Friday, 22 January 2016

Charles Darwin's voyage on HMS Beagle

On 27th December 1831 HMS Beagle, a naval sloop that that had been converted to a brig by the addition of an extra mast, set sail from Plymouth, its five-year mission being not so much to explore new worlds as to conduct a survey of the coasts of South America for navigational purposes.

The young commander, Lieutenant Robert Fitzroy, was keen to take with him a companion who would be his equal in terms of intellectual ability and with whom he could therefore hold intelligent conversations about the discoveries that they might make. Enquiries were made and a young naturalist from Cambridge University was found who jumped at the chance to see the world at first hand instead of just reading about it in books.

This was 22-year-old Charles Darwin, who had become interested in the natural world when studying at Cambridge. He was also interested in geology, and this was initially his main interest during the Beagle voyage. Whenever the ship docked, which it often did for quite lengthy periods, Darwin would go ashore to collect samples of rocks and fossils, which would form the raw material for the three books on geology that he would write on his eventual return to England.

However, his focus changed completely when the ship reached the Galapagos Islands on the west coast of South America. Here, Darwin was fascinated by the animals and birds that he found there and he was struck by the fact that there were marked differences between the flora and fauna of individual islands.

However, it was not until he had returned to England and started to study his collected specimens in detail that the significance of these differences started him thinking about the reasons why they might have occurred. Why, for example, should the finches on one island have stronger bills than those on another island? Could the fact that the nuts growing on trees on the first island were tougher to open than those on the other island have anything to do with it? If so, how did this situation come to be as it was?

Darwin’s thought processes took a long time to mature into a general theory, and it was even longer before he was ready to publish what would be one of the most earth-shattering scientific works ever to get into print, namely “On the Origin of Species by Means of Natural Selection”, which only appeared in 1859, some 38 years after the Beagle set sail.

Darwin’s observations were the proof he needed for the belief that species evolved over time to fit the environment in which they found themselves. He was well aware that this did not fit with the commonly accepted view, based on the Book of Genesis, that all species were created, in their final form, by God on one of the days of Creation. By extension, this would also imply that Man was the product of evolution, although Darwin did go not this far in his original publication.

Because we now have tools at our disposal that Darwin did not have, in particular the knowledge of how genes and DNA are passed on and sometimes distorted from generation to generation, his theory is nothing like as shocking to modern readers as it was to Victorian England. Fortunately it is only a few religious nutcases, who prefer to believe ancient myths rather than the revelations of science, who now refuse to accept the truth of Darwin’s work, which had its genesis in the voyage that began in 1831.

© John Welford