Yesterday afternoon, I attended a seminar on campus given by a man who, alongside his father, has been studying predatory garter snakes. Common prey items of these snakes include newts that contain a variably lethal toxin known as tetrodotoxin, or TTX. He enthusiastically discussed what he calls an “evolutionary arms race” between predator and prey. This man’s name is Dr. Edmund Brodie from the University of Virginia.
It turns out that certain snake populations, or locales, have become resistant to TTX. Through extensive explanations regarding modifications in genetic material, Brodie showed us that certain changes in amino acid sequences have allowed this development of TTX resistance to occur over evolutionary time.However, as I stated before, only a few populations of garter snakes have been able to trump the toxicity of the newts they eat.
Individual populations of garters in central Oregon and around the San Francisco Bay in California are the only few known do have genetically evolved resistance more quickly than the newts have been able to alter the chemistry of their toxin. But, in most areas, these newts have remained at least somewhat successful in deterring their slithery predators.
He and his father, among other professional colleagues, continue to study the relationships between these snakes and newts throughout the United States and Canada.
Maggie
Personally not a fan of snakes… but you have some really intriguing information here. I laughed when I read your “evolutionary arms race” portion of your blog, it’s a great way to explain what’s genetically going on within these two animal populations. I’m curious to know if any other species have co-evolved like this… Anyways, great first blog!
Anne
The article leaves me wondering more about this subject – for example, what implications might the TTX resistance have in these snakes? They obviously do get more prey, which is beneficial to them, but could it effect newt populations negatively, or alter the ecosystem in some way? I was also curious if TTX might be found in another animals aside from just newts.
This subject is interesting to me, and worth researching more. Dr. Edmund Brodie sounds very enthusiastic and knowledgeable on the subject, and I really liked the language used in this article to inspire interest.
Kathy
“deterring their slithery predators” is a great phrase!
I’d love to see some pictures, and read further through links. Annie asks good questions, too.