Sabrina Tavernise talks to Carl Zimmer about DNA from Bronze Age skeletons providing new insight into modern medical issues.

Feb. 4, 2024 

Carl Zimmer covers life sciences for the New York Times and in this episode of The Daily, he discusses a story he recently wrote regarding a major discovery in our understanding of ancient people with host Sabrina Tavernise.

Zimmer gives some context regarding the article he wrote, noting that there are two major questions scientists have wondered about for a long time: why do we get sick and where do we come from? He goes on to say that scientists have tried to answer the question of why we get sick by looking back at the lifestyles of our ancestors, specifically asking what challenges they faced, what their health was like, and what genes they carried. 

According to Zimmer, researchers have recently made some very big discoveries regarding both human history and diseases simultaneously, in the form of genes that we still carry today. He notes that in the past, researchers were relegated to fossils for studying ancient life, which was difficult due to the limited supply of relevant fossils, but now researchers can access DNA through fossil samples. 

"This actually gives you a glimpse into the molecular life of these ancient people or ancient animals." Zimmer said. "And it’s amazing enough when scientists can get just a single gene out of a fossil that’s thousands and thousands of years old, but actually, the science has come so far in recent years that it’s pretty common for scientists to get a whole genome of an extinct species."

Zimmer expanded on the importance of this by explaining how we are now able to determine a wide range of information from being able to extract genes from fossils and the one I found to be the most interesting was the fact that we can track the migratory exploration of our ancestors by looking for certain genes in fossils and matching them up to others from different areas to develop a recognizable pattern of movement. 

The importance of this to modern medicine comes in the form of being able to track certain genes that give people a predisposition to diseases such as heart disease, cancer, or schizophrenia back toward ancient populations to narrow down when these mutations arose to give us a better understanding of these diseases.

Even more important is the Yamnaya, a farming and livestock herding population that lived between 5,000 and 6,000 years ago. Because the Yamnaya lived in constant proximity with animals, they began to mutate and pass on genes that greatly increased the activeness of their immune systems to fight off any diseases that they would get from the animals.

These mutated genes that so greatly benefitted the Yamnaya are the same ones that today can put people at risk for certain diseases, namely multiple sclerosis. MS is a disease that makes your immune cells recognize nerves in the body as diseases and attack your own nervous system. 

After finding Carl Zimmer's aforementioned article, I found that Zimmer wrote the article in response to a study on MS and research into the Yamnaya tribe.

Finally, I could not really find any challenges that Zimmer might have faced based on the podcast or his article aside from the fact that reading through studies can be a bore. He condensed the information well and provided interesting insight into a topic that otherwise might have put me to sleep.