Did man descend from ape, do Neanderthals and modern humans descend from the same species, and how micro- and macroevolutions differ. Evolutionary scientists are trying to make a compelling case for this theory, which skeptics disagree with.
Many people firmly believe in the theory of evolution and in the fact that all living organisms will have a common ancestor if you trace their development far enough into the past. But there are also many people who, in turn, believe that the theory of evolution is pure deception, and the statement that humans can have a common ancestor with apes is nonsense.
One of such skeptics is our reader Adem Ökmen. Adem recognizes that plants and animals can adapt to different environmental conditions (microevolution), but does not believe that such adaptation can lead to the emergence of new species (macroevolution), as the theory of evolution claims.
Therefore he wrote to us: “I read a little about what evidence there is that macroevolution exists at all. I myself do not recognize macroevolution, because I believe that there is no concrete evidence of this,”writes Adem and says, for example, that there are gaps in the fossil finds, so there are not enough transitional forms between different species.
Other skeptics among Videnskab readers
Adem is not the only one of our readers who prefers alternative explanations for the existence of all life to the theory of evolution. For example, another reader suggested last year that there is no evidence that we have a common ancestor with "other apes."
You can read the answer of science to this question in the article "Are we quite sure now that man comes from apes?" (Er vi nu helt sikre på, at mennesket nedstammer fra aberne?)
Promotional video:
To convince Adem and all the other skeptics, we turned to two scientists who were happy to support the theory of evolution and try to convince doubters that it was they, and not this theory, that were wrong. These two scientists are Professor Tobias Wang from the Department of Biological Sciences at the University of Aarhus and Professor Mikkel Heide Schierup from the Center for Bioinformatics at the same University of Aarhus. Tobias Wang studies, among other things, how animals adapt to their environment, and Mikkel Heide Schirup studies how monkeys became humans.
We have a lot of evidence
Tobias Wang begins with Adem's argument that there are gaps in the fossil finds. “But until we find fossils for each specific species that once existed, gaps will remain. Is this a good argument for the fallacy of the theory of evolution? I do not think so. In addition, today we have so few fossil gaps and so much evidence of relationships between many species that it is actually very difficult to imagine that there was no evolution,”says Tobias Wang.
Genetics and fossils suggest evolution
It is not only the giant library of fossils of almost every imaginable extinct species, taken together, unequivocally supports the theory of evolution.
Tobias Wang, continuing his defense of the theory of evolution, emphasizes another fact - that there is a clear connection between the kinship of organisms and genetics. “The closer the family ties of animals, the more they have in common in their genetics. This is very compelling evidence of common ancestry, and it fits well with the idea that two closely related species at some point in time separated from one common species and went their own way,”says Tobias Wang.
“Moreover, not a single species, extinct or living, has been found that we cannot genetically or morphologically link to other species on the tree of life,” he says.
Tobias Wang clarifies that a single species that could not be explained by the theory of evolution would have been enough for this theory to fall apart. “But there was no such thing. All current and past species can be explained by evolution,”says the professor.
No difference between micro and macro
Arguing against the theory of evolution, Adem said that he believes in microevolution, that is, in the fact that species can adapt to a changing environment. And he questions macroevolution. According to Tobias Wang, there is no point in dividing evolution into micro and macro. “Evolution usually happens in very small steps. But if you take many small steps, over time, they turn into big changes. It's that simple,”says Tobias Wang.
As a good example of how microevolution, if you wait long enough, automatically leads to macroevolution, Tobias Wang brings dogs. For example, both the Great Dane and the Chihuahua now belong to the same species. The origins of both can be traced back in time to 10 thousand years ago to wolves.
Micro / macro evolution is happening all the time
But if you send all Great Danes to Australia, and all Chihuahuas to North America, then in 100 thousand years, according to Tobias Wang, they will no longer belong to the same species. Since they will no longer be able to mate with each other, they will not be able to exchange genetic material. In addition, they will each adapt to their environment, which means they will develop in different directions.
Thus, they form two new species, which will go back to one general species - the ordinary dog. “They are already and right now are gradually transforming into new species. If an archaeologist 10 thousand years later found the skeletons of the Great Dane and the Chihuahua, he would not believe that they are the same species,”says Tobias Wang.
This same kind of micro and macro evolution, according to Tobias Wang, is happening all over the world all the time. This happens naturally as well, not just because some people like horse-sized dogs and others prefer to fit in a bag. This can happen so simply that when, for example, a lake for some reason splits into two, and one species of fish ends up in two new lakes, then over time, two different species of fish appear.
People develop too
However, we don't have to look to dogs or fish to see that evolution exists. It is enough to look at ourselves: and here our second professor from Aarhus University comes on the scene. According to Mikkel Heide Shirup, there is no doubt that we have a common ancestor with monkeys. Our genes are crystal clear about this, he explains. In humans, 99% of genes coincide with chimpanzees, 98% with gorillas and 97% with orangutans. We're pretty much the same.
Mikkel Heide Schirup explains that you can figure out how long ago the genes of two species began to differ from each other, and thus calculate when we were the same species. This can be calculated by finding out how quickly mutations occur in genomes, and Mikkel Hedi Schierup and his colleagues did just that on the material of 50 Danish families.
During the study, scientists looked at what kind of genetic variation the child has that neither parent has. These will be the new mutations that appear in the child. The number of new mutations is almost constant from year to year. Scientists call this a molecular clock. “This way we were able to see how quickly the genome changes in one generation and extrapolate the result thousands of generations back in time,” explains Mikkel Heide Schirup.
Genetic findings match fossil findings
By calculating how many mutations - and therefore generations - were needed to create genomic differences between us and other apes, the researchers were able to figure out when we were the same species.
You can read more about these findings in the articles: “The gorilla genome gave us new knowledge about human development” (“Gorillaens genom giver ny viden om menneskets udvikling”), “The orangutan has powerful genes” (“Orangutangen har stærke gener”) and “Extensive new knowledge about the monkey genome provides unique knowledge about evolution”(Nyt omfattende viden om abe-genomer giver unikt indblik i evolutionen).
The result of genetic research was that orangutans and humans each went their own evolutionary path 12 million years ago. Then we split from gorillas 10 million years ago and finally 6.5 million years ago from chimpanzees.
These results, based solely on studies of genetic differences, also harmonize with the dating of fossil remains of species that scientists believe are generic to us and to other great apes.
“Thus, we see that genetics and fossils are consistent and further support the theory of evolution,” says Mikkel Heide Schirup.
The theory of evolution is as reliable as the law of gravitation
According to Mikkel Heide Schirup, doubting the theory of evolution makes no more sense than doubting the law of gravitation. Both were tested in scientific experiments that could refute them, but this did not happen.
According to the professor, a huge number of experiments were carried out that confirmed the theory of evolution. For example, he mentions that the theory of evolution explains why some people have light skin while others are dark. This is due to evolutionary adaptation to sunlight, which markedly changed the appearance of humans.
Evolutionary theory also explains why people in northern Europe have evolutionarily adapted to the consumption of cow's milk and why bacteria develop resistance.
“Whatever experiments we do, we can explain their results using the theory of evolution. All our experiments and all studies are in line with theory. When so many facts clearly indicate that the theory is correct, and a person still does not believe in evolution, it means that he simply does not want to take into account all this numerous evidence,”- Mikkel Heide Schirup.
We hope Adem will find these answers useful. In any case, we thank him for the question and give him a T-shirt with the image of a distant relative of a person (monkey). We also thank Tobias Wang and Mikkel Schirup for the good answers.
Neanderthals and modern humans descend from the same species
When two populations live long enough in isolation from each other, they each develop into a different species. For example, this happened with Neanderthals and modern humans. Both species descend from the same common ancestor, but the Neanderthals left Africa about 500 thousand years earlier than modern humans.
This means that when we met again 450 thousand years later, we were already in the process of forming two different species, and our genes were not completely compatible. Therefore, we could not completely share our genetic masses with each other when we had sex with each other.
Thus, as a result of mating of modern humans and Neanderthals, only part of the Neanderthal genome entered the genetic mass of modern humans. This means that when scientists look at the genomes of modern humans, they see that most of its genetic mass differs from the genetic mass of Neanderthals by 500 thousand years, and only a small part of it differs by 50 thousand years. Therefore, scientists have concluded that modern humans and Neanderthals mated about 50 thousand years ago.
Kristian Sjøgren