Yesterday, on the way back from a ride to Baker Wetlands I saw what I think was the biggest snake I have ever seen in the wild. It was probably just under 5 feet long, and over 2 inches in diameter. My best guess is that it was a North American Racer. I saw some rattlesnakes back when I lived in California, but I can't remember how big they were. I was so young.
I start Introduction to Linguistics at KU on June 6th. If that class goes well I might try to get a linguistics degree. Lord knows what I'll do if it doesn't.
This blog has now existed for over one year. Pretty incredible, I guess. Maybe not.
This post isn't a normal story about bike riding or some other adventure. I wrote a draft of that but just didn't like it very much. This isn't much better, I'm just talking about lizards.
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| O mio bambino caro! |
2 days ago I was looking at the Wikipedia page for Santo Stefano island, a tiny island in Italy that had a prison from 1797 to 1965, and basically nothing else. From there I got to the Santo Stefano lizard, a now extinct subspecies of Italian wall lizard that lived on the island.
What this led me to learn is that the Italian wall lizard adapts quite rapidly, and there are at least 50 subspecies. In 1971, an incredible experiment begun where some Italian wall lizards from one Croatian island (Pod Kopište) were moved to another (Pod Mrčaru). Scientists checked up on them over the decades to see how they changed.
The results were pretty cool, in just 36 years the lizards had diverged from each other significantly. Mostly due to how Pod Mrčaru didn't have as much meat to eat, the lizards had to be vegetarian. They got bigger and had higher bite forces. They also developed cecal valves, which are found in less than 1% of squamates. Cecal valves "slow down food passage and provide for fermenting chambers, allowing commensal microorganisms to convert cellulose to volatile fatty acids". (1)
One other place the Italian wall lizard have recently been introduced is here in Kansas. They are present in Topeka, Hays, and Lawrence. Kansas was a boon for these little guys, as their niche was completely unoccupied. Being a species adapted for rocky areas, they did great in urban environments. (Just like pigeons or "rock doves" as they are also called) The lizards got to Topeka first, possibly an introduction from Quivira Specialties, a store. How they got to Lawrence is unknown, but they have been here since at least 1999 in north Lawrence, and 2001 around KU.
So if the Italian wall lizard can change drastically from Pod Kopište to Pod Mrčaru in just a few decades, will that happen here too? Well, I'm not sure, but one big difference between Italy and Kansas is the winters.
The lizards already brumate through the winter, which they don't do in Italy. Another way lizards adapt to the cold is by having eggs that develop faster, or waiting until the embryos are further along in development before laying eggs. Many cold adapted lizards are viviparous and just do away with eggs altogether. That won't happen to our Italian wall lizards, seeing as the similar & native Six Lined Racerunner lays eggs like a normal lizard. There can also be some small under-the-hood changes to improve oxygen economy.
I don't think that Kansas will change the Italian Wall lizard all that much, to be honest. Even though this animal has the potential to evolve incredibly quickly to a new environment, it needs to have a reason. I don't think it will have much of a reason. Kansas and Italy are quite similar as far as the lizard is concerned.
As already mentioned, Kansas does have harsher winters than Italy, but that's probably the biggest difference between the two. Summers are similar in both places. Types of food available is probably quite similar, and so are habitats. There could be something I'm missing.
And I'm not saying that there will never be a Kansas subspecies of Italian wall lizard, there probably will be, but I don't think it will happen all that fast. I'd love to be proven wrong though, so it might be worth it for someone to round up some lizards in 13 years and see if they're different from those in Tuscany. They could also see if there’s any difference between lizards north and south of the river.
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| Home invader |
Sources:
(1) Rapid large-scale evolutionary divergence in morphology and performance associated with exploitation of a different dietary resource: Irschick et al.
(2) https://webapps.fhsu.edu/ksherp/account.aspx?o=32&t=46
(3) Plasticity and local adaptation explain lizard cold tolerance: Card et al https://onlinelibrary.wiley.com/doi/full/10.1111/mec.14575
(4) https://bioone.org/journals/northeastern-naturalist/volume-12/issue-3/1092-6194(2005)012%5b0349%3aSADAPO%5d2.0.CO%3b2/Seasonal-and-Diel-Activity-Patterns-of-Italian-Wall-Lizards-Podarcis/10.1656/1092-6194(2005)012%5B0349:SADAPO%5D2.0.CO;2.short
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