Varun Aysola
Author: Geoff Brumfiel
Date: October 22, 2014
Summary:
This article is about how researchers found the femur of a human that lived 45,000 years ago in Siberia. A local paleontologist found the bone on the Irtysh River, which was a strange place to live 45,000 years ago, as the temperature was frigid. The paleontologist handed it to the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, where they were so surprised by the age that they dated it twice. After sequencing the genome of the femur, Svante Pääbo, the director of the Max Planck Institute for Evolutionary Anthropology, decided that it was twice as old as the next oldest genome that had been sequenced. This provided insight as to early human life outside of Africa. Modern humans evolved 200,000 years ago in Africa, and left the continent 100,000 years later. However, it it known that humans were already living in Europe and Asia by then, such as the Neanderthals. The Siberian man's DNA contained a little of the Neanderthals' DNA, indicating that he was descended from the Neanderthals.
Relevance:
The article is relevant to the Honors Biology curriculum because it has to do with macromolecules. A genome is the complete set of genes in an organism. The researchers sequenced the genome of the 45,000 year-old Siberian man's femur (leg-bone). When someone sequences a genome, they name the order of the different types of nucleotides in the DNA. There are 4 types of nucleotides in DNA, adenine, thymine, guanine, and cytosine. DNA stores the organism's genetic information in these nucleotides. Nucleotides are the subunits of nucleic acids.which are one of the four macromolecules, which we learned in class. By sequencing the Siberian man's DNA, the scientists were able to figure out that his ancestors were Neanderthals.
How did Scientists use the DNA from just the femur bone, and trace is back to 45,000 years ago? How did they know it was a Neanderthal?
ReplyDeleteThe DNA in the bone is representative if the entire organism. It is not clear in the article exactly how the researchers dated the femur bone, but one possible way is through radiometric dating. To answer your second question, scientists have already sequenced Neanderthal DNA, and have established a finite copy of it. Another possible way they could have dated the femur bone is that they compared it to the Neanderthal DNA and found many similarities.
DeleteHow did scientists not hunk that it could have come from somewhere else.That is it fell in to the river and ultimately froze here.How Isis they determine it was a Neanderthal
ReplyDeleteScientists think of the most logical answer. Perhaps your scenario might of occurred, but the conclusion they came to is a more likely answer.
DeleteThe scientists determined that the human was descended from the Neanderthals because scientists have established a finite sequence of the Neanderthal DNA. After they sequenced the DNA of this human, they compared it to other humans around at the time. They found that it was very similar to Neanderthal DNA.