Bipedalism “Humans are habitually bipedal” (Du Brul 1962), “bipedalism is one of a few characteristics that separates us from our pre-human ancestors” (Jablonski and Chaplin 1992) and according to R.F. Ewer “the most important” (Ewer 1965). Ewer also makes the very obvious point that monkey’s present existence in a quadrupedal state presents us with the steep evolutionary question of “why did we evolve bipedal locomotion and monkeys did not?” (Ewer 1965) ‘Plenty of other creatures are bipedal, few are habitually bipedal, the kangaroo is one such exception, but few others exist, the main difference between us and those other non-habitually bipedal creatures is that their anatomy needed little alteration from ancestral species in order to allow for bipedal locomotion’ (Du Brul 1962). Therefore our anatomy and that of our pre-human ancestors are substantially divergent, at least those parts directly related to our upright posture (Du Brul 1962). The fact that there is such a high level of divergence with regards to the anatomy of our quadrupedal pre-human ancestors and us, bipedal humans, is intriguing. Does this speak to adaptions that weren’t initially for upright posture that eventually became useful to us as a means to more efficiently move around, or were these changes specifically for upright posture all along and if so what could necessitate such a dramatic change in our means of locomotion? (Ewer 1965) “The adaptation of a major evolutionary novelty in a population requires that the novelty confer a survival advantage and greater reproductive success to individuals in the population even during the course of its development” (Jablonski and Chaplin 1992). This tells us that the first question isn’t likely to be a plausible line of thinking if for no other reason than that the adaptations required, and present, in human and hominid anatomy are, in a fundamental way, in complete opposition to quadrupedal locomotion. The degree of anatomical divergence is evidence that something in our ancient past made bipedal locomotion, an “evolutionary novelty,” a “survival advantage” over quadrupedal locomotion and therefore granting bipedal individuals more “reproductive success” (Jablonski and Chaplin 1992). Ewer believes that the ecology of the pre-human environment at the time of this adaptation was such that it necessitated a terrestrial lifestyle rather than an arboreal one (Ewer 1965). The ecological change presumed to be the culprit here according to Ewer, and many others, is a recession of the forests, which would render a quadrupedal arboreal lifestyle impractical although not disallowing a quadrupedal terrestrial existence such as baboons, and the growth of expansive grasslands which is what finally makes bipedal locomotion a survival and reproductive advantage (Ewer 1965). The grasslands are also important for the evolution of upright posture due to it being “a habitat where bipedal walking is relatively easy and, moreover, one which confers considerable visual advantage” (Ewer 1965). Ewer points out that not all terrestrial environments make for easy bipedal travel citing the difficulty one would experience trying to traverse dense jungle or stony hillsides on only two feet (Ewer 1965). E. Lloyd Du Brul talks about another advantage of bipedal movement “Man’s body axis has been reoriented 90 degrees to the vertical position in the gravitational field, this has completely freed the hands from postural commitments to be used for food gathering and feeding” (Du Brul 1962). Ewer corroborates this with the following; “gorillas spend roughly one third of the day in a vertical position on their hind limbs with their hands freed for such tasks as feeding and grooming” (Ewer 1965). In conclusion to his
halfway mark of chimps and humans Australopithecus Afarensis Physical traits: bipedal with climbing capabilities, gracile, females are about 5 ft. while males are 1.5 ft. bigger, sloping/low heads, extended maxilla and mandible Discovery location: Ethiopia, Tanzania Associated fauna/reconstructed environ: depleting trees, afarensis have extended shoulder girdle that enables them to climb (not main form of locomotion). Their habitat couldn’t have been dense forests because they couldn’t move as…
helps provide evidence supporting evolution. The most important characteristic Lucy shares with humans is the knee joint. Lucy’s knee joint looked vaguely human, This joint was capable of locking straight up. Unlike the quadrupedal ape, Lucy was bipedal. Bipedalism has traditionally been regarded as the fundamental adaption that sets hominids apart from other primates. The term “hominid” generally means an erect-walking primate that is an ancestor of present humans. Lucy’s fossil remains provide…
be considered a hominin are bipedalism, skull features and larger brains. Bipedalism is an important characteristic to be evaluated in hominins because it was a favorable trait in locomotion when there was climate change in Africa which resulted in loss of vegetation, which made being arboreal a useless trait in locomotion in that environment. Also with bipedalism we could look at the feet of what are believed to be early hominins, and then compare it to the foot structure of an anatomically modern…
bones were rotated backwards, creating different orientation in relation to the legs and backbone in relation to the legs and backbone compared to that in apes. In male hominids, these changes to the pelvis improved the efficiency of the bipedal locomotion. But bipedal females had the complication of having to give birth to a fetus with a large head (Dean 88). The Brain: As much as the brain isn’t related to the structure of the body (in some ways), it still plays a huge part in the evolution of…
co-existed with close relatives who were more adept at climbing trees, like 'Ardi's' species, Ardipithecus ramidus, which lived 4.4 million years ago." The partial foot is the first evidence for at least two pre-human species with different methods of locomotion living at the same time in eastern Africa around 3.4 million years ago. The fossils were found below a sandstone layer. By using the argon-argon radioactive dating method, their age was estimated to be younger than 3.46 million years, "Nearby fossils…
the case of aircraft carriers. See alsoHumans (variously Homo sapiens and Homo sapiens sapiens) are primates of the family Hominidae, and the only extant species of the genus Homo.[2][3] Humans are distinguished from other primates by their bipedal locomotion, and especially by their relatively larger brain with its particularly well developed neocortex, prefrontal cortex and temporal lobes, which enable high levels of abstract reasoning, language, problem solving, and culture through social learning…
emerge around this period, leaving the serious question of how beings with restricted ability to speak communicated, the answer to which Armstrong & Wilcox suggest lies in gestural communication. They support this point by suggesting the emergence of bipedal movement in apes freed the hands for use in gesturing, a novel feature which appeared much earlier than a developed vocal tract. This provides a relatively strong case for the gradual origin of language from gesture to speech, especially in an evolutionary…
The Various Species of Chimpanzees in Africa and their Fate Chimpanzees are a species of apes that are found in a variety of different habitats in Western, Central and Eastern Africa. Their body composition is 99% similar to human beings. They are closer to human beings than they are to other primates. Like human beings, chimpanzees are distinguishable by their facial appearance, body and behavior. They are thought to be the most intelligent animals on the planet after human beings. In addition…
Anthropology-101 BONOBOS Species Origination and Geographical Distribution -The bonobo is the most recently discovered great ape in modern times. It was revealed in 1929 by German anatomist Ernest Schwarz that a skull once thought belonging to a juvenile chimpanzee was in fact a new subspecies of chimpanzee known now as the Pan paniscus, or bonobo. (Waal 6) During the Pleistocene epoch approximately 1.5 million years ago, the Congo River was formed in what is now the Democratic Republic…
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…