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Ancient Foot Bone Proves Prehuman Lucy Walked Tall…


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Ancient Foot Bone Proves Prehuman Lucy Walked Tall… Hmmm Lucy - Patty - Lucy - Patty - Lucy

No tip-toeing around it, this foot bone could change the story of human evolution -- or at least the story of human foot evolution.

The bone is additional evidence that Australopithecus afarensis, an ancient human ancestor who lived around 3 million years ago, spent most of its time walking, instead of climbing trees like chimps.

"Lucy and her relatives were bipedal, but there had been a debate as to how versatile they were in the trees," said lead researcher Carol Ward, at the University of Missouri in Columbia, referring to the most famous A. afarensis member nicknamed Lucy after a Beatles song. "If they did climb in the trees, they wouldn't have been able to do it any better than you or I would."

One human origins expert doesn't buy the conclusions, however, saying other Lucy-aged bones point to a combination of tree climbing and ground walking.

Foot bone

The bone in question belonged to one of Lucy's A. afarensis kin who died about 3.2 million years ago. It was discovered in Hadar, Ethiopia, on a plateau so rich with fossils from this era that it's called the "first family site."

The bone comes from the outside of the foot, near the pinky toe, and is a stiff part of the arch bone that acts like a lever when walking on two feet.

Arches were an important part of our evolution into humans, because they make climbing trees much harder. The arches on the inside of the foot, nearer to the big toe, serve as a shock absorber when we plant our feet back on the ground. All other living primates have feet made for grasping and bending to hang onto tree branches and their young, more like our hands than our feet.

Their analyses revealed the bone matched up best with human foot bones, suggesting, Ward said, that Lucy and her Australopithecus kin would have spent time in the trees only when chased there by predators or to harvest food from its branches. "Selection wasn't favoring the ability to be effective in the trees, it was favoring being effective on the ground," Ward said.

"That's a big deal because those means arches, and not just precursors, real full-grown arches go back three, three and a half million years," said Jeremy DeSilva, from Boston University, who was not involved in the study. "It really helps us understand this uniquely human feature, this arch."

Down from the trees

An inkling of Lucy's saunter came in 1976, when scientists discovered footprints in volcanic ash left behind 3.5 million years ago by three creatures in Laetoli, Tanzania. Though the footprints had distinct arches, figuring out who made them was tricky and has been long debated in the archeological world.

And only a few arch bones from early humans have been found, making it difficult to determine if Australopithecus had arches.

"Those of us who work on feet and early human foot morphology, arches have been tough because they are soft tissue, and they don't really fossilize," DeSilva, who studies locomotion in the earliest apes and early human ancestors, told LiveScience. "What you look for are skeletal hints, or correlates of the presence of an arch, and as a field we haven't really been able to agree on what those are."

Scientists don't have a very clear grasp on how bones evolve, either, DeSilva said. Use of bones during movement can shape the bone scaffolding laid down by genes during development. And so it's hard to isolate features of these fossilized bones that would've been the result of the walking styles of a few individuals versus an adaptation that evolved in a group of organisms.

But previous studies of ankle toe and heel bones convinced DeSilva. "I wouldn’t say that from a single metatarsal [foot bone] you can reconstruct the entire locomotion of an animal, but from all of the other evidence that's been presented from the waist down, they were obligate walkers," DeSilva said.

"These things are moving very similar to the way we are, the way we do today and they were not spending much time up in the trees," DeSilva said, though he noted that there are differences in the pelvic region that suggest Lucy and her kin might have walked with a slightly different gait.

Or still hanging around?

But this new evidence hasn't swayed everyone.

William Harcourt-Smith, from the City University of New York and the American Museum of Natural History, disagrees with Ward and DeSilva. Though he said the analysis of the bone is well-done, he still believes that Lucy could have spent as much as 50 percent of her time climbing, and would have been comfortable in the trees.

"You look at this one bone, it looks very humanlike, and you can't disagree with the analysis, but it only tells part of the story," Harcourt-Smith told LiveScience. "If you want to know how it [Australopithecus] walked around you have to look at all of the evidence available."

Harcourt-Smith also notes that a bone from the inside of the foot, where the arch is the strongest, would be more convincing. When Harcourt-Smith looks at other parts of Australopithecan anatomy, including its curved toe bones and another foot bone called the navicular bone, he comes to different conclusions.

"It [Ward's bone] is obviously quite humanlike," Harcourt-Smith said. "But you look at the other bones and you have a mosaic of adaptive features," meaning features for tree climbing as well as walking on the ground.

DeSilva notes that Australopithecus does have climbing adaptations, including indications of a strong upper body, which would have encouraged climbing, but which he said could also be used as adaptations to carry food or babies when walking on two feet.

"They have their own interesting adaptations and anatomies and peculiar ones which have been difficult to figure out if they are evolutionary carryovers or if they are adaptations," DeSilva said. "These are not scaled-down humans."

An analysis of the bone will be published in the Feb. 11 issue of the journal Science.

Read more: http://www.foxnews.c.../#ixzz1F3wRL6Rr

Edited by TooRisky
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It certainly has relevance. Many make the argument that bigfoot is an ape because it lacks an arch.

I do agree that their conclusion is probably just speculation. It is hard to account for floresiensis with a flat and relatively very long foot and then assume that an arch is critical to walking on the ground and evolved so early. That just doesn't make sense in the slightest. I could see them saying that an arch might help long distance running but to imply that it means they don't spend time in trees... I'm missing something in that line of reasoning.

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This has everything to do with bigfoot. The midtarsal break is an arboreal feature. what this is saying is that this bone from afarensis was more humanlike instead of apelike, indicating an arch, which would mean it didn't have a midtarsal break. The midtarsal break theory in bigfoot is contentious both because there is no foot to see if it has an arch or not, but also because it is heavily argued and evidence weighed that hominids either developed an arch when they became bipeds or had no real arch but no midtarsal break, or did retain a midtarsal break.

If afarensis had an arch likely it spent way more time on the ground, and only in the tress to evade a predator or to reach some food. Developing the arch would lose the break, indicating it spent more time on the ground, according to the authors.

Edited by wolftrax
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Guest TooRisky

This just proves one thing... Once a skeptic there is no turning back, no matter the evidence that is put forward... So regardless of the post, picture, or video the skeptic will always claim something is tainted... regardless if it is science fact or not the very subject of having a unknown Bipedal walking creature in the woods is just to much for them to except like an ostrich sticks their head in the sand pretending to not see what is in their face...

For the above reason I really would like a section dedicated to the constructive conversation of the species known as Sasquatch where we believers can finally speak without being ridiculed or steered in the conversation by someone who really has no business being here other than to disrupt the train of thought for those that do...

It would simply put those that believe in their own sub-forum with a Moderator that has the ability to decide who is a non believing disruptive person and show them the door back to the forum... This is really not much that I am asking, totally feasible and non discriminative yet keeps a realm of cohesive conversation going without the disruptive nay sayers...

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Guest BitterMonk

...someone who really has no business being here...[/font]

Every member that abides by the posting guidelines and rules has a right to be here and participate in any discussion in any manner that they see fit.

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Guest TooRisky

Again totally missing the point and fruitless to discuss this with because BM you are one of who I speak... No offense, for you have every reason like the next to disrupt conversation that you do not believe in, disregarding the flow of conversation or the evidence provided... Thus my asking for a sub-forum free of disruptive nay sayers... I did say a Sub-Forum, not The Forum...

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Guest BitterMonk

That's great, considering that you don't know me, my history, what I've experienced or been through, or what I do or don't believe in. Way to widen the brush there.

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masterbarber
Admin

The only person that appears to be disrupting anything is the OP. Now stop taking pot shots at folks and please get back on topic or this thread will be shut down. Thank you in advance for your prompt attention.

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Guest Blackdog

Again totally missing the point and fruitless to discuss this with because BM you are one of who I speak... No offense, for you have every reason like the next to disrupt conversation that you do not believe in, disregarding the flow of conversation or the evidence provided... Thus my asking for a sub-forum free of disruptive nay sayers... I did say a Sub-Forum, not The Forum...

You really have no idea who or what Bitter Monk is, do you?

There is a Sub-Forum for members sightings and I don't think there has been a skeptic who has disturbed that. The mods are taking care of that.

If you don't like the skeptical arguments I would suggest you do a better job of disputing them instead of complaining about them.

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The conclusion that it takes an arch to be bipedal is simple minded and it ignores hominids that don't have an arch. It isn't just simple minded from ignoring actual hominids that don't have an arch, it is like the author with that opinion has no comprehension about the subject that they are discussing and see the single model of the human foot as the only model that could work. With all the other feet out there in the animal world, that is amazingly narrow minded. It reminds me of some scientist quoted on the old BFF that said something to the effect that bigfoot would have the same problems that modern humans with fallen arches would have if it had flat feet. That was supposed to be an argument against the existence of sasquatch. It is like those people have zero comprehension of basic biology and no clue how evolution works. I am trying to cut them some slack but frankly it sounds to me like someone trying to make a big deal out of his fossil by seeing or inventing something that isn't even there. Either that or they lack the capacity to understand basic biology and simple mechanics. Sorry, I guess I am getting irritated by "scientists" with agendas. The part that really irritates me is the silly notion that an arch on the foot is what defines bipedalism and without it, it is a tree dweller. They are anthropomorphizing all hominid feet as if they are just underdeveloped modern human feet.

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Hairy Man

Meldrum et al just published a paper that contradicts the paper cited above. It can be found here in full, since I still can't upload things.

Edit: Big thumbs up BobZenor!

Edited by HairyMan
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kitakaze

This has everything to do with bigfoot. The midtarsal break is an arboreal feature. what this is saying is that this bone from afarensis was more humanlike instead of apelike, indicating an arch, which would mean it didn't have a midtarsal break. The midtarsal break theory in bigfoot is contentious both because there is no foot to see if it has an arch or not, but also because it is heavily argued and evidence weighed that hominids either developed an arch when they became bipeds or had no real arch but no midtarsal break, or did retain a midtarsal break.

If afarensis had an arch likely it spent way more time on the ground, and only in the tress to evade a predator or to reach some food. Developing the arch would lose the break, indicating it spent more time on the ground, according to the authors.

Well said, Wolf. This is simply confirmation that when apes evolve bipedalism, the evolve arches to facilitate that mode of locomotion and economize the use of energy. Australopithecus afarensis was not human, though it was almost certainly an ancestor of humans. The midtarsal break idea with Bigfoot seems concocted solely as a pseudoscientific method of explain the byproduct of wearing stompers.

This would be a good time to review the arguments against Meldrum's midtarsal break idea by Dr. Richard Eisner...

http://www.blogtalkradio.com/bigfoot_quest/2008/08/13/bigfoot-quest

Meldrum supporters will likely dismiss Eisner since he specializes in human feet, but as Lucy shows us, the arch is a necessary adaption by all known bipedal apes including humans (for those who think humans are not apes).

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