UNDER THE MICROSCOPE:LAST WEEK I described the theory of evolution through natural selection. This theory has had more effect on the science of biology and on the way humanity views itself than any other scientific theory. The theory has sometimes been misinterpreted in a social context and this has contributed to some of the worst atrocities ever perpetrated by human-kind.
The theory of evolution through natural selection is the scientific explanation of the development of life on Earth from the simplest beginnings about 3.8 billion years ago to its present flowering. The theory, supported by a massive body of evidence, explains how all life is inter-connected. It is the central unifying theory in biology and, in the words of Theodosius Dobzhansky (1900-1975), the great evolutionary geneticist: “Nothing in biology makes sense except in the light of evolution”.
Darwin’s theory had profound implications for religion, showing that the Christian account of the origin of species as described in the Book of Genesis should not be interpreted literally. According to Genesis, God created all biological species individually about 6,000 years ago in more or less the same form as we find them today. Darwin’s theory says that existing species, including humans, are descended with modification from a long line of previous forms. Humans are descended from an ape-like creature and our hominid line diverged from the ape line several million years ago.
The Genesis account was universally accepted throughout Christendom before Darwin’s theory, so, naturally, Darwin’s proposal came as a big shock. The flavour of this shock is conveyed in the words attributed to the wife of the Bishop of Worcester when Darwin’s ideas were explained to her: “Descended from the apes! My dear, let us hope that it is not true, but if it is, let us pray that it will not become generally known”.
However, mainline Christianity fairly quickly came to terms with the theory of evolution. The Catholic Church has no objection to the theory as regards its explanation of the origin and development of species generally, including the human body, but holds that the supernatural “soul” is inserted into the body by God. Today only a minority of European Christians reject evolution, but a more significant Christian minority in the US rejects evolution and actively campaigns against it.
Darwin’s theory completed the revolution begun by Copernicus in 1453, showing that man’s home has no special place in the universe. The Earth does not sit at the centre of the solar system but rotates around an ordinary star in a galaxy containing billions of stars, in a universe containing billions of galaxies. Darwin showed that man was not specially created at the beginning and placed at the pinnacle of the living world as universally accepted in the Christian world. Man is an animal who emerged slowly from an animal with chimpanzee-like capacities, who in turn was descended from a simple marine organism.
Darwin’s proposal was enthusiastically championed by the emerging class of professional scientists, and by others. The philosopher and political theorist Herbert Spencer (1820-1903) developed an all-embracing concept of evolution to include human culture and society as well as the biological world described by Darwin. Spencer coined the term “survival of the fittest”.
Various groups interpreted Darwin’s theory to suit themselves. For example, big business claimed that Darwin’s theory showed capitalism to be the best economic model as it mirrors in social/economic terms the evolutionary struggle in the biological world with the fittest surviving and the weak going under.
The eugenics movement was started by Darwin’s cousin, the polymath Francis Galton (1822-1911). He reasoned, after reading Darwin’s book On the Origin of Species, that human society thwarts natural selection by allowing the less desirable varieties to survive. Eugenics (from the Greek meaning “good birth”) aimed to improve the quality of the human race by selective breeding, just as animal breeders selectively breed to enhance desirable characteristics. Galton didn’t prescribe that coercion be used to further his aims, assuming that a widespread knowledge of the principles of eugenics would automatically favour “sensible” breeding patterns.
Eugenics was enthusiastically taken up in the US and Europe. However, it gradually degenerated into notions of racial superiority and racial hygiene. The concept of racial hygiene was vigorously promoted in German biomedical circles. It was enthusiastically adopted by the Nazis who used it to “scientifically” rationalise their racist ideology. The whole thing ended up in the horror of the concentration camp gas chambers.
Eugenics was an awful chapter in the history of science and a permanent reminder of how careful we must be when we interpret social organisation in evolutionary terms.
UCC’s Boyle Library is holding an exhibition marking Cork’s association with Darwin. It runs until March 31
William Reville is associate professor of biochemistry and UCC’s public awareness of science officer – http://understanding science.ucc.ie
