The Anatomical Similarities of Mice and Humans, and Why Mice Are Useful in Human Research.

The Anatomical Similarities of Mice and Humans, and why Mice are Useful in Human Research.

Megan Lau

Biology 205

Dr. Richard L. Stoffer

October 25, 2013

The animal group Rodentia is one of the largest groups of all mammalian species. In that group, are two of the most influential mammals in animal research for humans. Mice and rats are considered to be the prime role model of inherited human diseases, and 99% of their genes are the same as humans, which give researchers an insight into the development of different diseases and biological processes in humans.

Rodentia, with about 1,500 living rodent species, is home to the majority of mammals on earth. The Rodentia group includes mice, rats, guinea pigs, hamsters, muskrats, beavers, chipmunks, woodchucks, porcupines, prairie dogs, squirrels, chinchillas, and many others. Rodents are native to all the continents except Antartica. Rodents make up approximately 43% of all mammalian species. There is a broad range of characteristics throughout different families of Rodentia, but the one characteristic that sets rodents apart from any other animal Order is their teeth.

The name Rodentia comes from the Latin verb Rodere, which means to gnaw, this name is suitable for Rodents because they are constantly gnawing things with their specialized teeth! Rodents all have one pair of upper incisors in their mouth that are continually growing throughout their life span. These incisors have a very thick layer of enamel in the front, but not on the back, which gives them their shape as they are worn down. They also have diastema, which is a large gap in the rows of teeth behind their incisors. They have no canine teeth and usually only a few molars at the end of the jaw. They also have one pair of lower incisors that also grow continuously throughout their lifetime. With these specialized teeth, they have large complex jaw muscles, and modified skulls and jaws to accommodate these muscles. Rodents are mostly herbivorous,...