Charles Darwin's 203rd birth anniversary:

The scientist who changed the world

By Pramod DE SILVA

The name Charles Darwin is synonymous with the Theory of Evolution. Before Darwin proposed that life forms gradually evolved on the Earth, there was a general belief that all life had been ‘created’ by God or a similar higher power. Darwin literally turned the world upside down with his then controversial (it still is in some quarters) theory On The Origin of Species, the very title of his explosive treatise on life published in 1859.

On February 12, 2012, the world celebrates Darwin Day, in honour of the man who changed our view of life forever. The day commemorates Charles Robert Darwin’s birth anniversary (he was born on February 12, 1809).

Although more than 200 years have passed since his birth, his theories and ideas still resonate in the scientific and religious worlds, giving rise to a vigorous debate. Today, Darwin Day has also become an avenue to appreciate the advancement of human knowledge and the achievements of science and reason.

Darwin is among the most famous scientists who effected a fundamental shift in the way we think about our world. Ranked on par with Isaac Newton and Albert Einstein, Darwin made a discovery that changed our perception of the world around us. But for Darwin, it was not a flash of inspiration – it took years of careful observation of animal and plant species in their wild habitats to arrive at his conclusions.

Journey of discovery

The story of his journey of discovery begins on August 27, 1831. A young Darwin was on board the H.M.S. Beagle, as a naturalist. It was a complete circumnavigation of the Earth that took five years. Although Darwin was principally assigned the task of undertaking geological surveys, that did not diminish his curiosity for observing the natural world at work.

Darwin spent most of this time exploring on land: three years and three months on land, 18 months at sea. He explored varied landscapes from Azores to Galapagos to Falkland Islands during a journey that started from England and covered four continents including Australia. By the end of the journey, he had made a name as a naturalist, geologist and fossil collector.

The publication of the account of his journey – the Voyage of the Beagle – cemented his reputation. Incidentally, both his major works (Beagle and Origin of Species) have never been out of print.

Naturalist

This was the journey that planted the seed of evolution in his mind. “When on board H.M.S. ‘Beagle,’ as a naturalist, I was much struck with certain facts in the distribution of the inhabitants of South America, and in the geological relations of the present to the past inhabitants of that continent. These facts seemed to me to throw some light on the origin of species - that mystery of mysteries, as it has been called by one of our greatest philosophers,” he wrote later.

Puzzled by the geographical distribution of wildlife and fossils he collected on the voyage, Darwin began detailed investigations and in 1838 conceived his theory of natural selection. Having observed the sheer diversity of life in all the continents, he came to the inevitable conclusion that life has evolved through the process of natural selection. Although he discussed his ideas with several naturalists, he needed time for extensive research. He was writing his theory in 1858 when Alfred Russel Wallace sent him an essay which described the same idea, prompting him to make a joint announcement of the momentous discovery.

One long argument

A model of the HMS Beagle

His book On The Orgin of Species (full title: On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life) proved unexpectedly popular, with the entire stock of 1,250 copies sold when it went on sale on November 22, 1859. In the book, Darwin set out “one long argument” of detailed observations, inferences and consideration of anticipated objections.

His theory is simply stated in the introduction: “As many more individuals of each species are born than can possibly survive; and as, consequently, there is a frequently recurring struggle for existence, it follows that any being, if it vary, however, slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected. From the strong principle of inheritance, any selected variety will tend to propagate its new and modified form.”

This idea was later shortened to, and reflected in, the simple term “survival of the fittest”. In other words, weaker organisms may not survive if they cannot compete with the stronger ones. That is literally a fact of life for most animals and plants.

Popularity

Although Darwin himself did not use the word evolution until the sixth edition of his book was published, the word had gained popularity even earlier. Today, we have a clearer idea of how life evolved on Earth.

Complex life is a fairly recent phenomenon. The Earth is 4.6 billion years and the oldest organisms appeared around 3.8 billion years ago. According to the theory of evolution, it is from these simple organisms that all life on Earth ultimately derived.

The first multi-cellular organisms appeared only a billion years ago. Simple animals appeared around 600 million years ago. Mammals, perhaps the most successful group of species on Earth, are less than 200 million years. Dinosaurs went extinct around 65 million years ago. Humans, in the form of the genus Homo, came on the scene just 2.5 million years ago.

Although Darwin did not specifically mention the evolution of humans in his Origin of Species, just stating that “light will be thrown on the origin of man and his history”, he later wrote a separate book on the subject titled The Descent of Man. Although Darwin himself never popularised the idea of Man being descended from primates or apes per se, the idea quickly caught on, to the extent of newspaper cartoonists depicting (a bearded) Darwin as an ape.

Major discovery

One of the strongest factors in favour of evolution is the discovery of a large number of fossils of animals that lived millions of years ago. This shows that there has been a process of life on the planet. Another factor is the variation of species in the same family, a phenomenon described and catalogued by Darwin.

In one instance, he wrote: “These birds so closely allied to the Thenca of Chili is singular from existing as varieties or distinct species in the different islands - I have four specimens from as many islands - These will be found to be two or three varieties. - Each variety is constant in its own island.”

On the other hand, detractors say that “intelligent design” a.k.a creation, is the only way that complex organisms such as humans could have arisen. There is another question – if life sprang from amino acids and other ingredients in a ‘primordial soup’, does life exist on other planets which have similar conditions? Could life be unique to Earth or could life, even intelligent life, be commonplace in the vast universe? The debate about creation and evolution will rage on at least until these questions are answered.

Resurgence of interest

Following the 200th anniversary of Darwin’s birth, there is a resurgence of interest in his theories. Scientists including Richard Dawkins have staunchly defended the Theory of Evolution while debunking creationism. Despite opposition from certain religious and political groups, many schools in Western countries now teach about evolution.

Darwin left a legacy that only a few other scientists could match, even in the future. The Earth is constantly changing and so are its inhabitants. Evolution does not stand still, as Darwin pointed out. New species of flora and fauna are being discovered every day. With each new discovery, we can learn more about evolution itself. What will the species left on Earth look like in a million years? Only time - and evolution - will tell.