Bipedalism In Anthropology

The world of anthropology is ever changing and each new discovery can discredit multiple other discoveries. Laetoli, Tanzania has been one site that has discovered and rediscovered multiple species of hominins, but the greatest discovery there was an ancient footprint trail left by our hominin ancestors. There have been other footprint trails discovered in other parts of the world, but none as old as the Laetoli trail. The Laetoli footprints are important because it lets us look into the species that created them, what kind of body mechanics were required to create them, why bipedalism was so important, and it gives ideas of preservation for not only their site, but for other sites in the future.

Laetoli is twenty-five miles southwest of

Mammals need to keep a certain range of internal body temp and it is important that the brain doesn’t overheat. A small spike in brain temp will cause irreversible damage, so keeping the brain cool is a must. The only way quadrupeds can cool their brains down is by sitting their entire body in the shade and avoiding the sun. When they are on all fours, the sun is pounding directly on their backs and the large surface area of the back will increase body temp faster than a smaller surface area. When an animal walks bipedally, they can reduce the surface area where the sun is hitting them. They receive less rays from the sun and it doesn’t affect their body temp as much as the larger surface area. Another advantage is bringing the upper body, specifically the brain, a few feet higher off the ground and into a cool breeze and slightly cooler temps. This also aides in sweating and might be part of the reason that humans do not have the thick body hair that our ape cousins have

Owen Lovejoy wrote a paper about his theory in 1981. Another theory of bipedalism stems from the idea of pair bonding. When mammals shift from quadrapedalism to bipedalism, the birth canal shrunk by a great measure. To be able to still produce offspring, the bipedal mammal would have to give birth to a smaller and more dependent baby. The dependence of the newborn meant that the mother would have to spend constant attention with the baby and would not be able to hunt or gather food for her or the offspring. The male, most likely the baby’s father, would be responsible for gathering food for his nuclear family. While walking upright, the male would be able to travel farther for food using less energy and have hands available to bring enough food home for everyone. The idea of pair bonding would increase the odds of the offspring’s survival and effectively carry on the lineage of the species. Through the idea of early pair bonding, the theory of the evolution of secondary sex traits comes apparent. Males with more facial hair and females with larger breasts would become more appealing for mating with