Persuasive Essay: Evolution

The evolutionary theory is one of the most widely debated scientific theories. Many believe it to be the best explanation for how the living world with all its species developed. Others refuse to believe it and think of the theory as something dangerous. The theory itself states that the natural world, with all its different species, developed from simple organisms. This happened through gradual changes in the organisms’ genomes through natural selection, or ‘survival of the fittest’. This also means that all organisms are related, some more closely than others. Currently it is the only reasonable theory that explains how the natural world developed. Unlike others, it is not based on speculations or unsupported claims but on solid evidence. Evidence that can not be ignored.

All evidence that has been found points to one explanation. Archeologists have uncovered many fossil records. Through them science has been able to piece together the way in which the natural world developed from early unicellular organisms to the complex species we see today. For example, archeologists have found the remains of many early humanoids. Thanks to these finds, we now know how we looked millions of years ago and how we gradually developed to the modern human, the Homo Sapiens. These finds support the theory of evolution, because this is exactly what it states. Another good example of how the fossil record helps us understand evolution is the evolution of the horse (see appendix I). Due to the large amount of findings, we have an almost complete model of how the horse evolved. (se Even in our own bodies we find evidence of our primitive ancestors. The wisdom teeth we have are useless, but once our ancestors used them for chewing hard objects.

Another piece of evidence came about in the 20th century, when DNA was discovered. Analyzing DNA, a molecule which keeps an organism’s genetic code, gives scientists new possibilities. They can now compare the DNA of different species to see how they are related. The discovery of DNA once again confirmed evolution. We saw that all organisms are related to each other. For example, humans and chimpanzees have a 96% match in their DNA. This also proves another hypothesis, which states that chimps and humans have a common ancestor which lived several million years ago. This makes the two species closely related and is the reason for their similar DNA. The evolutionary theory is often incorrectly interpreted as saying that humans descended from apes. Many counter this by saying apes are still alive, while according to the theory, they should have died and been replaced by humans. As this argument is based on a misinterpretation of the evolutionary theory, it can not be seen as credible and is therefore not being discussed by scientists.

Many people who doubt evolution say that it has never been observed. This is in fact not true. Microevolution, small changes to species, has been observed both in laboratories and in nature. For instance, on the Galapagos islands, where Darwin also did his research, scientists have observed year-to-year evolution of birds. As the food supply changed, birds whose beaks were more suited to the given food survived and reproduced. Here we clearly see natural selection at work. Another observation was conducted in a laboratory. Scientists took a group of bacteria and added a lethal substance. Most bacteria died, but some had immunity. They survived and successfully reproduced. The next day the entire group was immune to the substance. They adapted to the poisonous environment through natural selection.

Considering the overwhelming amount of evidence supporting evolution and the nonexistence of evidence against it, one can conclude that it is indeed a valid scientific theory. The acceptance of evolution in the scientific community is almost unanimous. It has even gained some acceptance in religious circles, which previously refused to believe it. Pope John Paul II has said that “fresh knowledge leads to recognition of the theory of evolution as more than just a hypothesis.” But still, many people disagree with evolution. This is mostly caused by ignorance, fundamentalist beliefs, or wishful thinking. That is why, even 150 years after Darwin published his book, the debate continues with no end in sight.

References:

Scott, E.C. (2004). Evolution vs. Creationism: an Introduction. Los Angeles: University of California Press.

Ridley, M., & Quamman, D. (2009, February) The Darwin Bicentennial. National Geographic, 44-73DNA. (2009). Retrieved November 1, 2009 fromhttp://en.wikipedia.org/wiki/DNAO’Neil, D. (2009). Early Theories of Evolution: Evidence of Evolution Retrieved November 1, 2009 fromhttp://anthro.palomar.edu/evolve/evolve_3.htmEvolution of the Horse. (2009). Retrieved November 13, 2009 fromhttp://en.wikipedia.org/wiki/Evidence_of_common_descent#Evolution_of_the_horse