By Bong Zhao Sheng and Kenneth Lee Ken Siong

Where do we come from? You may ask how life as advanced as us could have come from a humble microscopic cell. Well ladies and gentlemen, each and every one of us did it ourselves - in only 9 months! Some may dismiss evolution as “only a theory”. But if you deny evolution because it is just a theory, can you deny the existence of gravity? Can you also deny the fact that the earth rotates on its own axis and along its orbit around the sun? (Heliocentric theory)

We would like to start off by defining the word theory which, due to public misconception, has garnered much undeserved opposition to the facts of the Theory of Evolution, the central tenets of which is that all life on earth are developed from a common ancestor by natural selection. According to The American Heritage Dictionary of the English Language, the two relevant definitions of the word ‘theory’ are:

Definition 1: A set of statements or principles devised to explain a group of facts or phenomena, especially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena.
Definition 2: An assumption based on limited information or knowledge; a conjecture.

In the context of the ‘Theory of Evolution", many people erroneously assume it to fall under the latter definition without realizing that evolution is an undisputed fact supported by unequivocal evidence that is universally accepted by any respectable scientific community. Hence, in this article, we are going to present the evidences for evolution in human beings which we see every day but fail to see the significance behind it.

Firstly, since the majority of people reading this article are members of the medical fraternity, it is apt that we shall talk about bacterial resistance. As a result of genetic variation, some bacteria are more resistant than others to a particular antibiotic (just imagine a Bell normal distribution curve). Injudicious use of antibiotics creates an environment where the more resistant strains (which would die if you take antibiotics long enough) would survive a little better compared to the less resistant ones. Which bacteria are more likely to survive and pass their genes to the next generation of pathogens? The resistant bacteria will thrive and create a community of bacteria rendering the antibiotic useless. This is evolution on a microscopic scale and it can cause devastating healthcare problems with the emergence of MRSA, and Multi-Drug Resistant Tuberculosis.

Viruses mutate at an even more frigthening pace which is why HIV patient compliance to Highly Active Antiretroviral Therapy is essential and new flu vaccines are made every year. Furthermore, protozoa such as Plasmodium falciparum are also gaining resistance to chloroquine which is why we have to resort to alternatives like artesunate. Understanding evolution helps us solve biological problems that impact our lives.

Why do deadly genetic diseases such as Huntington’s chorea persist in our population? Shouldn’t natural selection remove such harmful genetic defects? The answer lies is the fact that Huntington’s chorea typically presents AFTER the reproductive age of humans, thus escaping natural selection. To stay one step ahead of pathogenic diseases, researchers must understand the evolutionary patterns of disease-causing organisms. To control hereditary diseases in people, researchers study the evolutionary histories of the disease-causing genes. In these ways, a knowledge of evolution can improve the quality of human life.

We also see it fit to talk about human anatomy which, to be frank, are not a ‘perfect form’ as opposed to the views of some ‘specio-centric’ people who claim otherwise. For example the wasteful track taken by the recurrent laryngeal nerve to innervate the larynx is an imperfect design. To the uninformed, it comes down as the vagus nerve tracking right next to the larynx but DOES NOT innervate it then. The right branch further descends into the thorax and loops around the right subclavian artery before ascending again to innervate the larynx while the left branch winds around the arch of aorta before doing the same thing (in the giraffe it means an extra 10-15 feet of nerve length!). It makes more sense if we understand that the vagus nerve in fish has branches that pass behind the gill arteries to innervate the last 3 gills. In the evolution of mammals, the neck stretched (for fish have no necks) and the gills disappeared.

The painful eruption of the wisdom teeth in our relatively small jaw are inherited from our ancestors who had use for them in chewing less refined food. The coccyx is a mere vestige from our ancestors who had tails to help them cling onto wood branches or for balance high above the canopy. The goose pimples we get when we are cold or are frightened are but vestiges of our ancestors who had thick fur coat to help trap air for insulation and increase their apparent body size to scare off threats.

Some may say we are dogmatic and closed-minded in our approach in clearing up the air of confusion, ignorance and apathy about evolution among the masses. We regret that there is much biological, paleontological and geological evidence for evolution that we cannot cover in 2 pages. But, have you ever looked up on the evidences for evolution before labeling it as only a theory with missing links and no evidences, and jump around in anger saying it is impossible for us to evolve from chimpanzees? (For the record, we do not evolve from chimpanzees, we only share the same ancestors as chimpanzees) If not, we would strongly suggest that you do for, to quote Charles Darwin, there is grandeur in this view of life, that from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.