Biped Or All Fours?

[Guest LAL]

HairyMan,

It's possible that the site has it blocked and even though you managed to get a pdf it's not able to be shared with anyone else? Just a thought....

I guess we could pay $31.50.

From the abstract:

"We also contrast hominin, human, and ape footprints to establish morphological features of these footprints correlated with a midtarsal break versus a stiff longitudinal arch. Original photos, including stereo photographs, and casts of footprints from the 1978 Laetoli excavation, confirm midtarsal flexibility, and repeatedly indicate an associated midfoot pressure ridge. In contrast, the modern human footprint reflects the derived arched-foot architecture, combined with a stiff-legged striding gait. Fossilized footprints of unshod modern human pedestrians in Hawaii and Nicaragua unambiguously illustrate these contrasts. Some points of comparisons with ape footprints are complicated by a variable hallucal position and the distinct manner of ape facultative bipedalism."

Looks like the bottom line is the human foot is just weird.

[Hairy Man]

No, don't do that. If you want, send me your email address through pm and I'll email it.

[Guest The big grey man of ben ma]

Ancient footprints yield oldest signs of upright gait Edited February 16, 2011 by The big grey man of ben ma

[Guest vilnoori]

I saw that earlier today, too. Just a note though that the studies of gait for A. afarensis based on hip and knee morphology produced a less than perfect gait, and that the Leakey family maintained that the trackway was actually produced by H. habilis...though earlier habilines were never found. There are other works, however, that find very little difference between Lucy's gait and our own.

Here is Dr. Meldrum et al's study on this issue:

www.paleoanthro.org/journal/content/PA200407006.pdf

Another good one, http://science.jrank.org/pages/48523/Morphological-physiological-adaptations.html

Enjoy!

Edited February 16, 2011 by vilnoori

[Guest The big grey man of ben ma]

Leakey family dont know if i love them or hate them, but do respect them

[Guest The big grey man of ben ma]

They are a must read book if you have not seen it, Ape-Men: Fact or Fallacy by malcolm bowden

its totally fantastic, a scientific look at the evidence but not from the orthodox camp sure you

can pick up a second hand copy on amazon or ebay for just a few bucks, if you ever get it i would

love to hear your feedback.

My link

My link

Edited February 17, 2011 by The big grey man of ben ma

[Guest vilnoori]

expect a PM from me on that, Ben.

[Guest DWA]

On ‎9‎/‎4‎/‎2010 at 0:18 AM, Guest mizzousquatchn said:

Just starting the topic to see where everyone stands on this.... Do you believe BF can and does on occas. go to all fours for locomotion. And if so, why? Thanks!!!!

The known apes, according to those who study them, spend much more time on two legs than the uninitiated think.  Both sasquatch and yeti are frequently reported using both methods of locomotion, although for them things appear to be the reverse of what they are for the known apes, i.e., if the volume of reports  in which each mode is observed is any indicator, they appear to spend much more time upright than on all fours.

Edited May 26, 2017 by DWA

[Sasfooty]

I've seen them only a few less time on all fours than walking upright. They seem (to me) to go on all fours when they want more speed.

[Guest Cricket]

It sounds to me like the descriptions of the Bigfoot foot is the worst of all locomotor worlds.  It lacks the double arch system and the close packing of the calcaneocuboid joint of the human foot on the one hand, and while it is reported to have a mid-tarsal break (an adaptation for prehension in arboreal activity), it lacks an opposable hallux for arboreal grasping.  I just don't see how a foot like that would be able to withstand the stresses of running or sprinting as claimed in some reports (or be of much use arboreally other than standing above large branches).  If Bigfoot is an obligate biped, then that would have to impact efficiency in other modes of locomotion.  As others have noted, there are other morphological adaptations to obligate bipedalism in addition to those of the foot that would compromise quadrupedalism.  It seems to be all over the road in terms of reported capabilities, yet it is difficult to reconcile that with the reported foot features. 

[Guest DWA]

Not really.  I'd go on, but one should really read Meldrum and Krantz, both proponents...and both specialists in primate locomotor adaptations.

[dmaker]

On 5/27/2017 at 0:46 AM, Cricket said:

It seems to be all over the road in terms of reported capabilities, yet it is difficult to reconcile that with the reported foot features. 

It's almost as if it's imaginary.

[starchunk]

I would think whats most useful or convenient at the time. Like the question of nocturnal verses diurnal, I think its more about opportunism than anything so black and white.

[Guest Cricket]

On 5/27/2017 at 8:51 PM, DWA said:

Not really.  I'd go on, but one should really read Meldrum and Krantz, both proponents...and both specialists in primate locomotor adaptations.

 

Hi DWA.  This is my one post allowed in 24 hours, and I had to wait up until 1 a.m. to post it. 

I read one of Meldrum’s papers on the subject (but not his BF books) and I’ve been watching interviews and videos of him talking about his work. I recall seeing that he had a poster on his BF work at one of the AAPA yearly conferences I attended as a grad student in the late 90’s, but at the time I was working on primate hand bones for my master’s work so it just wasn’t a priority in the way that many of the other presentations and posters were. I understand his credentials, I do think he’s a very articulate and knowledgeable anthropologist, and if primary remains ever turned up I would certainly read what he has to say about them, but he is definitely not the only foot expert in the country, much less the world. I was fortunate to have studied with someone who is also a world-class primate foot expert, so I am not entirely uninitiated in the subject.

My issue with Meldrum’s assessment of the Bigfoot foot is that there is so much critical morphology that simply can’t be accessed from footprint casts, and I imagine he of course knows that. The calcaneus and the talus, for instance, each have numerous articular surfaces and features that are critical in understanding biomechanics, as well as reference points for evaluating and comparing range of motion, and you just can’t get to them from impressions of the outer surface of the foot, either at all, or in a way that is accurate enough for any secure quantification. Even when there are actual fossils from the feet of fossil taxa there can be disagreement about how the bones are oriented, leading to contrasting inferences about locomotion. So I don’t think it’s unreasonable to question the claims made for BF. How much is actually quantifiable at this point? Not very much.

As for terrestrial quadrupedalism in BF, I see that someone posted Freeman’s Low Creek knuckle print, I’m assuming as evidence of knuckle-walking. Unless there is a continuous track of knuckle prints there or somewhere else, one print doesn’t provide adequate evidence of a regular knuckle-walking component to BF’s repertoire. That one print could simply be the result of a stationary posture that any of us could engage in for a moment.  Again, the problems with a print are the limitations it imposes regarding critical internal biomechanical morphology. There are numerous features that are associated specifically with knuckle-walking, at least 17 that I know of, and by now there may be more than that. But you can’t access any of them from an impression of the surface of the hand, except perhaps the presence of knuckle pads on the fingers. Furthermore, a couple of them are in the wrist, or involve the radius, as well as muscles, ligaments, and tendons. I say all this not to entirely dismiss the existence of BF, but without primary evidence like a specimen, there are limitations to what can truly be gleaned. Even a thousand good prints still wouldn’t allow one to access that internal morphology. And a film doesn’t allow that, either.

[guyzonthropus]

Interesting points...I've read meldrum and krantzs books, and I can see validity in a good deal of what they present, but the above post does indeed pose valid question as well, largely that of uncertainty absent actual parts...

 

Not to go all hiflier(sorry buddy...) But is it a feasible thought that there might be some A&P similar to the feet of kangaroos, where in their form of locomotion resets a spring like action with every step, granting very efficient motion,  which becomes more engaged, if you will, when in a quadrupled positioning. This might in part explain the seeming disadvantages cricket finds in the foot form. I don't really know one way or another, but with the more forwardly placed ankle there's better leverage points for such motion, and in a quad position it would reduce the weight borne by the joints during locomotion and perhaps facilitate this style of movement. Just an idea, probably way off...