Science of gnathostome jaws explained.
A Dalhousie biology professor explained the science behind building a gnathostome during a talk to Mount Allison’s biology department this past Friday.
Andrew Gillis’s seminar centred on how the mandibular jaw is developed in cartilaginous fishes. By looking at cartilaginous fishes, such a sharks, rays, and skates, Gillis hopes to gain better understanding of the changes that occurred during evolution. Cartilaginous fishes uniquely share primitive aspects that may other species have lost over time; this makes them prime candidates for observation on how the lower jaw is formed.
In the past, scientists had observed that both the lower jaw and paired fins shared a similarity to the gills on cartilaginous fishes. While the idea was intriguing, there was no way to say whether this was anything more than a coincidence.
This is where Gillis comes in. Using today’s modern research methods, he is able to map the development of the embryos. It is possible to watch the development of the jaw using dyed cells. As it turns out, the development of the jaw does stem from the gills in cartilaginous fish.
Gillis now wants to look closer to the relationship that the gills and paired fins share. So far he has received promising results but it is still too soon to draw any conclusions.
Gillis began his career in biology aspiring to become a medical doctor. It was only after taking a course from professor Vett Lloyd (who now teaches at Mt. A) that he decided to pursue a career in research, quipping that he became an underpaid doctor instead of a highly paid medical doctor.
Upon completion of his undergraduate degree, he continued on at the University of Bristol where he completed a master’s in archeology. For his doctorate, he retreated back to biology, and studied at the University of Chicago, with a following post-doctorate fellowship at Cambridge.
