Introduction
Australopithecus africanus is the name given to early hominid that lived between 2 and 3 million years ago (Aiello & Dean, 1990). A. Africanus had a slender physique and is often believed to be an immediate ancestor of the present human being. Its “cranial features resemble those of human beings though the arms are slightly larger than the legs such as in the chimpanzees” (McKee, 2000: 23).
According to McHenry many fossil findings indicate that the hominid had more similarities with modern human beings than A. afarensis, Australopithecus africanus “had a cranial capacity of between 435cc and 530 cc” (1998: 5). The males of this species are believed to have had weight measuring up to 100 pounds. The females are believed to have weighed much less, approximately 50 pounds.
The body of Australopithecus africanus is comparable to that of A. afarensis only that it had longer arm and shorter legs (McHenry, 1998). This paper seeks to describe Australopithecus africanus according to: the origins or where the fossils were discovered; identify the range of places they are located on the map; identify the individual who discovered them; the actual published time range that the specimen existed; and finally identify whether there are any controversy/issues/research challenges about them.
Origins of Australopithecus africanus and the range of places they are found on the map
The “first fossil of Australopithecus africanus was discovered in 1924 in South Africa by an Australian anatomist at the University of Witwatersrand, named Raymond Dart” (Abitbol, 1995: 6). The fossil was discovered incased in limestone at a quarry in a placed called Tuang, South Africa. After it had been liberated from the limestone, the fossil resembled a young primate and thus was named “Tuang Baby” (Green & Gordon, 2008: 1).
The location of fossils of Australopithecus africanus has mainly been in the southern Africa. These places include “sterkfontein, Makapansgat, gladysvale and Tuang” which are all located in South Africa (Aiello & Dean, 1990: 56). Other areas where the fossils are believed to be located include around Lake Turkana in Kenya and Omo in Ethiopia.
The fossils discovered in Ethiopia had been categorized in another genus referred to as paraustralopithecus but were described as not being biologically valid and thus re-designated to A. africanus (Ferguson, 1987). Several other fossils have been discovered in other parts of Ethiopia and Tanzania but there have always been contentions on whether to classify them as new species or just call them A. africanus.
Time range for the Australopithecus Africanus
There are varying time ranges for the fossils of A. africanus discovered in different areas. According to Green & Gordon, current data indicates that the fossils of A. africanus “date to between 2.85 and 2.0 million years” (2008: 3). This time range has been established by a combination of different measuring techniques particularly palaeomagnetism, electron spin resonance, faunal dating and uranium lead Pickering (McHenry, 1998).
The “fossils from the Makapansgat have been found to date to between 2.85 and 2.58 million years; those from sterkfontein dates to between 2.58 and 2.00 million years and gladysvale dates to between 2.4 and 2.0 million years” (Abitbol, 1995: 5). The time range for the fossils from Tuang has been more challenging to determine and is currently being investigated at the University of Witwatersrand (McKee, 2000: 76).
Individuals who discovered the A. africanus fossils
The original Australopithecus africanus fossils found in Tuang, South Africa were discovered in 1924 by Raymond Dart who was one of the pioneers of paleoanthropology (Aiello & Dean, 1990). At the time of the discovery there were rejections from other paleoanthropologists who held a strong believed that any human ancestors must be found in Europe.
The Makapansgat A. africanus fossils were discovered by James Kitching who was one of the researchers working with Dart (McKee, 2000). According to Ferguson the fossils discovered in Makapansgat valley were originally called A. Prometheus but were later included in a single taxon (Australopithecus Africanus)(1987: 36).The fossils at sterkfontein were originally discovered by Dr Robert Broom in 1935.
Controversy/issues/research challenges about Australopithecus Africanus
The controversies surrounding A. africanus have been around since the first discovery of its fossils in Tuang, South Africa. The material was first rejected by several anthropologists who likened it to a young gorilla or chimpanzee (McHenry, 1998). In those days it was a perquisite that any human ancestor should have an “enlarged brain and an apelike jaw” and thus the hominid fossils of A. africanus were rejected. Many researchers asserted that the “Tuang child” could have grown into a chimpanzee (McKee, 2000: 103).
There has been a major debate concerning the limbs of A. africanus. The challenge has mainly focused on how to “interpret the locomotor implications of the australopith postcranial anatomy” (Green & Gordon, 2008: 2). Some scholars have asserted that the more apelike features possessed by the A. africanus should be viewed as adaptations.
Others have rejected this allegation claiming that climbing did not form a significant part of the australopith locomoter repertoire (Abitbol, 1995). According to Green & Gordon it is further difficult to link the evolutionary history of this hominid to that of the earlier Australopithecus afarensis (2008, p. 3). A. afarensis is seen to possess limb size proportions that are comparable to those of modern man and yet it is older and more primitive than A. africanus.
The assertion that A. africanus has more apelike proportions has prompted the carrying out of several studies to shed more light on that. In one study it was found that A. africanus had more human like hands though the overall proportion of limbs was more apelike than A. afarensis. However, such studies have been limited been the limited number of samples that can be of any statistical significance (Abitbol, 1995).
There are other perennial controversies surrounding the africanus material that is viewed differently by different groups. According to McKee some individuals often look at this hominid as being a “regional variation or subspecies of the A. afarensis, some look at as being a completely different species” (2000: 7).
The variations in the africanus fossils has led to the un ending debate on whether this represented more than one species, a sexually dimorphic species, or a very variable species particularly when the intra-era speculation is considered (Aiello & Dean, 1990).
Conclusion
This paper sought to describe Australopithecus africanus according to: the origins or where the fossils were discovered; identify the range of places they are located on the map; identify the individual who discovered them; the actual published time range that the specimen existed; and finally identify whether there are any controversy/issues/research challenges about them.
It has been established that A. Africanus is was the immediate ancestor of modern man and existed between 2 to 3 million years ago. The fossils were mainly discovered in South Africa by a research team headed by Dr Raymond Dart (Ferguson, 1987). It has also been established that there is a lot of controversy mainly surrounding the proportion of its limbs.
Works Cited
Abitbol, Malhotra. “Reconstruction of the STS 14 (Australopithcus africanus) pelvis.” American Journal of Physical Anthropology (1995): 143-58. Print.
Aiello, Imre and Collins Dean. An Introduction to Human evolution Anatomy. London: Academic Press, 1990.
Ferguson, Walter. “Revision of the Subspecies of Australopithecus Africanus.” Primates (1987): (2): 258-265. Print.
Green, David and Adam Gordon. “Metacarpal propotions in the Australopithecus africanus .” Journal of Human evolution (2008): 705-719. Web.
McHenry, Hillary. “Body proportions in Australopithecus afarensis and A. africanus and the origin of the genus Homo.” Journal of Human Evolution (1998): (35) 1-22. Print.
McKee, James. The Riddled Chain – Chance, Coincidence, and Chaos in Human Evolution. New Brunswick: Rutgers University Press., 2000. Print.