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Two anniversaries for the ages

February 14, 2009|By ALLAN POWELL

Throughout the year 2009, there will be many special events to recognize the impact of Charles Darwin and his evolutionary ideas on modern science and culture. Indeed, there are programs already in progress to celebrate Darwin's birth (Feb. 12, 1809 - 200 years) and the publication of his most famous book (The Origin of Species on Nov. 24, 1859 - 150 years). The public will be the beneficiary of some very interesting biography and some very illuminating biological science.

Darwin's life story is as fascinating as his ideas. Born to privilege, Darwin never had the need of an employer. His inheritances made it possible to live in comfort and pursue his studies as a naturalist in the quiet and peaceful surroundings on the family estate.

Darwin's father exerted a gentle, but steady, pressure on Charles to enter the ministry, but he preferred observing the work of nature to theological disputation. Nagging questions arose which would make it difficult, if not impossible, to have a successful career as a clergyman.

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At this period in time, both the clergy and scientists accepted the claim that the earth was about 6,000 years old. This age estimate was obtained from biblical interpretations and had been unquestioned for generations.

Darwin, using a gap in a mountain range in southern England, calculated that the earth had to be at least 306,662,000 years old. He estimated that erosion produced a loss of one-half inch every 100 years.

Another bothersome point of tension between accepted teaching and observation was the fixity of species. Again, there was general acceptance that all species were presently the carriers of the same physical form as that given on the day of creation. Darwin, an avid student of plant and animal domestication, saw directly the possibility of gradually altering the form of pigeons, dogs, horses and other species. Darwin, of course, proved to be correct on both counts.

By far, however, the most life-altering experience for Darwin came about in 1831 when he became the naturalist aboard HMS Beagle on a cruise that lasted nearly five years. When the ship dropped anchor at the Galapagos Islands, Darwin observed the most remarkable variations in many species - especially finches and tortoises. Here was an abundance of evidence supporting the mutability of species.

It was the genius of Darwin that provided the explanation for the role of variation in the struggle for survival which he called "natural selection." This dramatic insight came as a result of the chance reading of "An Essay on the Principle of Population," written by Thomas Malthus, a clergyman turned political economist. Malthus asserted that population growth was forever pressing on food supply, resulting in a struggle. Darwin recognized quickly that those species with favorable variations would benefit in this struggle and reproduce offspring that would perpetuate this variation.

Darwin anticipated antagonism to his conception of the mutability and origin of species and withheld the publication of his book for 20 years. His fears were justified and opposition to "Darwinism" has continued since it was introduced to the world at a meeting of the Linnean Society in July, 1858. The most vocal and sustained resistance to evolutionary biology exists in the United States.

This is a surprising development when one considers the additional scientific support for Darwinian thought. When the union of Gregor Mendel's discoveries in genetics and later advances in molecular biology are combined with the concept of natural selection in the "Neo-Darwinian synthesis," a more powerful, substantial understanding of evolution resulted.

In 1953, James Watson and Francis Crick announced their findings regarding the chemical structure of the genetic material, DNA. Genes were now considered to be "replicators" - that is, carriers of genetic messages which determine inherited traits. These "replicators," however, were not perfect carriers. There were changes called mutations or variations which eventuated in new species over long periods of time. Thus, Darwin has been given dramatic support for his early recognition of the importance of variation.

Darwin continued a process which began with Copernicus - the unseating of the earth and man as the special creation of a divine creator. It is entirely understandable that such a dramatic readjustment in status would be greeted with popular disdain.

But the combined impact of the findings of comparative anatomy, comparative embryology, paleontology and molecular biology hold at bay the hordes of biblical literalists who prefer self-imposed ignorance to evidence and reason.

This lone intellectual giant, by publishing one monumental book, has accomplished for biology what Albert Einstein has done for physics. Darwin has forever changed modern thought and it will not be successfully challenged by biblical literalism.

Allan Powell is professor emeritus of philosophy at Hagerstown Community College.

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