This spring sees the 50th anniversary of the publication of Watson and Crick’s theory for structure of DNA. (Their model was of course, possible only because of the laboratory analyses carried out by Maurice Wilkins and Rosalind Franklin.)
Discovery brings understanding and technique. Understanding and technique bring more discovery. And so it goes, on and on. An explosion of knowledge since 1953 has transformed the biological sciences. Most of us have benefited in our daily lives from large numbers of applications that have resulted, directly or indirectly, from work in molecular genetics: enzymes in biological washing powder, new disease therapies, improved milk production, better quality of fruit and vegetables on the supermarket shelves, genetic screening of unborn babies, DNA fingerprinting, understanding the processes that lead to cancer – the list is long enough to fill this column. Of course this has not been entirely philanthropic - massive profits have handsomely repaid the initial capital investments made in biotechnology. Computers have had a bearing on things too: the Human Genome Project would have been a bit difficult to do without them.
So what about the impact on Natural History? At the “big picture” level Darwinian evolution has been vindicated and consolidated. Perhaps the greatest paradox of all is that the amazing diversity of life forms that we so love to study are all founded on the same simple biochemical basis. We humans share the same genetic alphabet, the same humble beginnings, as cockroaches and oak trees, and even bacteria that live kilometres down in the crust of the Earth.
On a more practical level, techniques of molecular biology involving mitochondrial DNA are being used to trace the path of human evolution. For example it now seems that the Neanderthals were not our ancestors; they were a separate line that became extinct.
Studies of changes in DNA over time enable accurate setting of the geological clock. DNA hybridisation studies have helped to settle debates about how closely related different groups are, such as humans, chimpanzees and pandas. The family tree of the Dodo has been constructed (its nearest living relative is the Nicobar pigeon).
The use in systematics of DNA analysis of plant and animal organelles is resulting in reappraisal of relationships between species of many groups, and consequent reclassification. The orchids are a good example. Inconvenient this may be, but perhaps necessary: it has been suggested recently that double naming is responsible for overestimates of global biodiversity by as much as 44%.
With his “selfish gene” concept Richard Dawkins has provided a great deal of food for thought (and discussion, although the sociobiologists often seemed to grasp the wrong end of the stick). More important though are the interest and developments in genetic-level conservation as a complement to species conservation. This strengthens our awareness of the dangers of gene pool isolation and raises the importance of measures to counter fragmentation of habitats.
So I am wondering where things will go from here. It looks fairly certain that ‘Jurassic Park’-style reconstruction of fossil genomes is not a realistic prospect. What use will we make of knowing the complete human genome sequence? Better medicine will perhaps not be the only reward. Possibly the biggest prize will be computer reconstructions of evolution informed by comparison of the genomes of distantly related species leading to a better understanding of Man’s place in nature. However, I suspect that most people, including those whose health is improved with the help of new genetic knowledge may say that there is more to life than genomes.
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This is because the service was very infrequently used and it saves space on the server.
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I will decide whether there is sufficient demand for an alternative method.