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SVP Romer Prize Interview: Aaron LeBlanc

Following the annual meeting, we're highlighting the student and early career award winners from the society. Today we talk with Aaron LeBlanc (University of Alberta; website and Twitter feed), winner of the 2017 Alfred Sherwood Romer Prize, recognizing an outstanding scientific contribution in vertebrate paleontology by a predoctoral student. Aaron received the award for his presentation, "Heterochrony and the Origin of the Mammalian Tooth Attachment System."

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What is your academic background up to this point? How did you get interested in paleontology?

I grew up in Edmonton, Alberta, Canada, so I had the Royal Tyrell Museum and the Alberta badlands to sneak off to in the summer. I don’t remember when or even why I got into paleontology, but I know it happened before Jurassic Park came out (I was 7 when it hit theatres). I must have decided at some point when I was really young that I was going to be a paleontologist and I haven’t wavered since.

I stuck to the plan and did my B.Sc. specializing in paleontology at the University of Alberta in Edmonton, an M.Sc. with Professor Michael Caldwell on mosasaurs at the U of A, and then a Ph.D. with Professor Robert Reisz on amniote dental histology at the University of Toronto Mississauga campus in Ontario. Now I’m back at the U of A studying all kinds of teeth as a Killam Postdoctoral Fellow.

Briefly, what was the main take-home point from your Romer presentation?

All mammals have a special tissue called a periodontal ligament that suspends their teeth within each tooth socket. The ligament maintains the proper positioning of the teeth as the animal grows (it’s this ligament that allows your teeth to move when the dentist makes you wear braces). The ligament also provides a flexible cushioning effect when mammals chew. That’s very different from the teeth of other amniotes, which are usually fused to the jaws by bone. I tracked the evolution of this ligament system in mammals by making histological sections and examining the tooth attachment tissues in a wide range of synapsids (the larger group to which mammals belong, which includes animals like the sail-backed carnivore Dimetrodon).

What I found was that the ligament is not a new tissue exclusive to mammals, but an ancient one that typically mineralizes and fuses teeth to the jaws in our more distant synapsid relatives. I concluded that the mammalian tooth attachment system is therefore a result of simply retaining the periodontal ligament in a non-mineralized state. I argued that the evolution of the mammalian tooth attachment system was an excellent example of heterochrony: a change in the timing or rate of a developmental process.

During your academic career to this point, you've worked on the teeth and jaws of everything from dinosaurs to early reptiles to mammals. Is there a particular common thread (beyond teeth and tooth attachment) in these projects?

I like to pitch myself as a specialist on an organ rather than on any particular organism. I’m interested in studying how teeth have evolved to suit their various functions through evolutionary time. That also means that I get to learn a lot about all kinds of different groups of amniotes, which I always find exciting. I try to take what we know from studies of extant mammals, lizards, and crocodilians, and apply that knowledge to unique and complex teeth in the fossil record. The common thread is always tooth development: how have teeth “bent” the rules of dental development to create new kinds of dentitions in ancient times? The results are often unexpected, and I think there is still a lot of room to do some fascinating research in dental histology.

What advice would you give to other SVP presenters who want to give a quality platform talk?

I think it’s important to treat an oral presentation like a narrative and not a research paper. You want the audience to follow along through your research “story” from the background, to the research question, to the results, and then to the conclusions. You also don’t want to lose them along the way. The minute someone gets left behind in your talk, they stop paying attention.

I find that the best thing to do is to give a visual-heavy talk that gives your audience an effective visual association for each of your major points. I always remember the figures and illustrations more than any text on a powerpoint slide, so I try to emphasize that in my talks. It also doesn’t hurt to get a little animated during your presentation and keep changing the verbal pace of your presentation. It’s a dark room and people doze off if you don’t keep up some energy and have them wondering what’s coming next.

Thank you, Aaron, and congratulations!
Posted: 9/20/2017 6:02:56 PM by andyfarkeadmin | with 0 comments
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