In the early 1990s, the idea of ancient DNA seemed like it would forever remain the stuff of science fiction, despite the best efforts of scientists. Michael Crichton gets credit for imagining the possibility for his 1990 novel
Jurassic Park, turned in to a movie three years later by Steven Spielberg. In Crichton's telling, mosquitoes feast on dinosaur blood, get trapped in amber, and millions years later offer up dinosaur DNA to science and the theme park industry.
Just a year after the movie came out, a Utah geneticist published a
paper in the journal
Science, describing a gene he extracted directly from an 80-millon-year-old fossil that likely belonged to a dinosaur.
As a newbie science writer at the time, I found this discovery mind-boggling. While I doubted anyone would be resurrecting dinosaurs, the ability to see the DNA of ancient organisms like dinosaurs would give paleontology an extraordinary precision. But it turned out to be too good to be true.
In a biological
self-own, the DNA proved to come from
a human who handled the fossil. That a scientist could believe a snippet of human DNA came from a long-lost reptile tells you a lot about our deep ignorance of genetics at the time. Soon, other biologists were poo-poohing the idea that DNA could survive for millions of years. The whole conceit of ancient DNA seemed pointless.
But the pendulum swung back. Thanks to the sequencing of many genomes, including our own, scientists can spot contamination more accurately. They also have lots of new procedures to avoid contamination in the first place. They have learned how to squeeze DNA out of some very unpromising fossils. They can even get ancient DNA out of dirt.
Jurassic DNA may not be a thing, but Pleistocene DNA is. It can last for hundreds of thousands of years, and can tell us a lot about recent evolutionary history--including our own. Last month, Svante Paabo won the Nobel Prize for resurrecting ancient DNA from Neanderthals and other early humans.
In the wake of Paabo's prize, I published a pair of stories that give a sense of just how much detail we can now see. In Russia, Paabo and some colleagues have found a
Neanderthal family, with a father and daughter linked by their genes. And in London plague cemeteries, other researchers have found evidence of
natural selection at work in the Black Death.
In other news,
the politics of Covid's origins continue to simmer--and will likely flare up if the GOP takes the House. Meanwhile, ongoing experiments with SARS-CoV-2 illustrate
the need for clearer, stronger guidelines to ensure lab safety.
Finally, on the social media front, I'm puzzling over what to do as a journalist amidst the ongoing chaos on Twitter. I'm still @carlzimmer for now, but I'm also checking out Mastodon as @Carl_Zimmer@mastodon.social.
That's all for now. Stay safe!
You can find information and ordering links for my fourteen books here. You can also follow me on Twitter, Facebook, Goodreads, and LinkedIn. If someone forwarded this email to you, you can subscribe to it here.
Best wishes, Carl
