This article describes the accomplishments of Dr. Svante Pääbo and his colleagues who developed a highly sensitive new technique to sequence the genome of extinct humans known as Denisovans. The Denisovans and their “sister group,” the Neanderthals, are the closest extinct relatives of modern humans. Dr. Pääbo extracted DNA from less than 10 milligrams of the finger bone of a Denisovan fossil discovered in Denisova Cave in Southern Siberia. Using this small sample, Dr. Pääbo’s team was able to accurately map the complete DNA sequence of the Denisovans with such high level resolution that even small differences between the copies of genes that the individual inherited from its mother and father are distinguishable. The genome represents the first complete genome sequence of an extinct human group and is therefore a major advance in the study of extinct human forms. The level of detail in the genome is so precise that it has fewer inaccuracies than most genomes from present day humans. Biologists hope to be able to use the Denisovan genome to discover genetic changes that allowed the development of modern human culture and technology that enabled modern humans to leave Africa and travel around the world starting around 100,000 years ago.
I chose this article because I found it interesting that DNA could be extracted from a fossil. Also, it’s impressive how sufficient DNA could be extracted from a mere 10 milligram sample and how this DNA could then be used to obtain a complete genome of a human species that hasn’t existed for over 100,000 years. I also found it interesting that this genetic information could then be compared to the genome of modern day humans to demonstrate how humans have evolved over the last 100,000 years. Finally, I was fascinated by how this genetic information could be used to explain the development of modern human culture and technology.
I felt this article was insufficient because it was vague and provided very little specific information. The article didn’t explain how DNA was extracted from fossilized material or how the genome was mapped. Plus, the article didn’t explain how the new techniques used to obtain the more precise genetic mapping of the Denisovan genome compared to the prior, less precise method. Finally, the article didn’t explain what genes were mapped and how those genes are relevant to determining the evolution of Denisovan culture.
After reading this review, by Robby DeMeo, I felt rather intrigued and my interests urged me to find out more. The idea that small amounts of DNA can tell us so much about an organism's physical traits, is truly an extraordinary achievement. Technology is clearly becoming more efficient and more practical as proved by this review. Also, after reading the article myself, I have to agree that the quality of the article would've increased had the author explained the process behind extracting DNA from 100,000 year old fossils.
ReplyDeleteI do recommend to Robby, that in order to improve the credibility and the quality of the review, they add a bibliography that grants credit to the original author of the article, rather then just giving the link. Also, I wanted to add that in said article, it states that, "The finger bone was found in a layer which has been dated to between 50,000 and 30,000 years ago." This contradicts Robby's statement that says the Denisova have been extinct for over 100,000 years.
I was very impressed at the idea that the technology nowadays can make so much out of such a small sample of DNA that has aged for tens of thousands of years. I was unaware this was possible and am glad Robby noted that in his review due to it's significance.
I thought that Robby Demeo’s review of Denisovan genome was very interesting because it shows how useful paleontology is. First of all, I thought that Robby did a good job explaining the process through which the scientists examined the data. He also did an excellent job discussing the significance of this data. Robby explains how this is the first genome sequence of an extinct human group, so not only is it a major advancement in the study of paleontology, but this discovery is a significant contribution to other fields, like history. Robby made sure to mention the application of this discovery. He describes how the Denisovan genome can be used to discover the development of early human culture and technology that allowed humans to migrate from Africa approximately 100,000 years ago.
ReplyDeleteOne thing that Robby can improve on is defining some of the jargon, such as “genome.” Defining this term would definitely clarify the article. Another thing that I was wondering during the article was what exactly DNA shows. I thought that if Robby explained what DNA shows, the reader would have learned more.
I was really impressed by the potential of modern technology. Robby said that the scientists extracted DNA from less than 10 milligrams of the finger bone of a Denisovan fossil. Using this tiny amount, the scientists were able to map out the complete Denisovan genome, and they were even able to figure out the hereditary genes the individual possessed from its parents. I thought that this article reinforced the idea that our scientific knowledge is limited by how advanced our technology is; without their new precise process, the scientists would not have been able to sequence the genome.