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Nature and Society Editorial In Britain there is no doubt that the herring gull (a bird with silver-grey wing backs) and the lesser black-backed gull are distinct species; even the birds agree. But travel around the Arctic Circle and you find a ring of gulls, each able to breed with the neighbouring birds, in which birds change subtly from one area to the next. It is only where the ring meets up with its tail that the two species are distinct. Similarly in the mountains around the central valley of California there exists a ring of salamanders, with strongly blotched markings on the eastern side, getting plainer and plainer towards the western side of the arc. In that southern section, the two species are quite distinct. This year we celebrate the three hundredth birthday of Carl Linnaeus, the originator of the Linnaean system of classification of botanical and zoological specimens, with its distinctive names of genera and species. The classification was an enormous step forward for science, enabling the rapid development of botany, zoology and palaeontology. It is a basic tool of taxonomy, a study that is vital for pest control and quarantine (although, sadly, too few students elect to become taxonomists nowadays). Humans have always liked to classify and divide, and give names to categories. Babies are applauded when they learn to distinguish between dogs and cats, horses and cattle. But it is salutary to realise that it is only because all the intermediate species are extinct that such classification is possible. In the pilgrimage to the dawn of life that is told in Richard Dawkins’ The Ancestor’s Tale modern humans travel back through time to find their ancestors. Every other modern species is also seeking to find their ancestors. At our first rendezvous point humans join up with chimpanzees as we meet our most recent common ancestor, or concestor, in Dawkins’ terminology. Together we travel back until we meet the gorillas, as they and we find our concestor. And so it goes, joining with more distant relatives at each rendezvous. Animals eventually meet the plants, and all together go back to find the earliest forms of life on earth. Along the way many pilgrims tell tales and the whole is a varied and interesting exposition on evolution, well worth reading. Dawkins shows that all evidence from fossils, genetics and other branches of science agrees that life is a continuum, that evolution accounts for the amazing variety of life, and that this is wonderful and inspiring in its own right. From Linnaeus on, science has progressed by separating and categorising, and there is still need for this in many situations. At the same time it is now necessary to look at all the connections in the world, the blurring of borders between species, between sciences, between all parts of the environment. We can only appreciate our place in the world when we realise that there has been a continuum of species between ourselves and the chimpanzees, that we are first cousins, as it were. A few centuries ago it was reasonable to see humans as distinctly different from animals. Now whatever criterion we consider, tool use, tool making, intelligence, communication, empathy, even morality, we find that some other species exhibit something of the same feature. Dolphins, apes, elephants, birds, the more we study them, the more of what were considered to be uniquely human characteristics are to be found to extend to other species. This does not come as a surprise to anyone who has lived closely with animals. The surprise is that anyone could have thought differently, could have thought that animals had no intelligence, were just automatons with simply instinctive actions and reactions; that they had nothing in common with us. The blurring of borders between species is reflected in the blurring of boundaries between different areas of scientific study. In the eighteenth century men (and women) of science studied whatever took their fancy. Polymaths were common. As separate science disciplines developed, so specialisation became important. But learning more and more about less and less has limitations, and now we find that all sciences interlink and need cross-disciplinary teams. Darwin himself worked in biology and zoology, the broad domain of the naturalist. Even then it was obvious, if you care to think that way, that the interaction between biology and geology works both ways. The existence of limestone, coal and oil is sufficient to prove it. Now it is known that life has even had a role in the formation of some ore bodies. In this way the huge impact of humans on every aspect of the environment is part of the continuum of interaction between life and the physical world. The trouble is that we have developed unusually powerful ways of interacting with the environment. Because of our intelligence, we could take intelligent action to limit, or even reverse, the damage we are doing. Unfortunately there are people in influential positions who refuse to acknowledge the reality of what we are doing to the earth. Some of these same people refuse to believe that evolution has occurred. Given the overwhelming evidence for the age of the earth, and for the fact that evolution has occurred, this is amazing, and sad. Not only has evolution occurred, but it is occurring now; there are well documented cases of it amongst the finches of the Galapagos and in other places. Doctors coping with antibiotic resistance in bacteria, farmers experiencing increasing resistance to herbicides and pesticides in crop pests, are experiencing real time evolution. To deny this science is to deny ourselves the ability to understand a great deal about the earth. The more we understand where we have come from, and our kinship with all life on earth, the better our chance of avoiding the disasters our hubris looks set to engender. Jenny Wanless February - March 2007 edition accessible here Back to top ________________________________________________________________
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