Fangs You Very Much, Evolution
Where did the snake get its fangs? It sounds like the lead-in to a Rudyard Kipling Just So stories, but it’s a legitimate evolutionary biology question about one of nature’s deadliest weapons, one that goes back 20 million years ago to the oldest snakes in the fossil record. But even those ancient snakes had fangs similar to the poisonous snakes of today, with a hollow tube running through the tooth to inject venom into some poor prey like a hypodermic needle. How snakes (and other venomous reptiles) evolved such an elegantly dangerous mechanism was a mystery, until a new study published this week by University of Chicago’s Jonathan Mitchell and colleagues.
To study the evolution of snake fangs, Mitchell and his team were forced to go to a non-snake reptile – the mysterious Uatchitodon, a roughly 200 million year old reptile known only by its teeth. But in this case, the teeth were what the scientists cared about, and they compared the dental fossils from Uatchitodons found in Virginia, North Carolina, and Arizona. Interestingly, the teeth of older specimens appeared to show a kind of proto-fang, with a “canal” running down the outside of the tooth for the delivery of venom. This style of venom delivery is more similar to the modern-day Gila monster, the authors wrote, which “chews” its venom into its victims (shudder).
Later Uatchitodon teeth display a new form more similar to modern snakes, with the once-external groove now hidden inside the tooth. “This fossil really suggests that you can’t get hollow fangs any other way,” says co-author Wolfgang Wüstertold Nature News. Indeed, modern snakes even demonstrate a fast-forward highlight reel of this evolution, with grooved “replacement fangs” that give way to the mature, tubular model. It’s also a demonstration of the kind of transitional, evolutionary process that intelligent design supporters absolutely hate, demonstrating that the highly successful fang mechanism didn’t just appear out of nowhere, but through a series of intermediate steps that were also functional in their own right.
Another Bridge to China
The effort to help Wuhan University revise their medical school curriculum, described here yesterday, is not the only current collaboration between the University of Chicago Medical Center and Chinese hospitals. Last month, a delegation from Comer Children’s Hospital and the Department of Pediatrics visited Shanghai, where they signed an agreement establishing an educational, clinical, and research collaboration with Shanghai Children’s Medical Center (SCMC).
The relationship between the two pediatric hospitals sprouted from a training program started by Donald Liu, professor of surgery at Comer, who has taught minimally invasive techniques to surgical fellows from the Shanghai hospital for the last 10 years. For a disease called gastroschisis, where an infant is born with their bowels on the outside of their body, Liu’s instruction helped SCMC improve survival rates from 30 percent to 95 percent in 10 years. The success of that informal program and a successful visit from SCMC leadership to Chicago last year inspired the expanded collaboration, which will begin next year.
To read more about the delegation’s experiences in China and the partnership plan, see the article and video of the signing ceremony on the Comer website. You can also find several more examples of University of Chicago projects in China at the University of Chicago Center in Beijing site.
The massive Society for Neuroscience meeting, an annual pilgrimage for me in my former life as a graduate student, was held this week in San Diego. This year’s celebrity speaker (I saw the Dalai Lama and Frank Gehry in previous years) was Glenn Close, the actress who famously had her genome sequenced earlier this year. New Scientist wrote up her talk, and provided a whole bunch of other fascinating dispatches from the meeting, on topics such as hormone spray charity, virtual reality stroke rehab, and the female orgasm. Another favorite study to leak out from the meeting: scientists find that jet lag may cause learning and memory problems.