Darwin the Genius of Evolution

Warren Hochfeld

When Charles Darwin published his groundbreaking theory of natural selection in 1859, it was received by the public with considerable discontent. His theories were introduced in his landmark publication, The Origin of Species in which he hypothesised that positive heritable traits would make it more likely for an organism to survive long enough to reproduce over successive generations: over time population adaptations that specialize organisms for a particular habitat or situation may eventually result in the emergence of a stronger organism, this process was termed natural selection. This year marks the 200th birthday of Charles Darwin and the 150th anniversary of The Theory of Evolution. Widely accepted by scientists as the blueprint for the engine of life, his work remains one of the strongest influences on modern society sculpting our understanding of what it means to be human. It was quite simply the best idea anyone ever had…

Modern scientific breakthroughs mostly confirm Darwin’s theories, providing an explanation for the physical basis of variation underlying evolution: Mendel’s genetics and the discovery of the structure of DNA provide the apparent explanation of the origin and inheritance of human characteristics. The fundamental element of this explanation is a functional unit called the gene, each of which govern, or assist in governing, the incredibly diverse array of traits within a species. Genes are composed of strands of a molecule called DNA and are located within chromosomes. The genetic message is encoded by the building blocks of DNA, which are called nucleotides. Each person's genetic makeup is a result of his/her unique sequence of nucleotides. The expression of these genes result in the production of proteins, which serve as building blocks for tissues as well as the regulators of chemical reactions taking place inside all living cells. They control everything from the colour of our eyes, the texture of our hair, the amount of oxygen one carries in their blood and many other factors.

However as our general understanding of genetic mechanisms advances, so does our ability to manipulate them. Western society has been saturated with therapeutic treatments, and with the encouragement of the medical establishment itself has started to look beyond therapeutic interventions. Conceptually, if you consider the world only at the molecular level, genetic manipulation is a logical, straightforward solution to genetic disease: if a gene seems to be causing a disease, then to cure the disease scientists must remove the “defective” gene, and substitute it with the “effective” gene. In an ideal scenario, the cell with the corrected DNA will multiply, producing more copies of the corrected gene thus freeing the body of the genetic abnormality and curing the disease. As ordinary medicine can only moderate symptoms of genetic diseases and treatments are typically only temporary, genetic manipulation has the potential to eliminate the root causes of certain diseases by repairing or modifying the patient’s genetic code.

Advocates for genetic medicine are convinced that controlling our evolutionary destiny is humankind's next great social frontier. There argument stems from personal health, individual choice, and a collective responsibility for future generations. The cornerstone concept is that everyone has the right to be "well-born” and genetic manipulation will lead to a perceived improvement of the human gene and the betterment of society as a whole. The foremost practitioner is Nobel laureate James Watson, the co-discoverer of DNA, who is an outspoken proponent of using genetic engineering to "redesign" future children and "improve" the human species. During the recent "DNA at 50" celebrations, Watson stated that, “The right to a custom-made child is merely the natural extension of our current discourse of reproductive rights.”

While natural selection favours "Survival of the fittest" evolutionary biologists have questioned whether this will actually lead to the best possible organisms in the long run. Parents in the biotech century will be increasingly forced to decide whether to take their chances with the traditional genetic lottery and use their own unaltered egg and sperm, or undergo corrective gene changes to their sperm, egg, embryo, or foetus. Of course one could choose to go with the conventional approach and let genetic fate determine their child's biological destiny, but is it not a parent’s responsibility to provide as safe and secure an environment as is humanly possible for their unborn child? Knowing their children may inherit some "undesirable" traits, is it not a parent's failure to correct genetic defects in utero, something they could have avoided had they made use of corrective genetic intervention at the sex cell or embryo stage.

2009 has been named The Year of Darwin, as universities, academic centres, and other scientific organizations all over the globe have a surplus of events planned to honour his contributions. But we can’t help but wonder what Darwin would think if he could survey the state of his intellectual achievement today, 200 years after his birth.

Darwin did not write about genetic engineering or even about genes as he lived before their time. Nevertheless, genetic engineering is a form of human selection that began before anyone even spoke of genes. Darwin did state this when comparing human selection with natural selection: “Man selects for his own good: Nature only for that of the being which she tends.” Darwin’s perspective was that human selection was not only anthropocentric, it was foolish. Darwin was a naturalist and believed that the wiser path for humanity was to leave selection to nature, because species and varieties of species selected by the long, slow process of nature, “should be infinitely better adapted to the most complex conditions of life, and should plainly bear the stamp of far higher workmanship.”

The years in which human selection has been practiced are miniscule when compared by geological time and the billions of years over which natural selection produced its species. It seems incongruent to believe that natural selection explains the origin of the species and to believe that human selection holds the hope for our future. Darwin was probably as right about our future as he was about our past.

* Warren Hochfeld has a BCom from Unisa, an MSc from The University of Pretoria, and is currently engaged in PhD research at The Department of Medical Genetics, Cambridge University.

 

September 2009