Zimmer, Carl. "Agriculture Linked to DNA Changes in Ancient Europe." The New York Times. The New York Times, 23 Nov. 2015. Web. 29 Nov. 2015. <http://www.nytimes.com/2015/11/24/science/agriculture-linked-to-dna-changes-in-ancient-europe.html?rref=collection%2Fsectioncollection%2Fscience&action=click&contentCollection=science®ion=rank&module=package&version=highlights&contentPlacement=7&pgtype=sectionfront&_r=0>.
The article “Agriculture Linked to DNA changes in Ancient Europe” by Carl Zimmer explained the study of human genomes in Europe that helped trace changes to the human genome that occurred around the time of the agricultural revolution. The agricultural revolution brought changes in height, digestion, immune system and skin color that help create many of the varying traits we see today. Rasmus Nielsen, a geneticist at university of California Berkeley describes this study as a “time machine,” allowing us to gain a much vaster amount of evidence than the previous method of bone examination. These studies lacked information on when these changes occurred and whether these changes were due to natural selection or migration of people into Europe. In looking at DNA, scientists have discovered that Europe was full of hunter gatherers and that agriculture started with the emergence of a DNA resembling that from the Near East, leading scientists to conclude that people from the Near East migrated to Europe bringing farming with them. Dr. Reich, a geneticist at Harvard Medical School, analyzed 230 different human genomes from people living between 8,500 and 2,300 years ago. One important discovery was LCT, a gene aiding milk digestion which was made more common through natural selection after farming emerged. Another important discovery was a gene SLC22A4 which codes a protein to draw in the amino acid ergothioneine. This was essential to farmers who ate lots of wheat and other crops lacking ergothioneine, which this gene helped to better absorb. However, scientists have seen that variations in this gene can cause digestive disorders such as IBS, irritable bowel syndrome. Although many advances have been made, scientists are still looking for answers. This study was inconclusive about natural selection in height; there is an observed difference between the much taller people in the north of Europe compared to the shorter people in southern Europe.
This article is very important because it not only explains many parts of the past that were misunderstood, but it also gives us insight into variations today. In studying the DNA, we can see how the human genome has changed throughout time. This is important because we can see that what we are exposed to and what we eat changes the genome through natural selection. It is important to see that when agriculture was adopted, although genes were able to provide better absorption of nutrients, there were negative effects causing digestive problems. So although agriculture was an advancement in society and we were able to adapt, there are variations causing health problems. This was the first time that DNA was analyzed about how farming was brought to Europe and if scientists continue to do research on the changes to the human genome, we can track historic changes to the genome across the globe.
This article connected studies done on the genome and compared them to our prior knowledge. The article was very clear about the study performed by Dr. Reich and gave lots of information on genes that were discovered and how they furthered our knowledge of the human genome. However, I felt that the article could have been organized better. For example, the author put information about critiques of the study before the study. He also talked about other studies but didn’t give information on who performed them or even what was done to gain the information. However, the author was able to use the information gained from Dr. Reich’s study and compare it to our genome today. He made very good connections showing how natural selection has benefits in promoting genes that aid us, but can also cause harmful variations. Overall, it was a very interesting topic that although focuses on genomes from thousands of years ago, is still relevant today.
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