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 Editorials | At Issue | June 2005 
It's Too Late to Deplore the Evolution of the Species
 Michel Veuille - Le Monde
Dutch Education Minister Maria van der Hoeven's declarations against the teaching of Darwinism (Le Monde of 28 May 2005) recall that the theory of evolution is still rejected by those who see it as contradictory to their religious convictions. Biology, for its part, while unanimously accepting Darwinian Theory, had, for a long time, concerned itself more with the functioning of structures than the history of life.
Evolution brought little to physiology, biochemistry, or cellular biology. A spectator to the sciences could reject Darwin without disowning all the research. That is no longer the case today. The anachronism of the Dutch Minister's statement lies not so much in the obscurantist clichés she seems to unearth as in her ignorance of contemporary biology.
When Darwin pronounced his Theory in 1858, its originality lay in the idea that variations between individuals of the same species were hereditary and that these variations were selected through natural processes. But the laws of heredity were still unknown. It took a century and a half to observe genetic transmission (1900), to discover the DNA molecule (1953), and, around the year 2000, to sequence the DNA (the "genome") of several species.
The paradox is that now we know how to read a complete genome, but we still don't know how to understand it. Nonetheless, it is certain that it cannot be interpreted without taking into account the evolutionary mechanism that produced it. Each genome is like a very long text that contains the instructions for the development of each species. These species are linked to one another by the genealogy of evolution and their genomes have diverged by accumulating mutations.
Over the course of time, natural selection has preserved or modified, according to the specific case, genomes' most important or innovative parts. By comparing genomes, numerous analytical methods seek to elucidate the functions of their different parts. Thus, evolution has gone beyond the status of a simple theory to become a tool of applied research. Consequently, according to the American medical research agency (the NIH: National Institutes of Health), "the study of comparisons between species is important to identify the functional elements of the genome" (24 April 2003 edition of Nature).
Therefore, the NIH has decided to sequence the genome of several species of vertebrates and insects to tackle "the great challenge of understanding the evolutionary variation between species and the mechanisms that support it." The NIH stipulates: "The genome is a dynamic structure, continually subject to modification through the forces of evolution. The genome variation observed among people is only a tiny glance through the wider window of evolution where hundreds of millions of years of trials and errors have created the contemporary biosphere of animal, vegetable, and microbial species. A complete elucidation of the function of genomes demands a parallel understanding of the differences in sequences between species."
Thus, to understand how a gene of medical interest to humans functions, a forced detour towards that gene in beings as distant as the vinegar fly or the nematode worm is sometimes necessary...
Our own evolution is not so far distant. The common ancestor between man and the chimpanzee is only several hundred thousand generations old. We suspect that certain genetic diseases could be the consequence of evolutionary changes undergone by human beings. It has proven that natural selection among our ancestors explains, for example, hereditary physiological variations in hemoglobin and lactase. Study of the genome could reveal other similar cases.
Whether one likes it or not, evolution is our contemporary. A number of diseases described as "emergent" which have appeared in recent years result from new bacteria adapting to the human being. In 2003, the Institut national de la santé et de la recherche médicale [National Health and Medical Research Institute] (Inserm) awarded its gold medal to Miroslav Radman for his team's work on the evolution of nosocomial diseases, diseases due to particularly aggressive bacteria that have become resistant to antibiotics through the evolution of "hyper-mutative" strains.
Those who deplore the theory of evolution are like that Victorian aristocrat who, learning that man comes from a monkey, is supposed to have declared: "May it not be so! And should it be so, let us at least not know about it!"
Ignorance of evolution, however, is not without consequences. For a long time, this theory seemed mostly to satisfy logical minds, without having an impact on daily life. It was the intellectual ornament of philosophy courses, demonstrating the unity of living beings. Now, it is integral to the scientific approach. It is no longer time to ask oneself whether one must "believe" in the evolution of species. The best preparation for a scientific background that a Minister of Education can offer young Europeans is to reveal to them all that Darwin's theory has contributed to our total knowledge.
Michel Veuille is the Director of the Systems and Evolution Department at the Paris Museum of Natural History. |
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