Lucy gets bone graft according to the reports in BBC News, ScienceNOW ScienceDaily and Nature News 10 Feb 2011, and ABC News in Science 11 Feb 2011 and Science vol. 331, p750, 11 Feb 2011. Donald Johnansen, (the palaeontologist who found “Lucy”) and two colleagues have found a foot bone they claim proves that “Lucy” and the other creatures classified as Australopithecus afarensis had an arched foot like a human foot and walked upright. One of the researchers, William Kimbel, director of the Institute of Human Origins at Arizona State University, told the BBC: “It is the fourth metatarsal bone, which resides on the outside of the middle part of your foot, and which helps support the well-developed arches of the foot that we see in the soles of modern human feet. The bone that was recovered from the Hadar site has all the hallmarks of the form and function of the modern human foot.” Carol Ward, also of University of Missouri commented: “The development of arched feet was a fundamental shift toward the human condition, because it meant giving up the ability to use the big toe for grasping branches. Our ancestors had finally abandoned life in the trees in favour of life on the ground.”
The researchers give their reason for classifying it as belonging to an Australopithicus afarensis, (the scientific name for Lucy) as follows: “This specimen was recovered from the Hadar locality AL 333 in 2000 during sieving of eroded Denen Dora 2 submember surface deposits of the Hadar Formation. Since 1975, these deposits at the 333 locality have yielded more than 250 hominin fossils that eroded from an in situ horizon dated to ~3.2 million years ago. We assign AL333-160 to A. afarensis, the only hominin species in an assemblage of >370 hominin specimens so far recovered from the Hadar Formation.”
Bruce Latimer, a palaeoanthropologist at Case Western Reserve University in Cleveland, Ohio says the bone will resolve a debate about Laetoli footprints. These are a series of footprints found in volcanic ash dated as 3.6 million years old. The prints are distinctly human-like, made by a being with an arched foot and human-like stride. Latimer commented: “When I saw those footprints being excavated, I thought, gosh, you’d lose these on a modern day beach, they have an arch and a totally human gait.” However, the prints were classified as being Australopithecine footprints because of the age of the rock, although some palaeontologists doubted they could be A. afarensis because there was no evidence it had a human-like foot. Latimer went onto say: “This work certainly puts a nail in the coffin of that argument,”
ED. COM. What is left unsaid in these articles is actually more important that what was written. Note well: the bone was not attached to “Lucy” or to any of the other bones classified as Australopithecus afarensis. It was an isolated bone. It was classified as A. afarensis only because it was found in the same sediment layer as the A. afarenesis bones, therefore the strata is dated as too old for human beings according to the preconceived evolutionary timetable.
The original report in Sciencee details the researchers’ precise measurements of the bone and its comparison with human, chimpanzee and gorilla bones. Although it is slightly shorter than the average adult 4th human metatarsal, its shape does fit the human range for all other measurements, and is distinctly different from chimp or gorilla foot bones.
We do agree the Laetoli footprints were made by the same kind of being that owned the metatarsal bone described above, but the only living contender with such a bone is the present day human being. The already held belief that human beings had not yet evolved when the strata formed, is the only reason for not believing this bone to be human. Furthermore, this bone does not confirm Latimer’s claim that this bone proves A. afarenesis made the Laetoli footprints. Laetoli is in Tanzania – more than a thousand kilometres (600miles) from Afar in Ethiopia, where the A. afarenesis fossils were found, so there is no direct connection between the Laetoli prints and the new fossil.
This is not the first time scientists have claimed a so-called “human ancestor” walked upright on the basis on one isolated foot bone. In 2001 Time magazine published an article claiming that a single toe bone proved a creature named Ardipithecus walked upright. But the toe bone was found 16km (10 miles) away from the rest of the Ardipithecus bones and since then more bones of this creature have been found which show it was an ape with flat foot and grasping toes, good for climbing trees. No retraction has been noticed in Time Magazine. (Ref. hominids, gait, ape-men)
Evidence News 16 Feb 2011