More fossils of human ancestors found in athiopia

Humans originated in africa and their lineage is becoming increasingly clear. New finds of hominid bones of the genus australopithecus in the afar depression in eastern ethiopia shed light on the early history of the ancestors of modern humans.

In the scientific journal nature, tim white of the university of california at berkeley and more than 20 colleagues from scientific institutions in ethiopia, japan, france and the usa, who are involved in the middle awash project, publish the report on the analysis of the australopithecus finds discovered in aramis and asa issie, only ten kilometers away in the ethiopian afar depression, 230 km northeast of addis ababa (cf. Asa issie map).

Idea of the appearance of australopithecus, image: nasa

82 years ago, anatomy professor raymond dart in sud africa classified the skull of the so-called taung child as australopithecus, derived from the latin australis "south" and the ancient greek pithekos "monkey". His discovery was controversial for a long time and it took a while before, after further discoveries, the realization that the southern ape actually belonged to the pre-humans, the hominids, prevailed.

The classification of hominids is now disputed by some experts, but in general the term is still used. Hominids are members of the family hominidae (human-like), which includes all living or extinct creatures that are more closely related to homo sapiens than to the ape. The chimpanzee is the closest relative of man, we share over 99% of our genes – now there is even a debate about whether this ape is not much more human than gorillas and orangutans.

Ancestry

Several different australopithecines are now known, and some are still under discussion – some have been reclassified after new fossil discoveries in the last twenty years, such as australopithecus ramidus, which is in fact a new genus and has accordingly been placed in ardipithecus ("ground root ape") was renamed (cf. New traces of a distant relative).

The oldest of the australopithecines is australopithecus anamensis, whose bones were first found in 1994 by meave leakey in northern kenya, in the turkana basin. The southern sea ape ("anam" is the turkana word for "lake"), lived 4.2 – 3.9 million years ago and has anatomical features that make it appear humanlike. It is an ape-man, small in stature and with coarse teeth, which at first sight looks more like an ape, but already walked upright and whose extremities make him appear as a pre-human being.

Fossils of this early member of the human ancestry were found and studied in detail by tim white and colleagues in ethiopia from 1994 to the end of 2005. Three hundred fossils, mostly teeth but also parts of femurs, hands, and bones of australopithecus anamensis, were recovered at asa issie from at least eight different individuals. Among other things, a maxillary bone with teeth was discovered in aramis.

Some of the fossilized bones found, especially the extremities, are very similar to those of the younger hominid australopithecus afarensis, whose best known representative is lucy, whose skeleton was also found in the afar depression in 1974.

Teeth of australopithecus anamensis. Photo: david l. Brill\brill atlanta

The new finds from athiopia have been dated to between 4.1 and 4.2 million years old using palaomagnetic and argon-argon methods.

Further hotly debated is certainly the extended phylogeny of the hominids, or. The relationship of ardipithecus and australopithecus anamensis. Tim white boldly declares, "the new discovery closes the gap between the entire australopithecines and earlier forms we call ardipithecus. We now know where australopithecus came from four million years ago."

New ape-men

two hypotheses about the lineage of hominids and humans. Illustration: human evolution research center, uc berkeley

In the effective scientific evaluation he is much more cautious and, together with his colleagues, puts forward two hypotheses, one constructing a direct lineage between ardipithecus and australopithecus, the other a branching in which both hominid species existed side by side. More fossils of both ancestors of man will be needed to finally answer the unanswered questions.

The site in ethiopia, where fossils of various types of early humans have been found – from the 5.7 million year old ardipithecus kadabba (cf. The return to the planet of the apes) to early homo sapiens – is promising and could hold many more surprises.

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