Evolution and the Failure of Creationism

The court room is silent as judge Raulston reads his decision. Unfortunately, he rules against the defense, and John Scopes is fined $100. However, in the war of public opinion, Scopes had won trial, which would infamously become known as the Scopes Monkey Trial, named after the biology teacher, John Scopes, who had the audacity to teach evolution in his high school science class. The year was 1925, but evolution is still being argued about today. In this article, I hope to give a brief summary of what evolution actually is, and the lines of evidence in favor of it. Along the way, I will answer objections that many deniers of evolution make. I will then conclude with implications for society as a whole.

Evolution?

So what is this evolution all these smart intellectual type scientists speak of? Well, the answer is not as complicated as one may initially think. In fact, we have all seen the effects of evolution directly in our lives with antibiotics and breeding animals. But more on that later. Evolution can be defined as “ the cumulative changes that occur in a population over time. These changes are produced at the genetic level as organisms' genes mutate and/or recombine in different ways during reproduction and are passed on to future generations. Sometimes, individuals inherit new characteristics that give them a survival and reproductive advantage in their local environments; these characteristics tend to increase in frequency in the population, while those that are disadvantageous decrease in frequency. This process of differential survival and reproduction is known as natural selection. Non-genetic changes that occur during an organism's life span, such as increases in muscle mass due to exercise and diet, cannot be passed on to the next generation and are not examples of evolution. “ This complicated definition is simply saying that genetic changes over time cause individuals to change also.

Macro and Micro

Speaking of time, there is another distinction often made, and that is between micro and macroevolution. What is the difference? Microevolution is a “slight genetic change over a few generations in a population.” It does NOT result in a new species. Macroevolution, on the other hand, is “the slow progressive change of one species into the next.” Therefore, the only difference between these is time itself, one being short term, and the other being longer. Creationists often claim to believe in “micro” but not “macro.” As can be seen by the actual scientific definitions, any individual who asserts such nonsense is proving that they do not understand what evolution is.

How Evolution Works

The next question is how exactly evolution occurs. It has four basic mechanisms: genetic mutations, geographical changes, genetic drift, and natural selection. A genetic mutation is “a change in DNA, the hereditary material of life,” and can be “beneficial, neutral, or harmful for the organism, but mutations do not "try" to supply what the organism ‘needs.’ In this respect, mutations are random — whether a particular mutation happens or not is unrelated to how useful that mutation would be.” Migration is when one species moves from one population to another. So for example, “Some individuals from a population of brown beetles might have joined a population of green beetles. That would make the genes for brown beetles more frequent in the green beetle population.”

Genetic drift is “Random changes in the gene frequencies of a population from generation to generation.” To return to the beetle example, “Imagine that in one generation, two brown beetles happened to have four offspring survive to reproduce. Several green beetles were killed when someone stepped on them and had no offspring. The next generation would have a few more brown beetles than the previous generation—but just by chance. These chance changes from generation to generation are known as genetic drift.” The gene frequency of the brown beetles increased just by the coincidence that the green beetles died.

And finally, natural selection is slightly misleading, for it sounds as though nature is “selecting” certain groups. However, again random chance it the key. It is the “differential survival or reproduction of different genotypes in a population leading to changes in the gene frequencies of a population.” So if one set of genes gives flies a greenish color, and another makes them black, the black flies are much more likely to be spotted by birds. Therefore, the green fly's babies are much more likely to survive, and end up being “naturally selected.”

Just a "Theory?"

Staying on the topic of misunderstood scientific jargon, there is another problem that many have with regards to evolution, and that is what the definition of a scientific theory is. Looking up a theory in the regular dictionary does no good because it will simply report on whatever the common usage of the time is. Scientists have a specific meaning when they use theory, and it is just a problem of communication when many members of the population misunderstand what scientists are actually saying. A scientific theory is defined as “a rigorously tested statement of general principles that explains observable and recorded aspects of the world. A scientific theory therefore describes a higher level of understanding that ties "facts" together. A scientific theory stands until proven wrong -- it is never proven correct.” It can be verified until the end of time, but if any observations arise that falsify the theory, it is rejected at that point. So what is the evidence for this “theory” of evolution?

Evidence for Evolution

There are four lines of evidence: the fossil record, similarities among related organisms (homologies), the locations of different species, and genetic changes that have been observed over time. The fossil record has preserved a plethora of transitional fossils (which are intermediate organisms that gradually change as the animal or planet gets closer to its current form) proving that evolution has occurred. Here is a short list outlining some of the transitional forms early humans took: Australopithecus ramidus, Australopithecus afarensis, Australopithecus africanus, Homo habilis, Homo erectus, Archaic Homo sapiens, and H. sapiens sapiens. Clearly, the fossil record does show transitional forms. Creationists are just factually incorrect when they claim transitional fossils do not exist.

“Similar characteristics due to relatedness are known as homologies.” Evolution predicts that if species are related, they will share similar molecular and physical structures. And tetrapods are a perfect example, with birds, lizards, rabbits, and frogs all being related and with "forelimbs all share the same set of bones - the humerus, the radius, and the ulna."I find it to be quite interesting that species that seem so far apart are actually kin!

Geography also plays a role. If evolution is true, one would expect to find distinct species that are isolated from others based on their location. And one example of this evidence is that “before humans arrived 60-40,000 years ago, Australia had more than 100 species of kangaroos, koalas, and other marsupials but none (my emphasis) of the more advanced terrestrial placental mammals such as dogs, cats, bears, horses. Land mammals were entirely absent from the even more isolated islands that make up Hawaii and New Zealand. Each of these places had a great number of plant, insect, and bird species that were found nowhere else in the world.”

Finally, to return to the claim that humans have observed evolution in their own lifetime, bacteria and selective breeding are both modern day examples. It is widely known that bacteria can become resistant to antibiotics. And why is this? “When a lethal dose of antibiotic is added, there will be a mass die-off. However, a few of the bacteria usually are immune and survive. The next generation is mostly immune because they have inherited immunity from the survivors. That is the case with the purple bacteria in the Petri dishes shown below--the bacteria population has evolved. “ And selective breeding has given us domesticated dogs and some forms of houseplants.

Conclusion

So with the evidence for evolution being overwhelming, creationists have no rational case to make as to why it is not the best explanation for the variety of life we see on earth. It is not “just a theory,” and there are a cornucopia of transitional fossils, if they are just looked for. Instead of being intellectually honest, conservative politicians like Michelle Bachmann say we need to teach “both sides” of the debate, when in reality there is no other side. The only questions scientists debate are the processes of evolution, not that it actually occurred. Any presidential candidate who denies that evolution occurred, even with the mountain of evidence staring them in the face, shows they are either unable to rationally assess evidence and therefore should not be president, or are so willing to play politics they are willing to deny one of the most accepted scientific theories of all time just to garner votes. Either way, they do not deserve the support of any rational human being.