Homo Habilis: The Handy Man?

Homo habilis, first discovered in 1960 by the Leakey team in Olduvai Gorge, is proposed to be one of the earliest human ancestors. Estimated to have existed between 2.4 and 1.5 million years ago, habilis lived in Africa. Specimens have been uncovered in multiple present-day African countries including Tanzania, Ethiopia, Kenya, and South Africa. Louis Leakey, John Napier, and Phillip Tobias subjected their specimen to intense study, finally announcing in January 1964 that they had discovered a new species of Homo. The Latin name “habilis” was originally proposed by Raymond Dart. It translates to “handy man,” an obvious reference to the hominid’s presumed tool-making habits, which we will later examine.
Other similar bipedal species, such as Australopithecus boisei, are believed to have co-existed with Homo habilis, though habilis ended up thriving and making way for a completely new species while boisei simply disappeared from the fossil record. This could likely be a result of the tool innovation and less specialized diet of the species. It is also possible that Homo habilis and Homo erectus co-existed in Africa for as long as 500,000 years. The face of Homo habilis is still primitive and projected out, though there is less projection when compared with earlier species. Its jaw is reduced in size, pulled farther under the brain, and includes smaller molars. The teeth are arranged in a more rounded arc, similar to the arrangement of modern human teeth, though the incisors are still relatively large. The skull has a distinctly round shape, vertical sides, and a small forehead above the brows. Two evolutionary trends are apparent in hominids: increasing brain size and a corresponding reduction in face size. These trends are observable in Homo habilis, who had an average brain size of 650 cc (significantly larger than chimps and earlier hominids) as well as a smaller face. The brain shape in habilis was more similar to a human than a chimp, and Broca’s area, the part of the brain responsible for language, is visible in at least one habilis brain cast. The brain case was fuller and more rounded as a result of the expansion of the brain.
At 1.3 meters tall and 37 kilograms, the average male habilis was only slightly larger than the female, who stood at 1.2 meters and weighted in at 32 kilograms. From this observation, it is clear that there was little sexual dimorphism within the species. This characteristic bears a resemblance to modern humans, who also have reduced sexual dimorphism when compared to other apes and early hominins. In addition, there are several other characteristics that distinguish Homo habilis from earlier species. One such attribute is the hand, which appears to be a blend of ape and humanlike features. The phalanges resemble the robust and curved shape of today’s apes, yet they have broad tips and attach to the palms in a way that mirrors the modern human hand. This proves that habilis possessed the humanlike ability to form a precision grip. Some bones of the wrist and attachment sites for flexor tendons appear to be more ape-like and have been proposed to be beneficial for climbing. However, many features of the leg and food bones indicate that habilis walked on two legs. These legs were relatively short, indicating proportions that were still closer to the proportions of an ape or early australopithecine. Another feature that indicates bipedalism in habilis is the location of the foramen magnum. Its placement in the center of the skull base implies that habilis indeed walked on two legs. Research indicates that Homo habilis lived primarily in a grassland environment where the climate was becoming gradually cooler and drier. This could have established the necessity for habilis to employ new feeding strategies that utilized tools and scavenging. Upon chemically analyzing the specimens, scientists have suggested that habilis was