Week 4: TEETH!

In the 4th chapter of "Your Inner Fish," Shubin specifically talks about the evolutionary importance of teeth and how it evolves from the simple teeth of a lamprey to the highly-specialized teeth indicative of the mammalian condition. Being very interested in dentistry and wanting to expand upon what Shubin said,  or this week  I'm going to focus on the implications of mammalian teeth specializations by showing one of the figures from my vertebrate evolution textbook that depicts the teeth variations from ancestral mammals (on the left) and more derived mammals (right). As you can see, the more derived mammal has a "caninelike tooth" along with smaller teeth towards the front. This marks one of the first changes to modern-day mammal dental formulas. More importantly though, teeth specializations represent major changes in how organisms went about eating food. Canines promoted grasping of food, incisors were used for tearing/shearing, and molars specialized in grinding. Prior to teeth specializations, virtually all organisms implemented a simple method of tearing off food and swallowing it, NEVER chewing. With the advent of molars, mammals became the first organisms to be able to chew their food, allowing many previously-unoccupied niches to spring up (large rise in herbivores). In my opinion, mammals owe much of their ecologic success to these dental modifications. It allowed them to easily outcompete birds, snakes, lizards, and other terrestrial vertebrates by being able to adapt a whole variety of eating methods that minimized bodily harm, vulnerability to other predators, and maximize advantages over food/prey. I could keep going on with this for pages on end, but I just wanted to share a side story about Shubin's talk of the evolution of teeth because it's really amazing how important teeth are to the success of mammals.