Tomorrow marks the 200th birthday of Charles Darwin and what is known as Darwin Day. This is not an official celebration but you will find scientists, TV stations, newspapers and other channels around the world publishing articles and programmes on Darwin and his work.
So what exactly is the point of Darwin Day? It's a good idea to start with what Darwin Day is not. It's not like Christmas Day when Christians celebrate the birth of their saviour, a messiah who brought them, they think, the ultimate truth. Not everything Darwin wrote was correct. He got some things wrong. There were other things, such as the existence of DNA, that would only be revealed by later research. His work provides a foundation for modern biology but has been much refined and built upon.
Some of the ideas that Darwin used to forge his theory of Evolution through Natural Selection were even already "in the air" among naturalists long before Darwin. The idea that life might be ancient and that living things change over time already had some currency but these ideas were loose and ill-formed.
Darwin's greatness lies in part in the example he sets us about the application of the scientific method. He was incredibly attentive to detailed observation and experiment, to the accumulation of evidence and in the way he linked evidence to conclusions. He was able to marshall facts that at first seemed overwhelmingly complex and to forge from them a coherent explanatory theory. For the first time there was a theory about the processes that governed life on this Earth.
The impact of Darwin's theory of Evolution on our conception of ourselves can not be overstated. Before Darwin people thought of the Human race as somehow divinely distinct and separated from the other life on this planet. After Darwin this view has no credibility except among more fundamental christian sects mostly in the US and with some Islamic fundamentalists. Even the Catholic Church has stated without quibble that it accepts the scientific merit of the theory of evolution. One Pope described it with understatement as "more than a hypothesis".
Darwin Day then is in part about celebrating the life of a great scientist. But it is much more than that. It is about celebrating the opening of our eyes to the reality of our existence on this planet. We were forged in the ancient fires of this world and we come from the lowly and less complex life which once lived here. You and I each have a long line of ancestry that goes back through to these ancient life forms. We are all connected in this most profound way.
The true meaning of Darwin Day is to remind us of this truth that Darwin laid before us - that all life comes from the same root and that we owe our existence and abilities to lines of ancestors that stretch back down the tree of life and through the incredible age of the Earth. This is an immense and awe inspiring truth and Darwin Day reminds us of this.