It has been 202 years since the birth of Darwin, and 152 years after the publication of his epoch making ‘Origin of the Species.’ Despite being recognized as the most influential theory of modern times and being accepted almost universally by scientists the world over, much opposition remains from Christians and Creationists to the very idea of evolution. “I am not descended from a monkey,” is a commonly heard refrain from the Darwin Doubters. In this article I shall briefly examine some of the overwhelming supporting evidence that allows us to say unequivocally that evolution is fact!
1. Anatomy. Comparing the physical qualities of living creatures, for example their skeletal systems, shows that humans have remarkable similarities with other mammals (we have five digits on the end of our extremities, a spinal column, sockets in the skull for two eyes etc). From this evidence alone anatomists could construct a family tree of living species, and as it happens, humans are most similar anatomically to the apes. This suggests that these species are related to each other somehow as Darwin predicted.
2. DNA. Darwin knew that humans and apes were related, but he lived before the discovery of DNA which would later provide dramatic evidence in support of his theory. Chimp and human DNA are a 98% match. How do we know? Heat up some human DNA to around 85 degrees Celsius and the double helix breaks apart. Let things cool down and each single helix will re-bond, because, like a hand and a glove the two sides match each other.
What happens if we add some chimp and human DNA together? Well, the chimp DNA continues to seek a bond with the human DNA (all DNA has the same A,C,G, T lettering which makes bonding possible). However, because of differences in the genetic sequence the bond is not so strong. Because the bond is not as good the hybrid DNA will break apart at a slightly lesser temperature than before. Now, if you tried mixing human DNA with rabbit DNA, the bond would be significantly weaker (we are not close relations with the rabbits), and the hybrid breaks apart at a much lower temperature. Experiments like this allow us to see that we humans are indeed most closely related genetically to chimps – a result which matches the expectation from anatomy!
3. Paleontology. Preserved fossils give us a great insight into the previous history of a given species and allow us to see evolution at work. These specimens can be anatomically compared with each other and placed on a family tree. Thanks to Radiometric dating techniques we can calculate the approximate age of rocks and therefore the fossils within them. Although specimens of ancient humans and chimps are rare, they do exist, and from them we can build up a picture of how humans and apes are related. The fossil record fits snugly with Darwin’s theory, and combined with DNA evidence we can say with certainty that the common ancestors of humans and chimps lived 5.5 million years ago.
Of course, in this article I have only painted the briefest of sketches of the scientific evidence that supports the theory of evolution. I hope that the Darwin doubters will be made aware of the overwhelming supporting evidence of evolution that comes from many diverse scientific disciples: Anatomy, animal breeding, bacteriology, biology, biochemistry, embryology, geology, genetics, taxonomy, zoology to name a few.
Actually, I feel it is a great shame that I have to write this piece on the advent of Darwin’s birthday. Despite the evidence, the creationists continue to insist on their own perverted vision of the ‘truth’ and I wouldn’t have to write this article if their views were not so prevalent. I hope that more and more people can come to understand the world, the inherent beauty of evolution, and will be able to wean themselves off their superstitious fables so that we can achieve a brighter future.
Happy birthday Darwin!