Ancient Foot Bone Proves Prehuman Lucy Walked Tall…

[Guest vilnoori]

Personally speaking I think the Grays Harbor track is very similar to the H. erectus one from Kenya. Interesting. And actually there is indeed a midtarsal break, but it is formed from a higher arch than normal.

[Guest LAL]

OK have a look at this comparison I made, using photos of footprints online. Some have been "mirrored" so as to all show the left foot, and they have been changed in size to all look the same. However the Laetoli tracks were very small (a small parent and even smaller child, actually) while the Gray's Harbor, WA bigfoot track is very large, over 14 inches and still retains an arch. Mr. V is a size 10. I in no way confirm that the purported Bigfoot tracks are of a real Bigfoot but they look pretty good, better than what is being used by others to represent Bigfoot tracks on this thread.

Keep in mind that humans have a natural arch at certain times in life, and lose it at other times in life, and also it varies with individuals and weights. I would assume the same to be true of other humanlike creatures. We can't assume anything. The neanderthal footprint was large and wide, and yet clearly shows an arch, while the Laetoli track was small and slim, but does not show an obvious arch. In fact it is a very unusual type of foot with the big toe diverging from the rest of the toes and a very pronounced left side to right side arch (and not very much back to front).

My apologies if I have not cited properly, I sometimes pick up these pics online without noting where they are from. Please feel free to fill in the missing info. I'm not sure where the first BF print is from.

Here's another for the collection from Dr. Meldrum's WCS 2003 presentation:

[Guest LAL]

Walking is OK but humans, according to some recent insight, are designed for endurance running. Here's a TEDtalk video that sheds some light on what could our ancestral heritage of endurance running, and how it shaped us, and maybe our common ancestor with BF like creatures if they are in fact relic populations of hominins and not pithecine apes.

http://www.ted.com/t...orn_to_run.html

Running was a good thing when you were prey. Oreopithecus' tripod foot wasn't useful when the island was no longer an island and predators moved in.

[Guest BitterMonk]

I'm not sure where the first BF print is from.

That's a photograph I took of a track find in 01.

[Guest vilnoori]

Thanks, Bittermonk. Do you consider it a bona fide sasquatch track, or possibly a human? It has a remarkable mid-tarsal break! Note that the midtarsal break falls on a diagonal on the foot. In the Gray's Harbor track it also falls on the diagonal, but is more curved overall. They are remarkably similar. And what is the coincidence that the H. erectus track from Kenya also shows such similarity? I never noticed it before I lined them all up like that. The narrow foot, the exceedingly high arch (way higher than ours, perhaps the cause of the so-called mid-tarsal break)?

I'm currently reading the Hominid Gang by Delta Willis and she mentions the structural differences between H. erectus and ourselves. The Turkana Boy pelvis was even more running-adapted than our own, and they posited that the females did not have the adapted pelvis that ours have, to give birth to large-brained babies, but rather were the same as the males (though, it seems, the females were smaller and more gracile). What are the chances that they have a "super arch" in the foot, as well? Is this what we are seeing in younger sasquatches? Does it change as they grow larger, the giant adults' weight pressing it down flat but a break remaining in some tracks?

[southernyahoo]

Personally speaking I think the Grays Harbor track is very similar to the H. erectus one from Kenya. Interesting. And actually there is indeed a midtarsal break, but it is formed from a higher arch than normal.

There is also a similarity between neanderthal and BM's photo, the golfball-like bigtoe impression.

[masterbarber]

That's a photograph I took of a track find in 01.

Where's the photo of the stomper?

[Guest vilnoori]

Delta Willis writing in 1990 mentions the curved foot bones of afarensis, so it was already a given. I'm not really sure why this is suddenly news. Curved foot bones do not a high arch make, as Bob mentioned, it has a lot to do with the way the foot is packaged by the tendons. The Laetoli tracks do not show the same kind of arch as modern feet, yet it is an efficient way of walking as far as we can see. Flat footed humans seem to have no difficulty walking, though running a lot may be a different story.

Floresiensis is commonly accepted now as being an earlier derivative than erectus, probably something comparable to the habilines. Why is it such a problem to consider that these earlier forms of hominins were in Asia, Bob? After all, macaques are in Asia, gibbons, orangs, erectus, archaic and modern humans are all present in Asia! To me it makes sense that it would be there too. There is a clear pattern of successive bursts of migration out of Africa all along the evolutionary pathway from monkey to modern human, perhaps coinciding with climatic fluctuations, sea level changes associated with glaciation cycles or whatever.

Edited March 1, 2011 by vilnoori

[BobZenor]

...

Floresiensis is commonly accepted now as being an earlier derivative than erectus, probably something comparable to the habilines. Why is it such a problem to consider that these earlier forms of hominins were in Asia, Bob? After all, macaques are in Asia, gibbons, orangs, erectus, archaic and modern humans are all present in Asia! To me it makes sense that it would be there too. There is a clear pattern of successive bursts of migration out of Africa all along the evolutionary pathway from monkey to modern human, perhaps coinciding with climatic fluctuations, sea level changes associated with glaciation cycles or whatever.

It isn't a problem for me. I accept that as probably a given. There is no reason in the real world that floresiensis couldn't have split off our lineage that long ago. There isn't a whole lot of gracile australopithicine evidence even in Africa beyond about 2.5 million years ago. Being gracile makes it more likely they would compete with gracile Homo. They certainly could have existed in Africa beyond 2 million years ago and made it to Asia even earlier. It still would be rather surprising for one that distantly related to have escaped the fossil record and for it to have made it to Indonesia. Maybe they were largely forest dwellers where fossils are much rarer. Maybe some of the "erectus" are really that badly miscategorized. I never had a problem with the idea of older hominids living in Asia. It was just the lack of paleontologists suggesting it. Saying that floresiensis might be much more distantly related is only halfway there. They need to finish and say that it suggests that a much more distantly related lineage existed in Asia.

Edited March 1, 2011 by BobZenor

[wolftrax]

some excerpts from the paper:

The transition to full-time terrestrial bipedality is a hallmark of human evolution. A key correlate

of human bipedalism is the development of longitudinal and transverse arches of the foot that

provide a rigid propulsive lever and critical shock absorption during striding bipedal gait. Evidence

for arches in the earliest well-known Australopithecus species, A. afarensis, has long been debated.

A complete fourth metatarsal of A. afarensis was recently discovered at Hadar, Ethiopia. It exhibits

torsion of the head relative to the base, a direct correlate of a transverse arch in humans. The

orientation of the proximal and distal ends of the bone reflects a longitudinal arch. Further, the

deep, flat base and tarsal facets imply that its midfoot had no ape-like midtarsal break. These

features show that the A. afarensis foot was functionally like that of modern humans and support

the hypothesis that this species was a committed terrestrial biped.

Although Australopithecus afarensis was

primarily a terrestrial biped, there continues

to be debate over the nature of its

bipedality and the extent to which its morphology

represents a compromise between terrestrial bipedality

and arboreal locomotion. One of the key

adaptations to a human-like striding bipedal gait

is the evolution of permanent transverse and longitudinal

pedal arches (1, 2). The arches, supported

by bone and soft tissue, provide an important

mechanism for shock absorption during the stance

phase of gait (3) and a rigid lever at heel-off, as

well as permit flexibility during locomotion at

different speeds and across irregular terrain (3–6).

Muscles that in apes adduct the hallux (such as

them. adductor hallucis and m. fibularis longus), in

humans primarily support the pedal arches (1, 5).

Permanent plantar arches are a key component of

human bipedal walking and running because

they contribute to the rigidity of the foot and provide

an enhanced mechanical advantage during

the propulsive phase of gait (1, 7–9). Extant apes,

in contrast, exhibit pronounced midtarsal dorsiflexion

during heel-off as a result of a mobile

midfoot, which permits flexibility for negotiating

variably oriented arboreal substrates [(8, 9) and a

recent review in (10)]. This break is greater in

magnitude and is kinematically and anatomically

distinct from the medial collapse seen in some

humans (7, 11, 12). Therefore, determining the

extent to which the foot of A. afarensis had

permanent longitudinal and transverse pedal arches

is key to deciphering the extent of its commitment

to terrestrial bipedality.

In AL 333-160, the metatarsal head is twisted

laterally relative to the base, producing shaft torsion

characteristic of modern humans (2) and later

fossil hominins, including Homo habilis specimen

OH 8 (22, 23) and the H. erectus foot bones

from Dmanisi, Republic of Georgia (24). This

torsion contrasts with the ape condition, in which

the head and base exhibit minimal relative rotation

(Fig. 2). Torsion allows the plantar surface of

themetatarsal head to contact the ground in a foot

with a strong skeletally supported transverse arch

(2, 25, 26), an everted posture characteristic of a

foot adapted for the modern human terminalstance

phase of gait, rather than the inverted foot

postures of apes used in climbing. This degree of

torsion of the AL 333-160 metatarsal demonstrates

that a permanent bony transverse arch must

have been present in the foot of A. afarensis.

In AL 333-160, the diaphysis is angled plantarly,

rather than dorsally, relative to the base, as

in humans and H. habilis [OH 8; see (11)] and

unlike in African apes (Fig. 3). This morphology

further indicates a permanent longitudinally arched

posture of the foot, because the fourth metatarsal

makes an angle of about 8° to the ground in a normal human foot (5). The metatarsal head in

AL 333-160 is flattened along the plantar portion

of its articular surface, which faces distally

relative to the diaphysis rather than being parallel

to the diaphysis as in extant apes, forming a

large plantar surface-diaphyseal angle (Fig. 3).

This reflects the overall more extended posture

of the metatarsophalangeal joints in the hominins

(2, 5, 23).

The AL 333-160 head exhibits another set

of distinctive hominin apomorphies observed also

in Ardipithecus ramidus (25), Australopithecus

(14, 19, 27), and later hominins [reviews in (1, 22)].

It is domed dorsally in medial and lateral views

(indicated by arrows in Fig. 3B), and there is a

deep transverse gutter along the dorsal margin

of the subchondral surface. In chimpanzees and

gorillas, the domed portion of the head inclines

plantarly, reflecting habitual loading in flexion.

The hominin configuration seen in AL 333-160,

and also in the AL 333-115 partial metatarsals

(14, 19), would allow an increased range of dorsiflexion

at the metatarsophalangeal joint as compared

with apes, as well as habitual loading of the

joint in extended postures that occur during the

push-off and terminal phases of striding bipedal gait.

The lateral column of the human midfoot is

relatively stiff, so that the mid- and hindfoot lift

off the ground during gait simultaneously (1).

In apes, however, dorsiflexion in the midfoot

ensures that the heel leaves the substrate before

the midfoot, a condition known as a “midtarsal

break,†which can be up to 28° in magnitude (28).

This dorsiflexion occurs primarily at the cuboidmetatarsal

joints (10, 26, 29) and is distinct from

the medial collapse in some human feet, which is

far less pronounced and occurs to a variable degree

at multiple joints (7, 11, 12). The transverse and

longitudinal pedal arches and metatarsophalangeal

dorsiflexion inferred fromAL 333-160 signal an

osteological pattern of midfoot stability and lateral

foot rigidity unknown in the apes.

Dorsoplantar curvature of the lateral tarsometatarsal

joint surfaces contributes to the distinctive

midtarsal dorsiflexion in great apes

(8, 10, 26, 29). These surfaces on the human

proximal fourth and fifth metatarsals are flatter.

The proximal articular surface of AL 333-160 is

nearly flat (Fig. 4B), matching the mean of the

modern human sample. Limited dorsiflexion at

the lateral tarsometatarsal joints (10, 30), which

would contribute to a relatively stiff lateral foot

like that of modern humans, can be inferred for

A. afarensis. AL 333-160 also has dorsoplantarly

deep metatarsal bases, a condition also described

for Ardipithecus ramidus (25) (Fig. 4B). This

would limit dorsiflexion and plantarflexion at the

lateral tarsometatarsal joints, additional evidence

of a human-like relatively stiff lateral foot fundamentally

different from that seen in apes.

A rigid lateral foot in A. afarensis is further

suggested by the orientation of the facet for the

lateral cuneiform on the base of the AL 333-160

fourth metatarsal (Fig. 4C), mirroring the complementary

facet seen on the lateral cuneiform

(14, 19). In A. afarensis, as in modern humans,

H. habilis [OH 8 (31)], and the Dmanisi H. erectus

feet (24), the lateral cuneiform is elongated, extending

distally past the cuboid, so that it articulates

with the proximomedial corner of the fourth

metatarsal at an obliquely oriented facet (14, 19).

In apes, the lateral tarsometatarsal joints are aligned

in the same coronal plane in such a way that the

distal end of the lateral cuneiform is coplanar with

the fourth tarsometatarsal joint, and the oblique

facet on the fourth metatarsal for the lateral cuneiform

is absent (Fig. 4C), a configuration that

facilitates dorsiflexion at the tarsometatarsal joints

(10). Thus, even if there wasmore calcaneocuboid

mobility in A. afarensis than in modern humans

(32, 33), this was evidently not the case for the

lateral tarsometatarsal joints [see also (34)].

I'd say that goes beyond a basic high school anatomy course, Bob.

Here is a direct contradiction to Meldrum's paper:

Most researchers conclude that the 3.6-

million-year-old footprints in the Upper Laetolil

Beds at Laetoli, Tanzania, evince a medial longitudinal

arch [for example, (35, but see (36)]. Although

A. afarensis is the only hominin species

represented by fossil remains in these beds at

Laetoli, one objection to this species having made

the prints is the purported absence of the medial longitudinal arch in the Hadar foot (35, 37). The

morphology of the AL 333-160 Hadar fourth

metatarsal eliminates that objection.

To respond to a few points brought up in this thread, the midtarsal break is not considered a "Super-arch" or a high arch, just the opposite. The midtarsal break is what apes have instead of an arch, the midfoot is flexible so that they can grasp branches. Some time in our evolution we developed an arch which was advantageous for long distance running and walking. At some point hominin lost the midtarsal break. The authors of this paper conclude that afarensis did not have a midtarsal break.

What does this have to do with sasquatch? One problem is the challenge of proposing that a bipedal terrestrial ape like sasquatch has a midtarsal break, when so far we keep seeing bipedal apes with no midtarsal breaks. It's contentious, how much energy is wasted by having one, and for the most part, it's useful for being in the trees, not much on the ground.

[wolftrax]

Another point of interest. There is one person who keeps claiming that casting artifacts tests are not realistic because volcanic ash is not found in natural substrates because it washes away within a short amount of time. The Laetoli tracks were made in a layer of volcanic ash that is still intact after 3.6 million years.

As a matter of fact, we use fossilized volcanic ash to date fossils using Potassium/Argon dating, like for this dinosaur fossil Eodromaeus murphi, dated at 230-million years old. Ash can stick around for a very long time.

http://www.livescience.com/9291-dinosaur-graveyard-reveals-oldest-rex-relative.html

Edited March 1, 2011 by wolftrax

[BobZenor]

some excerpts from the paper:

...

I'd say that goes beyond a basic high school anatomy course, Bob.

...

It is more a comprehension thing. I said biology, not anatomy. It was the basic understanding of evolutionary biology and basic mechanics that I questioned. It was about the basic premise of an arch being required for bipedalism as is implied by the association with the alleged arch proving that it was no longer a tree climber. It is what Germans would call Fachidiot or someone that doesn't see the big picture because they become so narrowly fixated on a single field. The entire premise of it having anything to do with it climbing trees is nonsense. A foot without an arch can obviously function fine. Human feet evolved to be smaller and rely on arches because of that. Assuming that our problems with flat feet extends to something before those evolutionary changes associated with our arch is ridiculous. It is also ridiculous to assume that something living partially in trees couldn't form an arch.

[wolftrax]

The paper doesn't argue that afarensis didn't at least spend some of the time in the trees, but it does contend that it spent more time on the ground and was more adapted to ground dwelling then tree dwelling. The midtarsal break is an arboreal feature, the arch developed some time in our evolutionary timeline and aided us in long distance running and walking.

However, I thought you had contentions about afarensis having an arch. But since you weren't talking about anatomy, then I guess it doesn't matter.

Edited March 1, 2011 by wolftrax

[Guest]

A foot without an arch can obviously function fine.

<for climbing trees>

Yes, some of us with high arches can also climb trees just fine, but if there's something "better" than "fine", then it's the better thing that will be perpetuated through natural selection. This is why creatures that rely on sustained running over hard ground tend to have elongated limbs with stiffened feet and those that are primarily arboreal tend to have feet that can grasp limbs.

[BobZenor]

<for climbing trees>

Yes, some of us with high arches can also climb trees just fine, but if there's something "better" than "fine", then it's the better thing that will be perpetuated through natural selection. This is why creatures that rely on sustained running over hard ground tend to have elongated limbs with stiffened feet and those that are primarily arboreal tend to have feet that can grasp limbs.

I wouldn't have had any problem at all with that interpretation. You used the words "tend to".

Linked article

The discovery of a new hominid skeleton in Ethiopia shows that the human ancestor represented by the famed "Lucy" walked on two legs rather than moving like a knuckle dragger, researchers say.

Anthropologists have long debated whether the short-statured female Lucy typically walked upright or not. She had represented the only known skeleton of Australopithecus afarensis, and would have stood at a height of 3.5 feet (about a meter) some 3.2 million years ago.

But the second partial skeleton, named "Kadanuumuu" ("big man" in the Afar language), has both the shoulders and long legs that compare well to modern humans, according to Yohannes Haile-Selassie, curator and head of physical anthropology at the Cleveland Museum of Natural History in Ohio.

"It's only the second partial skeleton of A. afarensis to be recovered; it's 400,000 years older than Lucy and it's male," Haile-Selassie said. "But just as important, the fossil remains provide conclusive proof that A. afarensis could walk upright freely without the use of its hands."...

The single lateral metatarsal bone somehow proved that? It should have already been largely established by Lucy's pelvis, legs and arms. Even if you somehow deduce a humanlike arch from a single bone on the outside of the foot, it doesn't translate into proof by itself.

We lack an arch on the outside of the foot. How is the foot ridgid on the outside without an arch? If you curved that bone, it could still be flat on the bottom of the foot. That is just to point out that arch part being discussed is on the inside of the foot and that isn't the bone he was talking about. It is meaningless besides trying to establish afarensis as an ancestor and Salassie likely has a stake in that being so.

The fact of the matter is that a flat foot could function fine so calling that proof of anything even if it were somehow true is what I was complaining about. The feet are stiffened into the arch by tendons and they don't show up in fossils besides grove marks sometimes. There is no reason to assume that a humanlike arch is required for stiffening the foot. I am not arguing your point. It was the idea from Salassie that a single bone proves it wasn't a "knuckle dragger" whatever that is supposed to be. It obviously isn't a chimp. It has been walking upright since Ardipithecus. Its foot is obviously significantly different than a chimps and it is obviously more bipedal though I don't accept the outside metatarsal as absolute proof of that.

There are other ways as well to store energy than by that arch but that is another argument. I don't accept their theory because they are probably biased, make nonsense statements about absolute proof, it is somewhat contradicted by the floresiensis flat feet, the bone isn't even part of the arch.... I also just don't think they can tell if a foot is even flat from that bone.

Edited March 1, 2011 by BobZenor