Research on canine strength of primates

The work of measuring and examining the teeth of living primates can open a window to understand the earliest behavior of humanity, based on their fossil remains.

The research, funded by the National Science Foundation and led by anthropologist Michael Plavcan of the University of Arkansas, brings us closer to understanding the relationship between canines, human size and life. primates.

In an article published in the American Journal of Physical Anthropology, Plavcan and colleagues Christopher B. Ruff, John Hopkins School of Medicine, presented a preliminary examination of the function of canine shapes for primates. . This is a comparative analysis published for the first time about primates' power of primates.

Understanding more about canine functions can lead to new models that help understand human evolution. Plavcan has studied primates and skulls for 24 years and spent four years collecting dental data for this analysis.

The researchers compared the size, shape and strength of canine teeth from 144 primates with the same parameters of 45 carnivorous species. They examined the relationship between the size of primates' canine teeth and their body size and strength. This comparison can help answer the calculations of the function of male primates in the process of competing with females. Can fangs be used as weapons or for display only?

'The reason we want to use carnivorous teeth is because we know carnivores use fangs to kill prey. If the primates 'canines are so weak that they cannot be used as weapons, it is obvious they are just for scenes.'

(Photo: H.Sleinberg)

For apes, male canines have a reputation of 4 times longer than females. The researchers compared the canines of male and female primates.

Plavcan said: 'If the male's canines are stronger than the female's, that means there is sex selection for strength and the teeth are actually used as a weapon. The female's fangs are shorter, but shorter and larger objects are harder to break. So, if the male's long, thin canines are also stronger or stronger than that of the female, it also suggests they can be used to fight. '

The results are not clear but quite interesting.

' We found that primates' canine teeth are usually as strong as or more than those of carnivores. But they are not related to judgments about sex selection . '

In general, male and female canine teeth are equally strong. Knowing that primates generally have strong teeth, the researchers offer two possible explanations. It is possible that all male primates have strong teeth because their reproductive success is threatened when their canines are broken. Or maybe the healthy teeth are due to genetic structure.

Hominids, the primates that give birth to humans today, retain their gender-based sexual dimorphism, meaning males often have a greater body weight than females. At the same time, the size difference between male and female fangs is lost.

Plavcan explains ' This goes back to the oldest anthropomorphic gibbon. In fact, one of the predictive characteristics of hominid evolution is the reduction of canine-sized dimorphism while retaining the body weight. '

For example, gorillas have large, short and strong teeth that correspond to massive bodies. To get the same proportions as other primates, the male gorilla's canines will have to be 25cm long, and the teeth in the jaw will become too wide for its jaws.

This suggests that there may be a limit to the canine teeth of primates simply because of space constraints to fit these teeth into the jaw.

The difference in body size between male and female hominids has long been a subject of study because it is a clear and important feature. But there are also limitations of using body size to understand sex selection. The size change can affect many other aspects of life, including metabolism, food consumption habits and the risk of predators. However, canine teeth are a much simpler system.

'With canines, we can create an experiment that allows us to control all of these variables and focus on one thing. The same phenomenon occurs with fangs, we can deduce body weight and behavioral model for fossil data. '