Earliest Humanlike Footprints Found In Kenya
by Christopher Joyce
http://www.npr.org/templates/story/story.php?storyId=101191786
Scientists digging in a Kenyan desert have found what they believe to be the oldest humanlike footprints. Several individuals laid them down 1.5 million years ago in what was a muddy track.
The scientists discovered not just one set of footprints, but two. The second set was left about 1,000 years after the first set. "It's incredible. I've never excavated anything like this before," says team director John Harris of Rutgers University.
Reporting in this week's issue of the journal Science, the anthropologists say the creatures that made the prints were probably Homo erectus. That's believed to be a direct ancestor of modern humans, and one that appears to have been built much the way modern humans are.
"The prints match a men's shoe size of about 9, which gives you a height of about 5 feet 9 inches," says Brian Richmond of George Washington University, who was part of the excavation team. "Here, we have really compelling evidence that they were walking with a long stride, they had an arch in the foot the way we have, and the arch puts a spring in our step, which makes walking more efficient," he says.
- posted on 02/28/2009
最后一张照片可名为踩着前人的脚印,literally:)
想起Mary Leakey发现的脚印:
Laetoli footprints, 3.7 million years ago, hominid footprints
The footprints demonstrate that these hominids walked upright habitually, as there are no knuckle-impressions. The feet do not have the mobile big toe of apes; instead, they have an arch (the bending of the sole of the foot) typical of modern humans. The discovery caused serious debate among scientists, requiring them to change their theories concerning the evolution of bipedalism.
The hominid prints were produced by two distinct individuals, or possibly three, one walking in the footprints of the other making the original tracks difficult to discover. One individual (hominid 2 in chart above) was significantly smaller, although both sizes of footprint are smaller than those of modern, adult humans. They seem to have moved at a leisurely stroll. As the tracks lead in the same direction, they might have been produced by a group, but there is nothing else to support the common reconstruction of a nuclear family visiting the waterhole together.
In addition to footprints, Leakey’s team found the remains of 13 hominids, mainly mandibles and teeth. They show similarities to the female skeleton "Lucy" from Hadar, Ethiopia. Most scholars classify them as Australopithecus afarensis, but some stress the greater similarity to the Homo genus.
--from http://www.newworldencyclopedia.org/entry/Mary_Leakey - posted on 02/28/2009
很疑惑,laetoli脚印的描述与Kenya的这个脚印非常相似? 为什么一个定位Australopithecus afarensis, 另一个定为homo erectus?这泥浆的年龄就等于脚印的年龄吗, 如何鉴定的?
找到一个note:zt如下, 照这说的, earliest humanlike foorprint应更推前?当然这书是从一个反对达尔文,creationism的出发点来写的。 撇开他的最终目的,单就脚印来说不知有否道理? 我试试会再找找其他的观点:
Laetoli Footprints:
Footnote: This information is taken from "Bones of Contention" by Marvin L. Lubenow pages 168-178.
Associates of Mary Leakey in 1978 found what appeared to be a series of human foottrails at the site G, Laetoli thirty miles south of Olduvai Gorge. The strata above them has been dated 3.6 m.y.a. and the strata below them dated at 3.8 m.y.a. There are three parallel trails, made by three individuals, with one individual walking in the footprint of another. The trails consist of 69 prints extending about thirty yards. The prints were made in fresh volcanic ash spewed out of Mount Sadiman to the east. Virtually everyone agrees that they are strikingly like those made by modern humans. This means only that the human ancestors of 3.6 million years ago had remarkably modern feet. But according to other scientists, such as physical anthropologist R. H. Tuttle of the University of Chicago, fossil bones of the known australopithecines of 3.6 million years ago show they had feet that were distinctly 'apelike.' They were incompatible with the Laetoli prints. In an article in the March 1990 issue of Natural History, Tuttle confessed that "we are left with somewhat of a mystery." It seems permissible, therefore, to consider a possibility neither Tuttle nor Leakey mentioned--that creatures with anatomically modern human bodies to match their anatomically modern human feet existed some 3.6 million years ago in East Africa.
Human Fossil Evidence Human Fossil Failure Wadjak Man HOME
Russel H. Tuttle, University of Chicago, is a specialist who has conducted the most in depth recent study of the footprints. The footprint trails at laetoli appear to have been made by habitually unshod individuals. Tuttle discovered very few studies of habitually unshod people have been done. Studies applying to shod people would not necessarily apply to the Laetoli footprints. Tuttle observed the Machiguenga Indians in the rugged mountains of Peru. He studied more than seventy individuals from ages seven to sixty seven, male and female. He concluded: "In sum, the 3.5 million-year-old footprint trails at Laetoli site G resemble those of habitually unshod modern humans. None of their features suggest that the Laetoli hominids were less capable bipeds than we are." Tuttle also writes: "In discernible features, the Laetoli G prints are indistinguishable from those of habitually barefoot Homo sapiens." In describing the similarity of the Laetoli prints and those of the Machiguenga, he writes: "Casts of Laetoli G-1 and of the Machiguenga footprints in moist, sandy soil further illustrate the remarkable humanness of Laetoli hominid feet in all detectable morphological features." Furthermore, he rejected the notion Laetoli footprints were made by Australopithecus afarensis, but he found the work on the footprints by J. T. Stern, Jr., and Randall L. Susman (State University of New York), was flawed: "In any case, we should shelve the loose assumption that the Laetoli footprints were made by Lucy's kind, Australopithecus afarensis. The Laetoli footprints hint that at least one other hominid roamed Africa at about the same time. ...my studies on the Laetoli footprints provide no support for the apish model of Stern and Susman, who, in fact, waffled from their initial position on the basis of undocumented rumors about the faults in the casts that they studied."
If the Laetoli footprints are so much like those of modern humans, why would Tuttle talk of existence of another 'hominid'? Why not ascribe the footprints to a member of the genus, Homo? He honestly gives the answer: "If the G footprints were not known to be so old, we would readily conclude that they were made by a member of our genus, Homo." The real and only problem is that to ascribe them to Homo does not fit the evolutionary scenario. A typically classic evolutionist case of intrepreting the facts according to their preconceived philosophical bias. The Kanapoi KP 271 fossil is ascribed the same intrepretation by William Howells. According to evolutionist theory, the elbow bone is too old to be human: "The humeral fragment from Kanapoi, with a date of 4.4 million, could not be distinguished from Homo sapiens morphologically or by multivariate analysis by Patterson and myself in 1967(or by much more searching analysis by others since then). We suggested that it might represent Australopithecus because at that time allocation to Homo seemed preposterous, although it would be the correct one without the time element." Why do evolutionists refuse to call extremely old fossils by their correct name? The reason is to protect evolutionary theory even at the cost of damaged science.
- posted on 02/28/2009
草叶,原文在这里:Early Hominin Foot Morphology Based on 1.5-Million-Year-Old Footprints from Ileret, Kenya 当初Laetoli脚印的:Pliocene footprints in the Laetolil Beds at Laetoli, northern Tanzania
我想脚印的年龄和泥浆的年龄应当是一样的吧,这个不象别的化石能动地方,怎么鉴定的最好老尚能来给讲讲,不过咱不一定能招呼得来 :)
脚印所属我看Leakey文章里主要是说同时发现的骨骼化石比较象Lucy但还要早一些,没下结论。
这个新脚印的我ZT下:
The Ileret footprints show the earliest evidence of a relatively modern human–like foot with an adducted hallux, a medial longitudinal arch, and medial weight transfer before push-off. Although we cannot conclude with certainty what hominin species made the footprints at FwJj14E or GaJi10, these modern human characteristics, in combination with the large size of the prints, are most consistent with the large size and tall stature evident in some Homo ergaster/erectus individuals (19, 20).
文章里也把新脚印和Laetoli脚印做了量化比较和clustering,结论是离现代人近离Laetoli远,不过具体那些解剖特征我也不懂。你要是相信这些参数的说服力,那Laetoli脚印和现代人的就不是上文说的:Tuttle also writes: "In discernible features, the Laetoli G prints are indistinguishable from those of habitually barefoot Homo sapiens."
- Re: ZT: Earliest Humanlike Footprints Found In Kenyaposted on 02/28/2009
这一线开初咱也想起Laetoli(还是自然史博物馆的地板上的呢),就被
浮生好奇先了。草叶的纳闷也真,只是,尚大人孔乙己还不露面,咱
先提个人类学作伪的可能性,或者按古典的意思,忽悠一下百姓。
好象前几年也有不少脚印的发现。唉,这帮人,挖脚印一行!(记得贾
兰坡说百姓骂"他们"是掘祖坟的人:-) - Re: ZT: Earliest Humanlike Footprints Found In Kenyaposted on 03/01/2009
Fusheng, Thank you, I know you can dig out the facts. ButI don't have code to read the articles. :(
- Re: ZT: Earliest Humanlike Footprints Found In Kenyaposted on 03/01/2009
草叶,send me an E at fushengcf@gmail.com, I'll forward you the PDFs.
xw怀疑一切哈,这组脚印06年发现的,觉着要是忽悠好像可以快一些似的 :)
- posted on 03/01/2009
多谢, 浮生。
我看到下面这篇文章, 他们觉得bipedalism的进展很可能是马赛克的而不是线性的。尤其在early homonins。可能直立行走的起源,形式和机能都不是单一的, 而是多样化的。
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1571304
Recent discoveries of taxa such as Kenyanthropus platyops, Sahelanthropus tchadensis, Orrorin tugenensis and Ardipithecus ramidus kadabba suggest a far wider degree of taxonomic diversity in the African fossil hominin record than had previously been thought (Fig. 1) (Haile-Selassie, 2001; Leakey et al. 2001; Senut et al. 2001; Brunet et al. 2002; Wood, 2002). At present, craniodental remains almost exclusively support the evidence for this diversity. Based on this inferred diversity and supported by the existing evidence for postcranial diversity, it is not unreasonable to assume that there was also a considerable degree of locomotor diversity in the early hominins. As has been shown, the prevailing view in the earlier literature on the evolution of bipedalism has been a particularly linear one, with the usual pattern being a neat series of steps from arboreal quadruped to obligate biped. As more fossil evidence accumulated, some researchers entertained the possibility of locomotor diversity in contemporary early hominins (e.g. Napier, 1964), but this view was far from prevalent. Furthermore, many of the more recent studies, informed by the growing collection of hominin postcranial fossils, have focused on the degree to which particular skeletal elements imply one type of locomotion or another.
The central point is that contemporary fossil taxa may well have been mosaic in their adaptations, but, critically, may have been mosaic in different ways to each other. This has recently been shown to be the case for the feet of A. afarensis and the new and similarly aged A. africanus specimen ‘Little Foot’ (Harcourt-Smith, 2002). Further analyses of other skeletal elements are needed to reinforce this interpretation. If correct, this would imply that there was more locomotor diversity in the fossil record than has been suggested, and raises questions over whether there was a single origin for bipedalism or not. At the very least, if bipedalism appeared only once in the hominin radiation and is therefore monophyletic, such evidence would suggest that there were multiple evolutionary pathways responding to that selection pressure. It is currently difficult to determine primitive from derived morphologies in the hominins because of the problem of homoplasy and resulting phylogenetic uncertainty. Although perhaps controversial, it is important that when considering such a unique adaptation as bipedalism, we do not allow that uniqueness to imply that there was ever only one successful mode of bipedalism in our hominin ancestry. In light of the richness of recent findings in the hominin fossil record, it is important to ask the question of whether the evolution of bipedalism was a more complex affair than has previously been suggested.
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