Molar roots are leftovers from 'Homo erectus'
The roots of our molars are leftovers from an extinct species of hominid, Homo erectus, it has been revealed.
Christopher Dean and Tim Cole at University College London, who studied the microscopic structure of adult molars to rebuild the pace of their development, found that the roots of chimpanzee molars go through a growth spurt as the teeth erupt through the gum, most likely to provide more stability for biting and chewing.
The study suggested that the same thing happened in early hominins, but not in modern humans as by the time our molars arrive, their roots have been fully developed for at least a year.
The researchers also found that Homo erectus gained its molars at exactly the same age as our molar roots have their growth spurts, according to the New Scientist.
According to Dean, in humans, root growth spurts are just a hangover from an early stage of evolution and we retain molar roots like Homo erectus because the growth spurts use little energy for natural selection to grew them out.