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Today's Paper | December 23, 2024

Published 12 Feb, 2009 12:00am

The tree of life

I DO not watch the idiot box anymore; as an undergraduate I got my full share of it. What kept me glued to the television at that time were BBC`s amazing nature programmes produced by David Attenborough.

A 13-part nature special takes almost four years of hard work. He has done countless ones. After 50 years in the field he is still going strong — and is more forceful than ever about the fundamental importance of Darwin`s unifying theory of evolution.

Considerable pressure would be needed to persuade our TV channels to show Attenborough`s one-hour special, Charles Darwin and The Tree of Life, which BBC aired on Feb 1. This is part of a year-long series to mark the 200th anniversary of the publication of Darwin`s masterpiece The Origin of Species and his 150th birth anniversary. Going by clips on the Internet, the focus in the BBC programme appears to be the misconceptions that people have had about Darwin`s `dangerous` theory. Were it to be aired here, it would clear these.

Antagonism towards the theory is widespread in Darwin`s own country as well. A recent poll showed that a third of UK teachers want creationism (or its new incarnation, intelligent design — ID) to be taught alongside evolutionary theory. A significant source of resistance, other than from those who believe in the literal interpretation of Genesis, comes from the feeling of being devalued — a consequence of being lumped together with other primates — instead of being regarded as a superior creation. However, it is only when we see other living beings and ourselves as part of an interacting, mutually beneficial system that we can begin to reverse the environmental crisis which is a partial consequence of the views mentioned above.

The US has seen fundamentalist Christians trying to use the ID idea to introduce creationism in school science courses, to discredit the theo

ry of evolution. For them, the theory is little more than conjecture. But for the overwhelming number of biologists, it is as close to scientificfact as one can get.

The ID movement`s main claim is that there are things in the world — most notably life — which cannot be accounted for by known natural causes and that show features which, in any other context, could be attributed to intelligence. Living organisms are too complex to be explained by any natural, more precisely mindless, process. Instead, the design inherent in organisms can be accounted for only by invoking a designer.

According to Darwinism, evolution largely reflects the combined action of random mutation and natural selection. A random mutation in an organism, like random change in any finely tuned machine, is almost always bad. That`s why you don`t, screwdriver in hand, make arbitrary changes to the insides of your television. But, once in a great while, a random mutation in the DNA that makes up an organism`s genes slightly improves the function of some organ and thus the chances of the survival of the organism.

In a species whose eye amounts to nothing more than a primitive patch of light-sensitive cells, a mutation that causes this patch to fold into a cup shape might have a survival advantage. While the old type of organism can tell only if the lights are on, the new type can detect the direction of any source of light or shadow. Since shadows sometimes mean predators, that can be valuable information. The new, improved type of organism will, therefore, be more common in the next generation. That`s natural selection.

Repeated over billions of years, this process of incremental improvement should allow for the gradual emergence of organisms that are well adapted to their environments and that appear as though they were designed. By 1870, about a decade after The Origin of Species was published, nearly all biologists agreed that life had evolved, and by 1940 or so, most agreed that natural selection was a key force driving this evolution.

Until the 1970s, complicated mathematical and physical models were used to explain complex natural phenomena. It seemed reasonable to think that simple things had simple explanations and complex ones, such as humans, intricate ones. Complex systems that are invariably non-linear (i.e. effects are not proportional to causes) can now, in some cases, be explained by simple mathematical rules. Simple equations, often programmable on hand-held calculators, can generate the most complex visual and mathematical objects.

In Pakistan, fossil finds of whales in the past 15 years have shown how this largest of mammals, came from the sea, became an amphibian, evolved into a land animal and then returned to the sea. Some of the missing links, namely Ambulocetus (49 million years old) and Pakicetus (found in 2001) are now in our museums. See the video on www.tinyurl.com/bacn48 about the evolution of the whale, which ends with the description of the new find, Indohyus, in Kashmir on the Indian side. With such wonderful finds in the Indus River valley we should be working overtime to get our schoolchildren and the public enthused about paleontology and our past. The enthusiasm for dinosaurs in the West can be matched by that for our whales.

For this to happen, the Natural History Museum in Islamabad should stop treating its fossil treasures and other artifacts like a disjointed stamp collection. Darwin`s beautifully simple theory can bring it order. Today Darwin is not mentioned on its website and its public displays. This is not worthy of the Islamic civilisation that once pushed the frontiers of knowledge.

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