What are the various human ancestors?
Australopithecus ramidusAustralopithecus ramidusis the most recent additionto the human evolutionary tree; see [Boyd & Silk 1997] (pp 359-361). In 1994, fossils were found by Tim White and his associates [White et al. 1994] in the Middle Awash region of Ethiopia. They subsequently named A. ramidus, a new hominid species, though it has recently been changed to Ardipithecus ramidus. The collection of 17 fossils includes dental, cranial and postcranial material, and is dated to around 4.4 million years ago, making it the remains of the oldest known hominid. The features include small canines (like humans) and thin tooth enamel (an African ape characteristic). They were found near Hadar where A. afarensis was found. Preliminary palaeogeographical reconstruction suggests that the habitat was woodland. The mode of locomotion is not yet known. Molecular and fossil evidence suggests the split between the great apes and humans was between 5-8 million years ago, so these remains are close in age to the divergence. The collection has been dated at around 4.4 million years old.
These questions have yet to be answered. |
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 Australopithecus afarensis |
Australopithecus afarensisA reconstruction of Australopithecus afarensis based on the fossil finds from Hadar in Ethiopia, particularly the partial skeleton known as "Lucy"; see [Boyd & Silk 1997] (pp 342-359). The Hadar remains (3 my BP) and the footprints at Laetoli (3.7 my BP) are thought to represent the same species. |
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Australopithecus africanus (Sts 5)The cranium of a female australopithecine(Australopithecus africanus) found at Sterkfontein in South Africa. |
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Australopithecus robustus (SK 48)The some what crushed cranium of a robust australopithecine(Australopithecus robustus) from Swartkrans in South Africa (probably a female). |
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Australopithecus boisei (OH5)The cranium of a large robust (probably young male) australopithecine (Australopithecus boisei) found by Mary and Louis Leakey at Olduvai Gorge, Tanzania in 1959. The mandible does not belong to this specimen, but is added to show how well it fits despite being recovered from another East African site (Peninj). First named "Zinjanthropus boisei" by the Leakeys, it is about 1.7 my old; see [Boyd & Silk 1997] (pp 370-372). |
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Australopithecus aethiopicus (WT 17000)The remarkable "Black Skull" (Australopithecus aethiopicus) found in 1985 at a site on the western side of Lake Turkana in Kenya. In many respects it resembles Australopithecus boisei from Olduvai, but in others it is resembles Lucy, Australopithecus afarensis, from Hadar. Its age surprised everybody - 2.5 million years BP, much older than A.boisei. Hence many prefer to call it A.aethiopicus. See [Boyd & Silk 1997] (pp 372-373). |
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Homo habilis (KNM-ER 1470)This cranium was put together from fragments found at Koobi Fora on the eastern side of Lake Turkana (1.9 my BP); see [Boyd & Silk 1997] (pp 373-377). It is notable for its more "human" face and comparatively large endocranial cavity, suggesting a brain size of about 750 ml. Most palaeo-anthropologists classify this specimen as Homo habilis, but some suggest that this specimen might be a species in its own right - Homo rudolfensis [Wood 1992] . |
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Homo erectus (KNM-ER 3733)An almost complete cranium from Koobi Fora on the eastern side of Lake Turkana, Kenya (1.6 my BP); see [Boyd & Silk 1997] (pp 428-435). One or two palaeo-anthropologists believe this specimen is distinct enough from later H. erectus to warrant a separate species [Wood 1992] . They refer to it as Homo ergaster. Most others include it within Homo erectus. |
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Archaic Homo sapiens (Steinheim)This skull was found in 1933 at a quarry near Stenheim in Germany. It is regarded as an early female sapiens. Similar in many respects to the Swanscombe remains found in Britain, these are dated at about 250-300,000 years BP; see [Boyd & Silk 1997] (pp 448-450). |
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NeanderthalsNeanderthals have long been a problem group; see [Boyd & Silk 1997] (pp 450-455). This is the cranium from La Chapelle-aux-saints in France (47-56,000 yr BP), a fossil notorious for the way it misled anatomists about neanderthal posture and intelligence. This individual suffered from osteoarthritis - hardly surprising therefore that he walked with a stoop and died young - thus misleading anatomists about neanderthal posture and intelligence [Stringer & Gamble 1993] . Once classified as Homo neanderthalensis, they are now more commonly referred to as Homo sapiens neanderthalensis, though the original name is now creeping back. However, neanderthals first appeared some 230,000 years ago and died out 30,000 years ago.
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Human Skull (Modern)Anatomically modern humans have a number of features that distinguish them from their predecessors; see [Boyd & Silk 1997] (pp 464-467).
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