Write things. Estivate. Acclimate. Repeat.

The musings, brain droppings, and research interests of Nick D. Waters

The exterior morphology, the body plan, says "frog" but it is not itself, a "frog". Ascaphus, from the Pacific Northwest of North America, along with Leiopelma in New Zealand, are a sister clade to all other living frog species. After Antarctica froze over and Zealandia sank, the bulk of that lineage was simply gone. Two hundred million years of evolution, and we would still instantly recognize them, long before the dinosaurs. That is Mt. Improbable staring you in the face, like Mt. Everest. The major sweeps of evolution are shaped by dumb luck, but we can infer qualities of organisms that may suggest lineages that are most likely to overcome bad luck. More on that later.

Phylogeography

October 24, 2026.

This post is going to open a can of worms, or, better yet dump out a bucket of banana slugs, and they will crawl all over the place and be difficult to corral. Anyone who has collected dozens of banana slugs out of their garden knows what I'm talking about. It is an endless swarm, and you can just forget about trying to grow anything unless you collect the things every single day. Walking them down the road to another neighbor's yard just doesn't work. They seemingly come back overnight. The neighbor is doing the same thing to you when you aren't looking.

Phylogeography is the study of evolution over space and time. The discipline seeks to understand the diversity of organisms and how they came to be where we find them. It notably integrates molecular data which lends itself to quantitave analysis, complementing Hennigian cladistics and historical biogeography. As the discipline has matured explanatory models have emerged. Evolutionary biology is concerned with discovering the models, and applying them to species is the essence of the discipline. I find it endlessly fascinating, and there is a tsunami's worth of information and data available if you just go look.

I have unfinished business with these three types of critters because their story is untold and I have skin in the game because of good luck at being able to find them, possibly cursed, and spend way too much time ruminating over them: tailed frogs (Ascaphus), Pacific giant salamanders (Dicamptodon), banana slugs (Ariolimax), and the helminthoglyptid snails from the southwestern deserts of North America.

The snails are presently foremost on my mind so I will begin there to clear the cobwebs. I will be gathering up all the relevant papers and posting my thoughts. I will do the same with the other critters.

I have done a lot with Ascaphus and Dicamptodon, and those papers await my attention. Hopefully the other authors haven't just redone everything to get me out of the way, but it's a possibility, and frankly would not blame them. That work seeks to explain the last 15 million years, and the last 5 million in particular. Ariolimax I have yet to fully dig into, because I am in a holding pattern describing a species from the Klamath Mountains due to Barry Roth's passing and a lot of other's work having not been published, but appears to be back on the table.

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