Friday, 27 February 2009

Darwin and Creationism

In the beginning God created...chemistry. I don't know about you but I find the extraordinary complexity of life that results from God's chemical processes truly awe inspiring, reminiscent in a way of entering a great cathedral or seeing a great work of art and wondering at the builders and originators of such beauty. Let us think for a moment about the extraordinary end product. When DNA was discovered and explained it seemed as if humanity had a relatively simple key to the processes of life yet with time we have found the story just gets more and more complicated. We have found that our genes are not simple codes for particular results, we have found that each gene can produce several proteins - an average of nearly six not one, that the same gene can perform different functions in different tissues at different times. We have found that the expression of each gene is itself controlled by complex processes, including methylation, from within the genome. We have found that whilst Darwin was mostly right that Lamarck was not completely wrong and that characteristics developed during a single life may, surprisingly, be passed on to our children.

Consider the curious case of human size. At times in history when people have had poor diets for several generations the population becomes smaller in stature. When diet improves, the average size does not spring back immediately but does so over several generations. I have a photograph of my grandfather, great grandfather and his father: each son taller than his father. In turn, my father was taller than his father, I was taller than my father and my son is taller than me. You can understand why this process makes evolutionary sense, reducing the risk of the improved food supply being temporary and ensuring babies in each generation are not too big for their mothers to give birth to. It seems, superficially, to go against our understanding of Darwin's ideas but complex processes of gene expression overlay the genetic code and control how it is manifested.

At every turn the complexity of life and its chemical processes expands. And all this is a natural process that follows from the chemistry of carbon, nitrogen and the other elements: when bundled together in certain circumstances they naturally start reacting and forming chains of molecules that join and break apart - stir, add water and heat gently for several billion years and you get us and everything around us. Amazing.

PS. There was a TV programme on Darwin recently that talked about Lakes Malawi and Tanganyika in Africa and how each had a huge variety of fish in different ecological niches that have evolved from the same single species over many millions of years. And what was wonderful was that very similar fish had evolved in each niche - as if evolution had run the same experiment twice and come up with much the same result. Amazing.

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