Seven Questions for Herpetologist (and Taxonomist) Darrel Frost
by AMNH on
Herpetology Curator Darrel Frost thinks of himself as a lizard guy, but he’s perhaps best known for creating and maintaining Amphibian Species of the World, an online database and classification system that now lists about 7,000 amphibian species.
The catalog has become an important resource for biologists, conservationists, and policymakers worldwide, and shows how the work of scientific classification has real impact on efforts to protect threatened and endangered species. (For more on classification and collections, see our new series Shelf Life, with monthly original videos, featuring Dr. Frost in Episode 2: Turtles and Taxonomy.)
Dr. Frost sat down with us to talk about taxonomy, technology, and the evolution of scientific classification.
A way of organizing the world around us. Taxonomy gives a common language to scientists and provides a unifying influence for conservationists and policymakers to talk to one another. That’s what [Carl] Linnaeus did when he took these very long Latin descriptions that people used and made them short and easier to remember.
So Linnaeus’s binomial nomenclature is the shorthand of scientific classification?
Like Sceloporus, the fence lizard genus, has maybe 50 species in it. It would be really hard to remember if we called one species “The lizard on a fence that lives in Michoacán, and it’s kind of green, except when it’s not, like in July when they’re breeding and they get red on their sides.” Linnaeus created these memory tags that allowed people to handle a lot of information. That’s what taxonomy does.
What are some of the biggest changes in taxonomy you’ve seen over the course of your career?
The ease of DNA analysis and the capabilities of data handling have really changed the field. For my dissertation, I looked at 40 to 50 species of lizards to figure out their relationships. Students in herpetology are now looking at 600 species, and the timeline is much shorter. It’s much faster using a computer than going, “Well, do these look the same or not?”
The pace is phenomenal. In 1882, there were 933 named species of amphibians. In 1985, there were 3,984. Today, there are more than 7,000 named species.
Are there any downsides to this fast tempo?
The flip side of data processing power is the informatics problem: how do you handle so much data, and what good does it do you? At the end of the day, doubling the data won’t necessarily get you double the answers.
What did people do before all this fancy technology?
Linnaeus and Georges Cuvier—an exquisite comparative anatomist in late 18th, early 19th century Paris—they were really smart people. They were just trying to sort the world.
Cuvier made a distinction between function and form, really the beginning of a distinction between homology and analogy, as improved upon by the French naturalist, Etienne Geoffroy Saint-Hilaire. Homologous structures are those that developed from similar origins—like our hands would be homologous to a whale’s flippers—and analogous structures are those that perform similar functions, but evolved separately—like bird wings and bat wings.
What Darwin then did was basically come up with an economic theory to explain this transmission and how things change through time. But all that did was give meaning to words that people were already using. The structure was there.
As the way scientists classify things changes, are there any categories that are becoming outdated, or meaningless?
The word “reptile,” for example. That’s just a descriptive term that we use to collectively unite things that look similar. Doesn’t have anything to do with evolution. Reptiles and amphibians were stuck together in herpetology because they weren’t mammals or birds. Nowadays, no competent taxonomist uses the word Reptilia in a formal classification. Unless they include birds as well.
And even though reptiles and amphibians are still housed in the same collection, crocs are more closely related to birds, lizards are outside of that, and the whole “reptile” group is closer to us than they are to amphibians. So, it doesn’t make any sense in terms of evolutionary history. It’s just a historical artifact of a time when reptiles, amphibians, and fish were the pickled stuff that was kept in jars.
So they’re actually strange bedfellows.
In fact, I named an amphibian taxon that once. It was Xenosyneunitanura—from the Greek for “strange bedfellows”—because its nearest relatives are pretty dissimilar. It’s not pronounceable, which was kind of a problem. But I liked it in principle.