20721 정태준: 10월 2014

2014년 10월 27일 월요일

2014년 10월 26일 일요일

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.

2014년 10월 21일 화요일

Week 10 Conclusion

2014년 10월 19일 일요일

Week 9 Refutation and Concession

1. What is my thesis?
Humans are still evolving.

2. What is the opposite position?
Humans have stopped evolving in physical terms.

3. What arguments can I anticipate?
Well-known naturalist Sir David Attenborough claimed that humans have stopped evolving as humans have now escaped from interference of nature.

4. How will I counter those arguments?

Their arguments say that is not working anymore because of improved survival prospect. However, not all adaptations are related with survival. It’s mostly related with matter of efficiency. Also there are many evidences which prove humans are still evolving as I mentioned in confirmation.

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

2014년 10월 18일 토요일

Research 4

Research 4: Sir David Attenborough is wrong – humans are still evolving

Source:
Sir David Attenborough is wrong – humans are still evolving

http://www.theguardian.com/commentisfree/2013/sep/10/david-attenborough-humans-still-evolving

My Topic:
Humans are still evolving.

What I hope to learn from this source:
I want to know what is opponents' argument and there evidence and how people refute their idea.

Notes:

1. David Attenborough: He believes that natural selection is halted as our survival prospects have increased. His idea is that natural selection occurs when we struggle for survival. However, as our life became much safer than that of our ancestors, he says we don't evolve anymore.

2. Author’s Refutation: The author(Ian Rickard) refutes Attenborough’s opinion in that natural selection’s ultimate goal is not a survival of the species. According to him, what natural selection interested in is the number of descendants an individual produces who can then pass on their genes. So we did not stop evolving just because we now live in safer environment.

Final Thoughts:

I will use this for my refutation. I think Attenborough’s opinion represents the other’s, who believe that humans no longer evolve. However, I’ll prove that they are having wrong ideas and give them reason why we must believe that human being is still evolving.

2014년 10월 11일 토요일

Week 8 Confirmation

1. What is my thesis?

Humans are still evolving.

2. What types of source am I using to defend my thesis?

I am using experts’ opinions and relevant science articles.

3. Are my arguments mostly based on evidence, logic or emotion?
My arguments are mostly evidence. I have quotes from famous people, and a good example. There are no emotional appeals but I don't think those would be useful. I’m going to look for more statistical evidences.

Human brains are shrinking due to the evolution. According to John Hawkes, professor of University of Wisconsin–Madison, study of our genome has revealed that hundreds of our genes show evidence of changes during the past 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 Hawkes 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 makes us become stronger to diseases. You can see the most obvious evidence on mutation against malaria. Since the disease often targets humans early in life, there was a strong pressure to evolve defenses from malaria — any genetic factor that confers resistance against it would give descendents a chance to have offspring, while those without such protection were more likely to not reproduce. There are lots of examples of defenses against malaria. Sickle cell anemia is the best known —the disorder deforms red blood cells into sickle shapes, which can impair blood flow, thus damaging tissues, this malformation also prevents the malaria parasite from infesting blood cells. Although sickle cell is best known in Africa, there is also an India-Pakistan variant of it that seems to have evolved separately,” Hawks explained. “Both variants have evolved very recently, in the last three or four thousand years, and in that time have risen to as much as 10 to 15 percent of the populations. That’s pretty rapid change. Living in cities has produced a genetic variant that allows us to be more resistant to diseases like tuberculosis and leprosy. "This seems to be an elegant example of evolution in action," says Dr. Ian Barnes from the School of Biological Sciences at Royal Holloway. "It flags up the importance of a very recent aspect of our evolution as a species, the development of cities as a selective force."

Originally, we all had brown eyes. But about 10,000 years ago, someone who lived near the Black Sea developed a genetic mutation that turned brown eyes blue. While the reason blue eyes have persisted remains a bit of a mystery, one theory is that they act as a sort of paternity test. “There is strong evolutionary pressure for a man not to invest his paternal resources in another man’s child,” says the lead author of a study on the development of our baby blues. Because it is virtually impossible for two blue-eyed mates to create a brown-eyed baby, our blue-eyed male ancestors may have sought out blue-eyed mates as a way of ensuring fidelity. This would partially explain why, in a recent study, blue-eyed men rated blue-eyed women as more attractive compared to brown-eyed women, whereas females and brown-eyed men expressed no preference.

Research 3

Research 3: Are Humans Evolving Faster?

Source:
Are Humans Evolving Faster?

http://unews.utah.edu/old/p/120607-1.html

My Topic:
Humans are still evolving.

What I hope to learn from this source:
I want to find facts that might help me develop my topic, or new sources that will help refine my topic.

Notes:

1. Utah University Research: In 2007, Researchers of Utah University discovered that human evolution is proceeding. They even found genetic evidence which proves human evolution is speeding up.

2. Henry Harpending: Research team leader Henry Harpending presumes that this phenomenon is due to the rapid change of environment where we have to adapt a lot of new things. He believes large population we live together these days also affects rapid evolution.

Final Thoughts:

I would like to add this in Narration. It would like to inform this to readers because it can strengthen my thesis. Also I'll quote Henry Harpending's word for the same reason. I will use summarized one at refutaion and concession to refute opposition's argument.

2014년 10월 10일 금요일

Research 2

Research 2: 5 Signs Humans Are Still Evolving

Source:
5 Signs Humans Are Still Evolving

http://mentalfloss.com/article/30795/5-signs-humans-are-still-evolving

1. We can drink milk: We can tolerate lactose due to the evolution. Since humans began to domesticated cows, goats and sheep, we got genetic mutation which can tolerate lactose though we grow up.

2. We are losing out wisdom teeth: Wisdom teeth lost its original function because of our physical change. Our ancestors used to have bigger jaws as their foods were much tougher than what we eat today. Today we can eat softer foods so our jaws became smaller. That’s why we are losing out wisdom teeth – no room for them.

3. Shrinkage of Brain: Our brains are shrinking because of big society where we can now rely on others in many parts of our lives. Some say that shrinking of brain really means we are getting dumber. Some say it’s because smaller brain is more efficient.

4. We are resisting diseases: We are getting stronger to resist diseases like malaria. Also people living in cities are becoming more resistant diseases like tuberculosis and leprosy.

Final Thoughts:

I will use these four to write my confirmation. I think four is enough. I will not use the information about getting blue eyes because it is little bit abstract. It would be better if there were several statistics. I’m going to look for it.

Research 1

Research 1: 10 Examples of Natural Selection

Source:
10 Examples of Natural Selection
http://www.discovery.com/tv-shows/curiosity/topics/10-examples-natural-selection.htm

My Topic:
Humans are still evolving.

What I hope to learn from this source:
I want to find either facts that might help me develop my topic, or new sources that will help refine my topic. I want to look for something interesting.

Notes:

1. Nylon eating bacteria: What a surprise! I never heard of any organism that eats nylon. Even nylon is a man-made fabric. The bacterium Pseudomonas can metabolize nylon due to its special enzyme. However, other bacteria also evolved to metabolize nylon when they were put in places where they can only eat nylon. As I can see from this example, organism can adapt any foods that environment gives.

2. Humans: Humans are still experiencing evolution. The fact that we are the only mammal that can tolerate lactose though we grow up is a result of evolution. Also gene mutation made human being stronger to endure diseases like malaria.

3. History of theory of evolution: Darwin is called as ‘Father of theory of evolution’. But Darwin is not the first one who thought of evolution. (Greek philosopher Anaximander, Jean-Baptiste Lamarck)

4. Natural selection: It does not make new species but can improve species’ survival by helping them to adapt changed environment.

Final Thoughts:

I’ll use the information about nylon eating bacteria in introduction because it is interesting enough to grab readers’ attention.(In my opinion) I should have to look for more information related with recent human evolution. Information I found (about lactose and malaria) is good but not sufficient. I would like to use history of theory of evolution and information about natural selection in narration part as it can give good information to people. Also they are quite interesting.