First Draft

When asked what evolution is, we may imagine primitive men like Australopithecus evolving into humans or dinosaurs which are believed to be ancestors of lizards or crocodiles. Most of us think of the evolution as a process that happened millions years ago. But this is a misconception we often make. In fact, evolution is still working today although the changes don’t appear significantly. Since nylon was invented in 1940s, nylon eating bacteria are nothing but new. The bacterium Pseudomonas can metabolize nylon due to certain enzymes it has. Surprisingly, however, same thing happens when you place non-nylon eating bacteria in an environment where the only type of food available is nylon. Whenever the experiment was tried, the bacteria would evolve until it was able to consume nylon. This example shows that most forms of life can adapt to their environment by evolving.

Then what about us; is human still evolving these days? My answer is yes: human being is also evolving and there are several evidences that support this.

Before I start my confirmation, let's take a look at the history of evolution theory and what 'Natural Selection' is. Many people regard Charles Darwin as father of the theory of evolution. He can be called in this way as he systematized evolution at his book ‘On the Origin of Species’. However, the concept of evolution is much older. Ancient Greek philosopher Anaximander believed that man naturally evolved from an early animal species. And in 1809, biologist Jean-Baptiste Lamarck asserted ‘The Theory of Use and Disuse’, insisting the transformation of one species into another. But it was Darwin who introduced the concept of natural selection and forever changed the concept of evolution.

Natural selection is a phenomenon that species is able to survive based on how well adapted it is to the environment. But natural selection doesn't generate new species. Mostly, the process simply allows a species to better adapt to its environment by changing the genetic makeup from one generation to the next. And the process is actually quite predictable. If a species lacks a certain trait which will allow it to survive, the species will die out or it will develop the missing trait.

Today, many researches on human evolution are proceeding to find out whether natural selection is still working to humanity. In 2007, Researchers of Utah University discovered genetic evidence that human evolution is speeding up and has not halted. 

"We used a new genomic technology to show that humans are evolving rapidly, and that the pace of change has accelerated a lot in the last 40,000 years, especially since the end of the Ice Age roughly 10,000 years ago," says research team leader Henry Harpending, a distinguished professor of anthropology at the University of Utah. He says there are provocative implications from the study.

"We aren't the same as people even 1,000 or 2,000 years ago. The dogma has been these are cultural fluctuations, but almost any Temperament trait you look at is under strong genetic influence. Human races are evolving away from each other. Genes are evolving fast in Europe, Asia and Africa, but almost all of these are unique to their continent of origin. We are getting less alike, not merging into a single, mixed humanity."

According to Harpending, the considerable increase in human population over the last 10,000 years has accelerated the occurrence of evolution. It’s because we were in new environments where we needed to adapt and with a larger population, more mutations came about. Therefore, thinking evolution is over due to its invisibility is obviously misconception.

Now let’s take a look at the several evidences that prove my argument. The fact that we can drink milk is important evidence that people are still evolving. When our ancestors made a living through hunting-gathering ways, most of humans’ ability to digest lactose shut down during their childhood. The gene regulated producing enzyme called ‘lactase’ which can digest lactose because human beings’ only available dairy food was mothers’ milk at that time. However, when they began to domesticate cows, sheep and goats, people could drink milk gained from those animals. But many new diseases also began to appear as our eating habits had changed. This problem was solved by creating genetic mutation that allowed them to digest lactose. According to experts of Broad Institute of MIT, this mutation is presumed to appear 7,500 years ago in Europe. People with the genetic mutation were able to spread their genes, so now more than 95 percent of Northern European people carry genetic mutation which can digest milk.

 The fact that we are losing wisdom teeth is other evidence. Most people think of wisdom teeth as an irritating medical annoyance. Interestingly, however, the reason why wisdom teeth grow much later than other teeth has something to do with evolution. Our ancestors had much larger jaws than we do. It must have helped them to chew tougher foods like roots and nuts and tore meat apart. However, nowadays we can utilize utensils like forks and knives to cut food. Also we have plenty of foods which are much softer and easier to chew. Therefore, jaws of modern humans became too small to contain them without disrupting the other teeth. Like appendix which lost its original function as we quit eating uncooked food, wisdom teeth have become trace of our evolution. In fact, 35 percent of us are already born without wisdom teeth. Some are even born with just one, two or three wisdom teeth. It’s no surprise because evolution tends to eliminate a trait to save on the needless energy expenditure it takes to develop it when that trait is no longer necessary.

Human brains are shrinking due to the evolution. According to John Hawks, professor of University of Wisconsin–Madison, study of our genome has revealed that hundreds of our genes show evidence of changes during the 10,000 years of human evolution. He also mentioned that particularly our brains are evolving recently. He said that our brains have actually been shrinking, not growing, over the last 5,000 years in comparison to archaeological data discovered in Europe, China and Australia. The average volume of the human brain has decreased from 1,350 cubic centimeters to 1,200 cubic centimeters. Professor Hawks suspected that shrinkage of human brains is related with the change of our lifestyle. Unlike in hunter-gather society, we now live in huge society. We can rely on others in many parts of our lives, allowing us to work together to solve problems. Therefore, smaller space would be enough for brains to take up. Also smaller brains are more efficient as it can be rewired to work faster.

Evolution also made us stronger to endure diseases. You can see the most obvious evidence in mutation against malaria. Sickle cell anemia is one of examples of defenses against malaria. Sickle cell anemia is a disorder which deforms red blood cells into sickle shapes. It impairs blood flow and tissues. Surprisingly, this malady can also prevent the malaria parasite from infesting blood cells. Sickle cell is best known in Africa, but there is also an India-Pakistan variant that seems to have evolved very recently. Dr. Ian Barnes from the School of Biological Sciences at Royal Holloway says that living in cities has also produced a genetic variant that allows us to be more resistant to diseases like tuberculosis and leprosy. 

Recently Sir David Attenborough, the famous naturalist, said that humans have stopped evolving physically and genetically, during the interview with week's Radio Times.

“We stopped natural selection as soon as we started being able to rear 90-95% of our babies that are born. We are the only species to have put a halt to natural selection, of its own free will, as it were.”

His argument seems plausible at first glance as we have achieved astonishing advancement in reducing infant mortality and in combating many diseases. However, children’s survival is not assured as Attenborough said and it is not consistent across the world. Still, a lot of people cannot have basic healthcare and continue to die because of diseases and malnutrition. Moreover, even if we do reach the point of “being able to rear 90-95% of babies that are born”, that will only counter one of the conditions necessary for natural selection.

Attenborough is right in that natural selection requires variation. It needs some people to prosper more than others. So the improved survival prospects around the world might have decreased the potential for natural selection to work in those who are not threatened by natural tragedies. However, it may sound ironically, natural selection doesn't really care about survival. As I said, natural selection does help species to survive. But is every natural selection related with survival? Natural selection only helps the emergence of gadgets that can solve the problems efficiently. What it is ultimately interested in is sending variations to next generations in order to increase effectiveness. Therefore the argument that our natural selection has stopped due to our increased survival prospects is flawed.

In fact, humanity has not abandoned its ability to make genetic variation. The human genome shows that recent population explosion made more variations within the last 200 generations. Thus, we may be evolving faster than ever before. Among them are mutations like lactose tolerance, smaller jaws and carrying the sickle-cell allele.

Until now, evolution and civilization was considered as discrete thing. Human developed civilization after the process of evolution and society kept changing in that civilization was a universal thought. However, many scientific evidences prove that humans are still evolving and our evolution is progressing faster than ever before due to the rapid development of civilization. Evolution is not a story of hunched primitive man anymore. It is story of us. Theory of evolution is still a primary object of study to biologists and even today groundbreaking hypothesis is ready to emerge. As we have seen how human being has recently adapted to new surroundings, I believe that we can somewhat predict how we will evolve in future. This will not only give enjoyment of imagining future of humanity but also make us to prepare for upcoming future.