How did biology get very complex

Darwin was not wrong!

Now that evolution critics are increasingly having their say in Germany, natural scientists are going on the offensive. There is no alternative to the theory of evolution, emphasizes the Kiel zoologist Professor Thomas Bosch in an interview with “unizeit”.


unizeit: In the USA, the representatives of »intelligent design« are currently very active. They claim that life is too complex to have come about purely by chance, through natural selection. You believe in a smart planner. What does biology think of this view?

Thomas Bosch: Nothing at all. The basic statements of the theory of evolution were first formulated by Charles Darwin and later refined by evolutionary biologists. They are: Evolution always takes place, it is irreversible, and it is also not goal-oriented, that is, there is no development for a recognizable purpose. Evolution works on all levels, from the molecule to the ecosystem. All organisms up to the most complex living beings, what possibly humans are, arise through mechanisms such as genetic diversity, selection (selection) and random effects. That is a theory, but it makes statements that can be experimentally verified.

An example: animals have a great selection advantage if they can perceive light and use it as a source of information. Presumably for this reason, the animals have developed complex light-sensing organs (eyes) in the course of the tribal history. If the selection advantage does not materialize - the animals live in eternal darkness for a long time and for many generations - these structures and organs should atrophy again. This is exactly what can be observed in a Mexican fish (Astyanax mexicanus), in which there are representatives that live near the water surface and are therefore exposed to light, as well as individuals who have long lived in caves without light. As expected by the theory of evolution, the cave fish have completely regressed their eyes. The experimentally working evolutionary biologist can, by comparing the morphology and molecular biology of the two forms, try to find out in detail which control loops and molecules the selection pressure really applies to.

Professor Thomas Bosch.
Photo: pur.pur

“Intelligent design”, on the other hand, is not a theory, nor is it science. It is the assertion: Only an intelligent cause can explain the emergence of complex living beings in particular. No experiment can test this claim. It does not make any predictions, does not propose any new hypotheses, and actually does not want them to ever be tested experimentally.

Scientists are also among the supporters of “intelligent design”. They try to take the ground with logical arguments of the theory of evolution. Does the theory of evolution leave any questions unanswered?

Yes. The theory of evolution cannot explain a lot. To this day we have no explanation for how complex structures arise out of themselves. This is one of the very big puzzles that cannot be described with the basic laws of physics and biology. The scientist is always puzzled, and every day we face unsolved problems. But all puzzles have to be solved with scientific theories, with observations, with experiments and with measurements. And you have to be able to reject a theory from time to time. The theory of evolution expressly allows this if new experimental findings require it.

But currently there are no other theories about the origins of life that stand up to scientific scrutiny?

Absolutely not. The theory of evolution has now become enormously complex. It is supported by many observations outside of biology - for example from physics, chemistry or geology. To date, there is no theory that shows that the theory of evolution is wrong or not true. It is a very lively theory that is at the center of today's natural science, which is approached by very different subject areas and leads to a real increase in knowledge. It's not just a belief.

According to recent polls, one in two Americans believes that we are not the result of biological development. Why do you think the opponents of evolution are so successful?

I mean this is a human problem. Obviously, it is not so easy for people to accept that they are a tiny cog in the great gears of life. People always see themselves as something special. »Intelligent Design« corresponds to this wish with the representation of the human being as »at the height of the development«. We know these arguments from the past, when there was an argument about whether the earth was the center of space or not. I thought we had overcome this time since the Middle Ages.

However, the representatives of "Intelligent Design" are also very clever. So they don't deny that there is some development. After all, there are fossils that are millions of years old. They also accept that there is a certain higher development. You call this microevolution. They exclude human development from it. That is the macroevolution. From a scientific point of view, this is bottomless nonsense.

How should this development be dealt with?

We must not underestimate this and we have to take an offensive approach to this development. There are now families who do not send their children to school because they do not want to be exposed to the theory of evolution. I have an e-mail from a teacher from Stuttgart which says: "To our astonishment, opinions are increasing at our school that the theory of evolution is subordinate to a creationist theory of creation."

It can't get as far as the United States, where some states are banning evolution textbooks from teaching.

We are an enlightened, rational and scientifically oriented society. It has nothing to do with belief and religion. This has nothing to do with the question of whether there is a God or not. The question here is how life comes about, how do organisms develop, and which processes make this possible. The theory of evolution gives a satisfactory answer to these questions. (ne)
Keyword: Intelligent Design (ID)
Man is too complex to have come about by chance. A superordinate force, some kind of intelligent builder, must stand behind it. These are the main messages of the "Intelligent Design" (ID) movement. For some years now, the supporters of the ID have been mobilizing against the theory of evolution and its communication in American schools, museums and public institutions. You are close to the conservative "Discovery Institute" in Seattle, Washington / USA. The institute is funded by Christian conservatives.

In contrast to the creationists, who take the creation story of the Bible literally, the proponents of "intelligent design" do not completely deny evolutionary developments in nature. They accept, accept that the earth is billions of years old and that life came into being gradually. But behind this they see an intelligent cause. According to a ruling by the US Supreme Court, creationism cannot be taught in the classroom.

The »intelligent design« is generally counted among the pseudosciences. The ideas are, however, firmly anchored in American society. According to surveys over the past few years, around half of the American population professes creationism. In contrast, German society is increasingly behind Darwin: In a Forsa survey at the end of 2005, 61 percent of Germans said that the theory of evolution was the correct explanation for the development of all living things.


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