Through the cold, dense undergrowth in Northern America, a swollen tiger salamander is on the search for the ideal place to lay her eggs. It could be a pond, or a melted puddle of snow, she doesn’t mind. Just as long as she finds it soon. Finally, she comes across a small pond, submerges herself and releases a thousand tiny eggs into the icy water. Now that her job is done, she leaves the pond in search for food and doesn’t look back. Her offspring will have to fend for themselves.
Not long after, a crack appears on the surface of one of the eggs. Breaking free from its shelter, a tiger salamander larvae emerges into its new temporary home. As the larvae will soon learn, it’s journey to adulthood will not be an easy one, as it could be lunch for just about any animal living in this pond. Around every bend is the possibility of coming face to face with a predator, whether it be an aquatic insect, a fish, a newt, or a sharp eyed bird looking down on the pond from a tree branch. If it wants to survive its time in the water, it’s going to have to grow big, and it’s going to have to do it fast.
As it turns out, there is a way a tiger salamander can get ahead in this world. Instead of just being the prey, it can become a predator itself. When times are tough and competition is high, a tiger salamander larvae can undergo a drastic change, developing a broader head, a larger mouth, and a set of incredibly sharp teeth.
Our larvae friend has successfully morphed into a cannibal.
This morphing process gives the larvae a survival advantage above the rest, as it now has the ability to dine on its own kind. A much needed nutrient burst allows the larvae to grow much faster into its adult form, so it can get the hell out of that pond before it becomes someones dinner. For those that are unable to morph into a cannibal, the future looks a lot more grim.
Although this may seem alarming, several animal species are known to enjoy munching on their own kind every now and then. In a similar situation to the salamander, cane toad tadpoles will eat unhatched eggs to grow big and strong, and also cut down future competition. An even more dramatic scene unfolds inside the womb of a pregnant sand tiger shark, where the first embryonic shark to bust out of its egg capsule will devour its remaining siblings. This feasting allows the shark to grow large enough to take on predators once it is born and left to fend for itself in the big, wide ocean. Hippos, who were once thought to be herbivores, have also been caught eating the bodies of already deceased hippos in times of droughts.
The animal kingdom is also full of parents turning on children, and hungry females turning on their mates. Chameleons have been known to eat their young, but the Mexican lance-headed rattlesnake takes the cake by eating up to 70% of their offspring, gaining vital nutrients needed to mate again. Preying mantises and certain spiders are known to turn up the kink and chow down on their partners during copulation, while male fish from several species have also been caught munching on the eggs they were meant to be guarding.
However, cannibalism takes on an even more sinister tone when we look at our close relatives, the chimpanzee. Jane Goodall reported witnessing infanticide and cannibalism from both male and female chimpanzees, with further observations suggesting that this behaviour is relatively common. For these animals, cannibalism doesn’t just provide a good meal, but it also reduces competition, population numbers and potential threats. In a recent case, a group of young male chimpanzees in Senegal were caught killing a former leader, and then eating parts of the body throughout the day. Jill Pruetz, a professor of anthropology who witnessed the attack, believed that this behaviour was a result of fear, where the males were so terrified their fearsome leader would return from the dead that they made sure to destroy the body completely.
So how about us humans?
Do our cannibalistic tendencies fit more in with the hippos, who will eat their deceased friends in times of hardship? Or are we more aligned with our cousins, the chimpanzee, and more malicious with our reasoning?
Bring up cannibalism today and people will likely shudder at the thought of it. Their mind will head towards Silence of the Lambs and Jeffrey Dahmer, twisted pathological monsters that deviate from normal human culture. Maybe they can excuse it in situations where it is a survival necessity, trying to put themselves in the mindset of the Uruguayan rugby team that were forced to eat their dead teammates after a plane crash in 1972. However, the vast majority of people would not want to admit that cannibalism might be deeply entrenched in our human history.
But unfortunately for us, it is. And it may have even helped us evolve as a species.
First, let’s head back a million years ago, to a time when our prehistoric human ancestors Homo antecessor walked the earth. As it turns out, our distant relatives were rather fond of cannibalism, with human meat actually being part of an everyday meal. The 800,000 year old bones of butchered humans were found in a cave called Gran Dolina in Spain, and researchers believe that the meat wasn’t only eaten for nutritional value, but cannibalism was also a way of killing off local competition. And if this discovery wasn’t grim enough, the majority of the bones found belonged to children and teenagers, who were likely easy prey. Keep that in mind if you ever think your parents punishment is harsh. Evidence from Croatia, France and Spain also suggest that the Neanderthals were in on the action, as well as early Homo sapiens in Ethiopia.
Throughout human history cannibalism has been motivated by a variety of different factors, with it being present in spiritual and bereavement rituals, used as social control, and also called upon in times of starvation and warfare. Whether it gave early humans a survival advantage or helped groups bond or stay under control, it is believed to have had a prominent effect on ancient human society. Even though Western society frowns at the thought of it today, the practice is still alive and well in certain areas of the world. In Papua New Guinea, the Fore tribe will eat the remains of the dead during funerals, as a sign of respect. Certain tribes in India are also known to consume human flesh in the hopes of gaining immortality and supernatural powers.
So there you have it, probably more information than you’d like to know, served up to you on a plate. It’s lunch time now. I might opt for something vegetarian.