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HUMAN ARE STILL EVOLVING

Nguồn: Hashem Al-Ghaili

Many people think of evolution as a thing of the past. Something that started billions of years ago with single-cell organisms and ended with modern humans, but that couldn’t be further from the truth! Contrary to popular belief, humans haven’t stopped evolving. It is still happening and we are actively changing. And it’s possible that it’s happening faster than ever. Let’s take a look on the scientific evidence for this.

Let start with the human eye: Not the inner workings of the eye, though the evolutionary history there is fascinating. Let look at the color! Roughly 17% of the world population has blue eyes. That may not sound like a lot. But 10.000 years ago people of blue eyes were unheard of. Researchers believe that blue eyes came from a mutation in a single ancestor between 6.000 – 10.000 years ago. When you recognized that modern humans have existed much longer than that, it’s clear that evolution couldn’t have stopped with the rise of the humanity.

What about the brain? We think pretty highly about brains, but it turns out our brains have actually been shrinking over last 30.000 years. The average volume of the human brain has been decreased from 1500 cubic centimeters to 1350 cubic centimeters. That’s a reduction in size of about 10%!

What about our teeth? Wisdom teeth are the last morals in our mouths, and they were helpful in the early ancestors who ate tough, uncooked that wore away their teeth. Today, thanks to cooking and cutlery, our foods become softer and easier to chew. As a result, our jaws have become much smaller and there is just not enough room left for wisdom teeth anymore. According to some estimate, 35% of population is born without wisdom teeth, and some researchers believe that wisdom teeth will eventually disappear altogether. Those of us who still grow wisdom teeth often have to have them surgically removed. As evolution continues, it’s likely that the humans of the future will not have to deal with not have to deal with this painful struggle. Lucky them!

We can even see traces of human evolution in our lungs! Well, some of us. People who are native to Tibet are able to live in Himalayan Mountains with low oxygen level, but it’s not that they’re just … used to it. Living with low oxygen levels over several generations has led to mutations in their genes. As a result of genetic evolution, Tibetan people’s blood produces more of oxygen-transporting protein called hemoglobin.

What is possibly more fascinating than all of this is that evolution in humans appears to be speeding up. In past 5000 years, humans have evolved up to 100 times more quickly than at any time in 6 million years. The widespread assumption that humans evolution has slowed down because we’ve conquered nature is absolutely not true. We haven’t conquered nature at all, we simply have developed ways to curate our surroundings and experiences our liking.

Researchers have analysed data from the international Haplotype Map and analysed genetic markers in 270 people from four groups, Han Chinese, Japanese, Africa’s Yoruba people, and northern European. They found that at least 7% of human genes have undergone recent revolution. The changes include lighter skin and blue eyes in northern Europe, and partial resistance to diseases such as malaria among some African populations. Some of the changes were traced back to just 5000 thousand years ago and today they are in 30 to 40% of people because they are evolutionary advantage. For example, many Chinese and African cannot digest lactose and milk. But across Europe, lactose tolerance gene is now widespread. Another reason we are seeing an increase in our evolutionary speed in the rise of global population. As the population grows, humans are reproducing more frequently, and that means mutations are able to be passed on.

Evolution in humans probably won’t stop anytime soon. In fact, it will likely continue on until humans become something else entirely. As Carl Sagan put it, “It will not be we who reach Alpha Centauri and the other nearby stars. It will be a species very much like us, but with more of our strengths and fewer our weaknesses.”

Vocabulary:

  • Evolution (noun): /ˌev.əˈluː.ʃən/: the way in which living things change and develop over millions of years
  • Organism (noun): /ˈɔː.ɡən.ɪ.zəm/: a single living plant, animal,virus, etc.:
  • Mutation (noun): /mjuːˈteɪ.ʃən/ :the way in which genes change and produce permanent differences:
  • Ancestor (noun): /ˈæn.ses.tər/: a person related to you who lived a long time ago:
  • Conquer (verb): /ˈkɒŋ.kər/:  to take control or possession of foreign land, or a group of people, by force:
  • Haplotype: /ˈhapləʊtʌɪp/: a combination of closely linked DNA sequences on a single chromosome.
  • Lactose (noun) /ˈlaktəʊz/: A sugar present in milk

 

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