‘Teeth took 400 mn yrs to evolve’

A University of Arkansas anthropologist has actually written a book on why mammals developed teeth in the first place.

Last Updated: Sep 20, 2010, 10:19 AM IST

Washington: Examining the 400 million years of evolution that took us to take a bite of that sinful apple, a University of Arkansas anthropologist has actually written a book on why mammals developed teeth in the first place.

Peter Ungar`s book, titled `Mammal Teeth: Origin, Evolution, and Diversity`, examines the tension between the feeder and food, which also evolved ways to minimize the chances of being consumed.

Developing teeth meant being able to fracture food into easily digestible pieces and allowed mammals to survive in cold climates and become active at night.

"Teeth give you more options in terms of diet," said Ungar.

Teeth can slice and dice, and also crack and crunch, allowing mammals to expand into the diversity of diets they have today.

The second section of the book discusses how teeth have evolved through the ages to today.

The first tooth-like structures date back almost half a billion years. Ancient fish developed mineralized formations in their mouths, perhaps evolved from skin denticles like those seen in sharks today.

Ungar looks at the evolution of jaws, teeth, chewing muscles and the bony palate that separates chewing and breathing.

"When you chew, it`s like a symphony," said Ungar.

The mouth produces the right amount of saliva. The teeth align to chew, and the tongue moves the food around. The jaw muscles work and the ligaments allow just the right amount of pressure to crush or slice the food without cracking enamel.

ANI