missing key evidence of our own species evolution in the evolutionary process. The similarity of species makes it difficult to distinguish this origin experience, and modern research suggests that gene transmission between some distantly related species is more complex based on horizontal transfer of genes.
So how powerful is this fossil to be able to show people this missing link from the long river of time. The next part of this article will talk about the "missing" transitional fossil of human evolution and how it can help us to trace the origin of evolution.
The absence of natural evolution
Scientists believe that humans share a common ancestor in the evolutionary process, as do primates like chimpanzees. But in later evolution humans evolved a separate species, the genus Homo. It was from this period that humans began to break away from the evolutionary tree with chimpanzees, the primates.
Fossil evidence suggests that humans began to diverge from chimpanzees about 7 million years ago, but no more obvious fossil specimens have been found among the fossils of chimpanzees that split off. This suggests a lack of evidence for such transitional fossils in human evolution.
A transitional fossil is a biological fossil that preserves both its ancestors and the life forms of organisms that evolved after it. This is especially true when the evolved organism is completely different from its ancestor.
Darwin argued that the fossil record itself is fraught with many uncertainties and there is much data that people do not know, so if we are going to talk about evolution in this context, why not explain it by the lack of data in the geological record?
It turned out that not long after the book Origin of Species came out, the discovery of the fossils of the Archaeopteryx proved to be an important fossil in the transition from dinosaurs to birds. A growing number of transitional fossil discoveries in the post-academic period are sufficient to demonstrate that the phyla of vertebrates are related to each other to varying degrees.
Since evolution is not a single line but carries many branches, the same species may have multiple variations and subspecies that branch out. The biggest drawback of fossils, however, is that not all transitional organisms are represented in transitional fossils, and only in a very small percentage one can find them.
Why do scientists believe that the southern archaeopteryx would be an important piece of evolutionary evidence in human evolution?
It is clear that the same comes from transitional fossils. Among the fossil evidence of southern archaeopteryx, scientists found that the fossil had a distinct narrowing zone in the orbits, a lower maximum width of the skull, 35% of the brain volume of modern humans, a thicker jawbone, large molars, and relatively small incisors and canines.
All of this evidence suggests that the fossil is moving in the direction of human evolution, and most importantly, the body structure of the Southern Archaeopteryx fossil suggests that they had the ability to walk in two groups. This suggests that they had evolved some time before this.
Anatomically, the fossil pelvis resembles a human rather than an ape, and the angle of the position of the femur to the femoral joint up to the knee makes them bring the foot closer to the middle of the body. This is a physiological feature that only modern people have.
But then the question arises, since they have been evolving for some time, who were they before that? Or where did they evolve from? This question has been troubling scientists for many years, and evolution has been stuck here due to the lack of key evidence.
Puzzles from the past
Finally, in January 2013, the fossil of an unknown species was discovered in a silt 10 meters above the Gurumahar Tuff site. After carefully studying it, scientists found that it could be key evidence of human evolution.
The fossil is presumed to date from 28,000 to 27,500 years ago, and the fossil specimen, labeled LD 350-1, has been studied to show that it is the left jaw of an adult creature with skeletal parts including canine teeth, two premolars, and molars in the rest of the body. Overall, the specimen falls within the range of specimens of the Alpha species of southern archaeopteryx.
As mentioned earlier, scientists have long believed that human evolution came from the southern archaeopteryx, but due to the lack of transitional fossils, it can only be traced back in the evolutionary period. However, the anatomy of this fossil specimen is very different from that of the southern archaeopteryx, and it is closer to that of humans.
The position of the chin hole is not in a depression, it has a joint keel at a bone line protruding from the midline of the jaw, and the jaws maintain a more or less constant depth, which is very close to that of humans. In the case of southern archaeopteryx, this position would be at the deepest point below the premolars and there would be some differences in the crown of the teeth.
This suggests that the fossil appears to differ from southern archaeopteryx early on, and like other ancient humans, this jaw appears to have no distinct jaw. This strong difference shown in the teeth, scientists believe that this split out is likely caused by dietary changes.
Similar dental variations were similarly found in the KNM-ER 5431 sample later found in 2015 in the Kenyan region, where the left and right premolar teeth were significantly different from those of archaeopteryx. And it was able to be traced back to an earlier time, roughly 30 to 27 thousand years ago.
Scientists speculate that this may be the same species as the LD 350-1 sample, which would explain this transitional change in southern archaea. However, there is still a temporal difference between these, with a time difference of about 2000 years.
The latest discoveries in 2019, however, seem to explain this deficiency, with stone tools found in northeastern Ethiopia dating back 26,000 years and possibly made by the same species as LD 350-1.
These sharp stone tools allowed them to have basic productivity, and the sharper ones also proved that they had access to better resources than the southern archaea, which was very advantageous in the changing climatic species of the time.
Scientists speculate that the living area of LD 350-1 would have been drier and more open than the habitat of other species found in fossils. Based on the diversity of grazing species, the area may have resembled a modern African grassland.
Does this tell the whole story? Has the ultimate answer to the evolutionary process of mankind been found?
A definitive conclusion? Debatable
This problem is actually still difficult to understand, first of all, let's look at the great migration of the ancient apes. Starting from Africa, there were two migrations distributed respectively. The first one was roughly 130,000~100,000 years ago, and the second one was roughly 70,000~50,000 years ago.
In contrast, the distribution of hominid species in continental Europe was mainly 65,000 years ago, the main time period for the development of Homo sapiens. However, as we said earlier, the evolutionary branching of humans is very complex and a clear evidence is necessary to find the ultimate origin.
Fossils alone are not enough, and stone tools found in areas such as Ethiopia do go some way to answering some of the questions of LD 350-1. However, it is not clear to scientists whether this stone tool manufacture and culture developed independently of them or was passed down from an earlier Southern Archaic tradition.
Today scientists are still unable to find all the evidence for human origins, but as a whole, the whole process of historical change and evolution is becoming clearer. From primates to southern archaeopteryx to hominids to modern Homo sapiens, human evolution is a long process, and it is impossible to fill out the whole puzzle with just one or two pieces of fossils.
It is of great significance to us that mankind has never ceased to trace its origins. Through such research, human beings can gain a more complete understanding of themselves in terms of their biological properties and find out who they really are.