Sunday, February 7, 2016

Error in DNA Study of First Ancient African Genome

In October of last year, the first ancient human genome ever found in Africa was reconstructed. Dr. Manica and his colleagues' research was based off of the 4,500 year old Mota man. The skeleton was given his name from the cave he was found in Africa. DNA dating back to ancient times from this part of the world is hard to find because of its hot and humid climate. The limited amount of data and knowledge from ancient Africa allowed the geneticist's mistake to go unnoticed, that is until two other geneticist reanalyzed the results.
Dr. David Reich and Dr. Pontus Skoglund asked for the original data to help with their studies of ancient human populations. As the two Harvard Medical School geneticists reviewed Dr. Manica's work they came to the realization that it was incorrect. It became clear that the genome shared some DNA with Eurasians and was not as closely related to people in other parts of Africa as originally thought. The mistake made by Manica and his colleagues was relatively minor but had a huge impact on the overall results. Two programs were used in the research, one mapped the DNA while the other compared it to other genomes. From the one program to the other the format had to be changed, but the researchers neglected to do this. Unfortunately, bypassing this step caused for inaccurate data. 

 From Dr. Manica's results it was believed that the back flow that happened approximately 3,000 years ago when people migrated from the Near East back to East Africa spread all across the continent. This flow of humans supposedly explained why many Africans had DNA identical to Eurasians. When the mistake in the genome was found the geneticists found that only East Africans had similar Eurasian DNA. The original story of the back flow was true, but not completely accurate.

Although, a mistake was made it is still incredible that geneticist are able to collect data from thousands of years ago. Hopefully, this issue will help other researchers in the future to avoid making similar mistakes. Now that Reich and Skoglund have come up with the correct data we will be able to learn more about people from this time and location.

No comments:

Post a Comment