Why do gorillas have canine teeth?

[jimmydasaint]

This is a puzzle to me. Why is it that gorillas,, who are herbivores, to the best of my meagre knowledge, have well-developed canine teeth? Are they as strong as those of carnivorous animals? If you had found a fossil of a gorilla with forward facing eye sockets and well-developed canine teeth, does that not show a carnivorous past?

 

Any views?

canine teeth

[SMF]

It takes a very long time for a trait to become vestigial and disappear. More often the trait is co-opted to be used for other related purposes. For example, we have canines that are still useful. In order to evaluate gorilla canine usefulness one would have to study all their habits to see how these teeth are useful for breaking up vegetable matter, killing prey, defense, as a tool, or for interactions with other gorillas. Maybe some scientists have already done this. Why don't you do a literature search and tell us. SM

[lemur]

I would think the canine teeth would have to be replaced by some mutation that immediately gave some advantage to individuals with that adaptation OR the canine teeth would have to cause some problem that prevented individuals with such teeth from reproducing. Otherwise the trait would simply continue to reproduce in subsequent generations regardless of its use or functionality. Species don't evolve to adapt, they adapt through evolution as a result of random mutations. If such random mutations don't occur, they just go extinct.

[AzurePhoenix]

The canine teeth are functional, they're used to crush tough plants, and are an important threat display, for intimidating rival males or potential predators.

[lemur]

The canine teeth are functional, they're used to crush tough plants, and are an important threat display, for intimidating rival males or potential predators.

That explains it. Rival males saw the fearsome canines of their tough-plant-nourished competitors and subjugated themselves to becoming non-reproductive support staff for the alpha-males.

[SMF]

Lemur:

 

That explains it. Rival males saw the fearsome canines of their tough-plant-nourished competitors and subjugated themselves to becoming non-reproductive support staff for the alpha-males.

 

I am unable to tell what you are saying here. SM

[jimmydasaint]

I am a bit pushed for tine, but I will say that I find the results quite mixed, as this article seems to indicate.

Among anthropoid primates, it is well known that the canine teeth of males are up to four times as long as those of females. The researchers compared the canine teeth of male and female primates.

“If the male’s canines are stronger than the female’s canines that would imply there is sexual selection for strength and that the tooth is actually used as a weapon,” Plavcan said. “Female’s canines are short, and shorter, stubbier objects are harder to break. So, if the long, thin male canines are as strong or stronger than those of the female, that would also suggest they are capable of being used for fighting.”

The results were mixed in an interesting way.

“We found that the primate canines are generally as strong as or stronger than carnivore canines," Plavcan said. “But they are not associated with any sort of estimate of sexual selection.”

Generally the canines of males and females were equally strong. Given that primates have such strong teeth in general, the researchers suggested a couple of possible explanations. It could be that all primate males have strong teeth because of a significant risk to reproductive success for any male who breaks a canine tooth. Or it could be that the strong teeth are due to basic inherited design

Science Daily

[lemur]

I am unable to tell what you are saying here. SM

It's just a social-behavioral scenario for how canine teeth could result in some gorillas reproducing and others not. That's how evolution works, in theory anyway (it's natural eugenics).

[Jo5er]

Seems you are ALL wrong. The reason they have teeth is NOT for protection or to eat tough shoots ect. They are omnivores. They eat meat as well. Don't believe me? Google it!!

[Greg H.]

Seems you are ALL wrong. The reason they have teeth is NOT for protection or to eat tough shoots ect. They are omnivores. They eat meat as well. Don't believe me? Google it!!

Actually, a study done in 20101 indicates that we're not quite sure if gorillas eat meat or not. The study found three possible reasons for the presense of vertebrate DNA in the fecal matter of bonobos and gorillas. First, obviously, they were eating other small animals. Second, it could be contamination from the environment. Third, it is possible that some populations eat meat and others do not (similar to the differences in diet among populations of humans).

 

It would be more reasonable to say that it is possible that some gorillas eat meat, but this has nothing really to do with the presence or absence of canines in the primate population. The answer is probably very complex, and stems from a variety of factors, such as dominance/mating displays (with larger canines being favored thus leading to more offspring), defense (larger canines leading to more adequate defense bites, leading to more offspring), or past environmental factors that led to those with larger canines surviving better (again, more offspring). The answers to these questions are rarely very simple, pithy statements like "They eat meat!" We eat meat too, and our canine teeth are pretty diminutive compared to a chimp or a gorilla.

 

It might also interest you to know that there are several herbivores that have canine teeth - such as the horse.

 

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See Hofreiter, M, et. al. Vertebrate DNA in Fecal Samples from Bonobos and Gorillas: Evidence for Meat Consumption or Artefact?