SciTech

Celebrating Darwin’s 200th birthday

This past Feb. 12 marked not only the birthday of Abraham Lincoln, but also the bicentennial of Charles Robert Darwin. Charles Darwin introduced the theory of evolution to the world 150 years ago and changed the way people view biological sciences today.

Darwin was born on Feb. 12, 1809, in Shrewsbury, England, as the fifth of six children. According to an article on the Complete Works of Darwin Online, Darwin was encouraged to become a physician just like his father. However, due to his inability to watch surgeries, his father sent him to Christs College in Cambridge in hopes that he would become a parson. While at Cambridge, such influential minds as William Whewell and John Stevens Henslow helped spark Darwin’s interest in natural history.

Before Darwin’s revolutionary theory, several other theories had been proposed. Prior to the 19th century, the accepted theory for the extinction of species was catastrophism. This theory declared that species were periodically wiped out due to natural catastrophes and were then replaced with brand new species. Then, in the early 19th century, Jean-Baptiste Lamarck introduced a new, radical idea that stated that every new generation inherits some characteristics from its ancestors.

He advocated that the more an individual’s traits or organs are used, the more enhanced they become, and those that are not used become weakened or removed. These changes would then be passed on to their offspring. This, in a sense, set the stage for Darwin’s profound theory. However, Darwin was able to analyze samples that he collected to make a more thorough and convincing argument. Darwin’s most influential work came from his voyage on the H.M.S. Beagle. This expedition gave him an opportunity to study geological properties of the continents and collect a variety of living organisms and fossils from all over the world.

In his book, On the Origin of Species, Darwin recollected, “When on board H.M.S. ‘Beagle,’ as naturalist, I was much struck with certain facts in the distribution of the organic beings inhabiting South America, and in the geological relations of the present to the past inhabitants of that continent. These facts ... seemed to throw some light on the origin of species — that mystery of mysteries, as it has been called by one of our greatest philosophers.”

Upon his arrival back in England, Darwin conducted thorough research on the samples and notes he collected, and came to several theoretical conclusions. He believed that evolution did occur and that the change was gradual. He also recognized the primary mechanism of evolution as natural selection.

Natural selection refers to the idea that the more advantageous traits, which better help an organism survive and subsequently reproduce, are the ones that are passed on and adapted in future generations. He also realized that millions of current species arose from a single original life form through a branching process called “speciation.” The book, Charles Darwin: His Life Told in an Autobiographical Chapter, and in a Selected Series of his Published Letters, states that Darwin’s conclusions about speciation came from his studies in the Galapagos Islands, where he noticed that 13 species of finches had adapted to different environmental roles. This was puzzling to him because he only knew of one species of finch in South America, where they had presumably originated. These finches differed in beak shape, food source, and methods of obtaining food. Thus, he concluded that all these species of finches had originated from a common ancestor. Alfred Russel Wallace, working on islands in the South Pacific, came up with ideas similar to those of Darwin. After completing a paper about ideas that mirrored Darwin’s, Wallace sent his paper to Darwin, with whom he had initiated a correspondence. However, Darwin’s colleagues encouraged him to publish his own ideas and on July 1, 1859, On the Origin of Species by Means of Natural Selection was released. This provoked some outraged responses from the Church because the theory of evolution conflicted with the Church’s belief that all creatures were created by God. Darwin, however, avoided talking about the theological and sociological aspects of his work.

Darwin’s theory of evolution holds that variation among species occurs randomly and the survival and extinction of an organism depends on that organism’s ability to adapt to its environment. As stated on www.darwin-literature.com, his theory was based on five key observations. First, species have incredible fertility, so there are more offspring than adults in a species. Second, populations remain roughly the same size. Third, food resources are limited and may cause a struggle for survival among each organism. Fourth, variation is extensive in sexually reproducing species, and fifth, much of this variation is heritable. His concept of natural selection is that those with the “best” traits will be more likely to survive, and subsequently passed on to future generations.
Darwin’s work was well supported by some scientists, such as Thomas Huxley, while others were hesitant to believe that organisms could inexplicably pass special qualities to their offspring (which was later proved to be possible through genetic materials). Although Darwin’s theory of evolution is still questioned by people, it has established itself in the biological community, while research is still being conducted to further examine his theory.