Footnote: Evolution Adds Nothing
A new study of foot stiffness helps explain human walking and running, and might inspire robots. Evolution adds nothing.
The stiffness of the human foot is designed for upright walking. The feet of lower primates, by contrast, is flexible in the center of the sole, so that they can climb trees and grasp limbs with their feet.
The human foot is stiff but not flat. Two arches, roughly perpendicular to one another, add spring to our steps. The longitudinal arch, running from heel to toe, supports the ligaments that absorb shock and maintain foot shape. The transverse arch, running cross the foot, has been largely ignored by physiologists seeking to explain foot stiffness, thinking that the longitudinal arch provided most of it. A new study shows, however, that up to 40% of the foot’s stiffness is provided by the transverse arch. This makes sense in retrospect, if you consider how a card or currency bill stiffens when curled, notes Madhusudhan Venkadesan of Yale University and his colleagues in a paper published today (26 Feb 2020) in Nature, “Stiffness of the human foot and evolution of the transverse arch.”
The stiff human foot enables an efficient push-off when walking or running…. The uniquely arched morphology of the human midfoot is thought to stiffen it, whereas other primates have flat feet that bend severely in the midfoot. However, the relationship between midfoot geometry and stiffness remains debated in foot biomechanics, podiatry and palaeontology. These debates centre on the medial longitudinal arch and have not considered whether stiffness is affected by the second, transverse tarsal arch of the human foot. Here we show that the transverse tarsal arch, acting through the inter-metatarsal tissues, is responsible for more than 40% of the longitudinal stiffness of the foot. The underlying principle resembles a floppy currency note that stiffens considerably when it curls transversally.
Gege Li at New Scientist titled her article, “We have only just figured out how human feet work.” She quotes Harvard foot physiologist Daniel Lieberman calling this finding a “game changer.” He comments, “It helps explain why and how people with flat feet are able to walk just fine, and how our ancestors were able to walk for millions of years before the longitudinal arch evolved.”
Wait a minute. Evolved?
Lieberman just conjoined two unrelated statements: “why and how people with flat feet are able to walk just fine” – a statement of physiology, and “how our ancestors were able to walk for millions of years before the longitudinal arch evolved” – a Darwinian story.
Once again, Chuck Darwin’s hoary face just popped out of the Joker box, interrupting a scientific observation about a well-designed mechanism in human feet that allows us to run, jump, walk, stand, tiptoe, pirouette, lift weights, land from a height, and do a thousand other intricate movements over a lifetime, with only rare problems. Some centenarians are still walking after 100 years! Feet exceed the design specifications of almost any man-made machine. What’s evolution got to do with it? Who turned the crank? Or what crank turned the science into story time?
Darwinians seem to have some deep inner need to look into deep time in their crystal balls, trying to see how this or that marvel of engineering “evolved” over millions of years.
A press release from the University of Warwick, where some of the scientists hail from, begins all right: “Mathematician identifies new tricks for the old arch in our foot.” Whether it is old or not might be off mark, but experiments on the stiffness of the transverse arch confirm the scientific findings. Why bring up evolution? When they do, the perhapsimaybecouldness index rises and the fogma thickens.
“Our evidence suggests that a human-like transverse arch may have evolved over 3.5 million years ago, a whole 1.5 million years before the emergence of the genus Homo and was a key step in the evolution of modern humans,” explains Prof. Venkadesan. It also provides a hypothesis for how Australopithecus afarensis, the same species as the fossil Lucy, thought to not possess longitudinally arched feet, could generate footprints like humans that were discovered in Laetoli.
Hold it! Is that what the science says?
The Laetoli footprints look like they were made by modern humans. The only reason they are attributed to Lucy the Ape from Afar (Australopithecus afarensis) is that the dating method they used resulted in a date far earlier than the evolutionary scenario would allow for modern humans to have lived then. It’s not like they have settled science to determine anything reliable. They admit,
Furthermore, there are also debates over when a stiff midfoot arose in human evolution, including what kind of foot made the 3.66-million-year-old partly human-like footprints at Laetoli.
In the Nature paper, the scientists compared the arches in the foot bones of fossil apes and humans, at least “hominins” classified in the genus Homo, such as Homo naledi, Homo habilis, and Homo erectus. Each of these, the scientists concur, had prominent transverse arches like modern humans have, so no evolution is evident. Moreover, they cheated by using interpolation!
Among the fossil feet, all except the foot of H. naledi were incomplete in some regard. For those incomplete feet, an extant species was selected as a template by taking into consideration published analyses of other postcranial and cranial elements. On the basis of this information, H. sapiens was chosen as the template for H. erectus (Dmanisi) and H. habilis (Olduvai hominin) and G. gorilla was chosen as the template for A. afarensis (AL 333) and the unknown hominin foot found in Burtele.
Even if the cheating were to be tolerated as acceptable inference, the foot bones of all the members of Homo cluster together with similar arches. Their illustration (Figure 4) shows a big, wide gap between apes and the first member of Homo they examined. But they put Lucy’s foot just to the left of Homo habilis. Why would they do such a thing?
All members of Homo are members of the human family, and separate from apes, according to Rupe and Sanford in their book Contested Bones (2nd ed., 2019). They quote paleoanthropologists all agreeing that the Laetoli footprints, when first discovered, were “undoubted human footprints” and were “remarkably similar to those of modern man” (pp. 137-139). They had arches and toes and heels. One said they were “indistiguishable from those of modern humans.” Another said they looked like footprints you would find today at the beach. So on what basis did they attribute the Laetoli prints to Australopithecus afarensis (a.k.a. Lucy)? The fossil foot bones were incomplete or missing. The only reason they did it, Rupe and Sanford explain, was because of evolutionary preconceptions. The prints were too “early” for Homo.
Nature‘s “News and Views” summary used the e-word evolution 14 times, in spite of the fact that, as explained above, there is a big gap in the fossil evidence. They offer no scientific, observational evidence to fill in the gap. They present no mutations that would have been selected to gradually change the shape of an ape foot into a bipedal human foot with arches, stiffened for walking. Their B.A.D. presentation amounts to deceitfulness, motivated by their philosophical attachment to Darwinism. As usual, the gutless, uncritical DODO media swallowed the tale and ran with it. “Overlooked arch in the foot is key to its evolution and function,” trumpeted Phys.org, using the e-word 12 times. “Such stiff feet—unique to humans among primates—were important for the evolution of bipedalism,” the article says. But there was no evidence for evolution in the paper! The stiff foot is evidence for human exceptionalism! The only worthwhile conclusions involve intelligent design —
It is conceivable that new treatments that take advantage of transverse-arch curvature to modulate foot stiffness could be developed for various foot disorders. Perhaps even more exciting are the implications of this work for efforts to mimic a human foot when designing prosthetic limbs or legged robots.
Readers need to stuff Chuck back in his Joker box and look at the design evidence. It’s not just foot bones that need to support upright walking; there are muscles, joints, tendons, ligaments, nerves, blood vessels, muscles and a host of other supporting structures required. A recent paper in PNAS by Farris et al., “The functional importance of human foot muscles for bipedal locomotion,” talks about some of these design requirements. They even compare the plantar fascia, which runs from the heel to the toes, as a “windlass mechanism” that allows the foot to push off and gain traction:
This “windlass” mechanism proposes that winding of the plantar aponeurosis around the metatarsal heads during late stance raises the LA [longitudinal arch], and passively stiffens the foot for propulsion (Fig. 1). As such, the plantar aponeurosis has often been considered the most important soft tissue in supporting the LA.
Not only that, the ligament is supported by “plantar intrinsic muscles of the foot (PIMs)” that run across the ligament, this paper finds, adding another layer of complexity to the ‘simple’ act of upright walking. Is this a product a blind mutations selected gradually in some ape?
In short, evolution contributed nothing of any scientific substance to the findings about human feet, and how transverse arches stiffen the feet for upright walking. The forays into evolutionary storytelling serve no purpose other than to perpetuate the worldview beliefs of the storytellers, against the actual evidence for exquisite design in the human foot. The storytelling, as a consequence, then serves to deceive the public into accepting a myth that evolution is true and useful, and that the findings help us “understand” a little more about the “evolution of upright walking.”
We must keep up these exposés of evolutionary propaganda, until Darwinism becomes a footnote in the history of discarded myths.