Things exist either because they have

recently come into existence or because
they have qualities that made them
unlikely to be destroyed in the past.

Richard Dawkins1

I like old things. Most of my furniture is inherited. So are many of my books and even a surprising number of my pieces of clothing. I also like old structures in the human body. I am increasingly convinced that the evolutionary age of a biological component is a sign of its reliability. Newer anatomical equipment is less tried and true – more apt to break down. Old stuff survives because it works.

But what has this to do with Rolfing® Structural Integration (SI)?

Well, old structures often survive because they can be repurposed. Old things can serve new ends. Also, and more relevant to the diversity of movement patterns, old things can serve multiple ends. In few animals is this as true as in Homo sapiens. Biomechanically, we humans specialize in not specializing. Using the same structure in different ways is essential to our adaptability.

What is the best example of this? The reader may be skeptical when I claim that, of all of the different structures, the foot is the best example of adaptive ingenuity. I will make this case, and support it with evidence, but who knows? This is not a rhetorical question: I honestly invite every reader to present a similar case for your favorite body part. (The diaphragm, anyone?) The modern human foot is a lot older than the modern human hand, the pelvis, the spine, or the rib cage, etc. The foot is certainly far older than that cranky and bug-ridden piece of new technology that we call our brain. Anyone who wishes to celebrate a structure other than the foot as the pinnacle of evolutionary intelligence would be hard-pressed to find one with such a perfect balance of ancient stability and timely adaptability.

The Pioneer Foot

In my earlier article, “The Three- Dimensional Animal: Changing Views of Bipedalism and Its Limitations” (Boblett 2015), I speculated (unwisely) about the age of Homo naledi. Like far more qualified people, I considered this animal a likely early member of our genus, an intermediate species in the transition from arboreal to terrestrial life. I presumed that Homo naledi was genetic to the entire Homo lineage. Homo naledi is now known, however, to be only 335,000 to 235,000 years old. The youth of this species is, therefore, proof of how recently our seemingly monolithic genus maintained a remarkable diversity of movement patterns – but with strikingly similar feet.

Mind you, the Homo naledi foot probably differed from your foot in several important ways. For instance, the former was evidently more robust than that of modern Homo sapiens, and it would have furthermore borne slightly curved phalanges for climbing. But one writer on Homo naledi, Andrew Howley (2015) at National Geographic® Magazine, points out that naledi’s foot structure is well within the variation found in Homo sapiens, if you include Khoi-San people: “If you found just this foot, you’d think it belonged to a bushman.” (As I have written before, anthropologists in Africa pray fiercely for a skull to go with other human fossils, since otherwise the anatomical details of this species remain uncertain.)

So, in this apparent outlier to human evolution, I am still struck by the juxtaposition of ‘primitive’ and ‘advanced’ traits. On the one hand, Homo naledi had remarkably modern feet. On the other hand (pun intended), its hands were beyond human range in their adaptation to climbing. Naledi also had a round, ape-like waistline incapable of our own rotational independence of rib cage and ilia. So I repeat my assertion that this odd combination of stable and derived traits points to the availability of the human foot to support a great variety of movement patterns.

In this new article, I go back even further. In my previous essay, I went back beyond Homo naledi to speculate a bit about the transition from monkey to ape. Now I go to the emergence of monkey-like traits – mostly in the foot. This occurs in Archicebus achilles, a tiny primate from 55 million years ago that lived in China during the early Eocene. This creature weighed twenty to thirty grams (i.e., about one ounce). It was smaller than most mouse lemurs, which are today’s smallest primates. On the phylogenetic tree, Archicebus achilles lies near the juncture between nocturnal tarsiers and the diurnal anthropoids. The latter include monkeys, apes in general, and the particular bipedal ape who’s writing this very article.

Archicebus is not the oldest primate fossil. But it is by far the oldest primate fossil with anything like its level of completeness. This complete skeleton allows me to repeat my motto: “The foot often evolves first; other body parts catch up.” Then the foot retains its initially modern form as the rest of the body (to employ a teleological perspective) ‘catches up’.

As with Homo naledi, the foot of Archicebus emerges as a surprisingly modern structure in juxtaposition with less evolved traits:

Archicebus differs radically from any other primate, living or fossil, known to science. It looks like an odd hybrid with the feet of a small monkey, the arms, legs, and teeth of a very primitive primate, and a primitive skull bearing surprisingly small eyes (Ni et al. 2013).

I compare this with my previous article’s description of Homo naledi, in which I quoted William Harcourt-Smith of the Paleontology Department of the American Museum of Natural History (2015) saying that “Quite obviously, having a very human-life foot was an advantage to this creature because it was the foot that lost its primitive, or ape-like, features first.”

In these two cases, the relative modernity of the foot differs, because it supports two different breakthroughs in primate development. Archicebus displays the beginning of precisely the ‘ape-like’, or in fact monkey-like, grasping foot that then ‘de-apes’ by narrowing and stabilizing in Homo naledi. But in both transitions, the relevance for Homo sapiens is the survival through all three species of repurposed old structures: our long calcanei and long metatarsals.

Why Metatarsals?

Why then do I focus on the metatarsals instead of calcanei? After all, the species I use as an example of old-and-new in juxtaposition was named “achilles” after the character from The Iliad whose heel was famously vulnerable – a clear reference to Archicebus’ strikingly modern calcaneus.

I choose metatarsals for two reasons.

First, our long primate metatarsals are even older than our elongated calcanei. Simply put, our primate habit of grasping is even older than our tarsier- or monkey-like habit of leaping. (I put the supporting argument for this in an endnote2 because it slows down the flow of an already-dense argument.) Briefly, primates even older than Archicebus display long metatarsals without its specific calcaneal leaping adaptation. But the remains of these older primate skeletons are so fragmentary that they do not fit into my narrative of feet retaining strikingly similar features over time to support radically changing bodies.

Second, I am more interested in grasping (and the movements that evolve out of grasping) than in leaping. Yes, leaping is deeply incorporated into our repertoire of available movements. This happens in several ways, mostly through the incorporation of leaping into bipedal gait, especially in running. But my focus here is on the possibility of evoking, in Rolf Movement™ work, what I will stipulatively call ‘the generous foot’ or ‘the generous sole’. More ‘handy’ even than leaping for the evolutionary fitness of Homo sapiens is grasping. And as we shall see, the child of grasping is giving.

As I turn to the repurposing of the act of grasping, I must describe the ecological context of Archicebus and its descendants. I must now sound rather like a high school biology teacher, so I invite you to skip this next section if it repeats stuff you already know.

The Fruits of Perception

Terrence McKenna once remarked that “Animals are something invented by plants to move seeds around.” On this planet, plants call the shots. That’s not news to me. I try humbly to know my place as a mere vertebrate and act accordingly. But even I was surprised, when I first learned of it, just how deeply and directly the needs of plants manipulated our early primate evolution.

Fifty-five million years ago, the Earth that supported Archicebus was still coming to terms with one of its greatest extinction events, the KT Event a mere ten or eleven millions years earlier. The web of life was still vibrating. Seventy-five percent of all species had died out. But the Manhattan-sized asteroid that hit our planet, apparently preceded by some fierce volcanic activity, introduced new problems . . . and opportunities.

As usual, the plants were quick to respond, giving animals new opportunities. Call it a ‘job-creation program’. The problem was an old one: how to deliver packages of DNA? For tens of millions of years, angiosperms had excelled at bribing various DNA-carrying critters with pollen and relatively small fruits. Flowering plants, which by definition are also fruiting plants whether or not we humans eat the fruit, had done a good job of taking over a lot of land and a lot of light from their drab gymnosperm competitors. But most of the pollinators, which tend to be specific to the plants they serve, had gone extinct. Once again, land and light were up for grabs. First come, first served.

To address this, some plants made their fruits especially big and attractive. Highly specialized pollination was still useful for some flowering plants, but the free-for-all competition for these big new goodies was an advantage in a world where everything was changing rapidly. In the fierce scramble, birds predominated. (That’s when they weren’t trying to become the top predators in the new ecosystem, which they nearly succeeded in accomplishing.) After all, birds had one advantage denied to mammals: they could see color. They quickly developed the ability to discern when these new fruits were at their ripest. Mammals, by contrast, had lost color-vision. Even before dinosaurs took over, our remote ancestors had carved out a nocturnal niche. The long night took its toll. But Archicebus, with its small eyes, was already emerging into the light. We don’t actually know whether Archicebus saw in color. We only know that most of its descendants can do this, almost uniquely for mammals. (Some marsupials see in color.)

With its large canines and the sharp crests on its premolars, Archicebus was still a bug-cruncher. Actual fruit-eating probably can be detected in the genus Apidium a mere 30 million years ago, with its more derived dentition, its narrower phalanges, and its replacement of claws with fingernails and toenails. But the increased flexibility permitted by the long metatarsals of Archicebus was certainly a useful preadaptation for the further specialization of its descendants (or great-times-millions nieces or nephews) in fruit-eating. Although not everybody accepts the fruit-color-vision theory of primate evolution, it remains a dominant explanation for the evidence from the fossil record.

Again, what has this to do with Rolfing SI? Well, it led to a newer shift anterior to the metatarsals, which leads to our own narrow and sensitive fingertips – and toe-tips. Now I’m going way out on a limb. Wanna join me?

The role of fruit in primate evolution is often traced in our large brains and our complex social networks. I consider the latter as more basic, since so much of our cortical space as primates is taken up with social relations. But the brain is not the only organ that supports – and is shaped by – our increasingly large and complicated groups. I hope that I tickled you before with the idea that ‘the child of grasping is giving’. I believe that grasping and giving are linked in the social organization at the root of pre-lithic specialization of hands. By this I mean that long before our ancestors used their hands to make an increasingly complex array of stone tools, they used them for the far more basic tasks of carrying food or babies, as well as picking ripe fruit without wrecking it so badly that we couldn’t give it to others. In other words, we switched from catching things with our claws to an increased sensory awareness through our nailed digits. The two processes – sensing and serving – evolved in tandem. Likewise, hands and feet seem to diverge in Homo sapiens, but in fact their separate specializations support and, to put it in an open-ended way, ‘enlighten’ each other.

Palms and Soles: The Dance of Opposites

Down the road toward us, the specialization of the human hand goes in one direction, and the specialization of the human foot seems to go in the opposite direction. But, paradoxically, these two seemingly opposite developments at opposing ends of the appendicular complex contribute (or have the potential to contribute) to mutual learning. How many of us use hand or wrist exercises to foster coronal awareness down below? How many of us have noticed that increased freedom in toes, arches, and ankles can lead to unexpected changes in limitations on hands and wrists? All I have added here is a bit of time-depth, a bit of context.

Now I will go further. I want to add an aspect that is not only biomechanical or even perceptual, but what I might call ‘interpersonal’ – if among ‘persons’ we include things not always human but certainly in relationship with us. We exist within a web. To negotiate that web consciously is to negotiate our own proprioceptive web mindfully.

In another article in this issue (Boblett 2018; see page 19), “The Three-Dimensional Foot, Part 3: Opening the Generous Sole,” I pursue specific ways of waking up a foot so that it senses, receives, and gives. You might call that other article the prose of waking up the foot, while this article is written in something more like poetry. Here’s the poetic version. In running or, indeed, in mindful walking – in negotiating the literal give-and-take of moving over tough terrain – the foot must learn not only to grasp, but also to give. This act of giving, of offering, may be hard to differentiate from the also-important act of pushing-off, which is really a throwing-back of collected gravity. But if we merely grasp-and-throw in our stride, we miss the relaxation aspect that must underlie intelligent, information-rich grasping, which can be a form of accepting. The shock of a log or a boulder meeting the sole of the foot is better met lightly than tightly. This collected-and-stored gravity (and knowledge) can thereby be gathered softly, gracefully, gratefully, the force radiating with equal gratitude up into the whole rest of the balancing system.

For one thing, this goes back to what I have written before: that the primary function of toes is not biomechanical, but sensory. They are our antennae, designed to prepare the ‘eye of the foot’ itself to be a perceiver more than an actor. But there is still a biomechanical component to all this: relaxation, which is simply eccentric rather than concentric movement of muscles. In a sense, the ‘pupil’ of the foot’s ‘eye’ dilates to receive force and information at the same time . . . provided that force and perception are differentiated with sufficient nuance.

From catching to caressing, from merely grasping to what Ed Maupin has called “the curious touch,” the foot and the hand both express two aspects or rather stages of one seamless act. Our hands and feet express something deeply rooted in how we relate to each other as social primates and to an ever-widening network of other partners in the world of movement.

Again, what has this to do with us? What has this to do with easing the path of the pregnant mother, the polio survivor, the running addict? Sometimes the larger context is more helpful than the specific symptom or its easing. I hope I have provided that here. If I’ve been too vague and you’re hoping for something more specific, that’s what my other article (page 19) is about. If I’ve simply lost you on this journey, I hope you’ve wandered somewhere useful and beautiful. I thank you for your time. I welcome your ideas.

Michael Boblett works in San Diego, California. He has been a Certified Rolfer since 2003 and a Certified Advanced Rolfer since 2008. Michael is a retired Unitarian minister. His

advanced degrees (MA, MDiv, and DMin) are from Pacific School of Religion in Berkeley, California. At seminary, he focused on the anthropology of religion, with experiential training under Michael Harner, author of The Way of the Shaman. Michael runs marathons and hikes up mountains wearing Vibram® Five Fingers. His website is www.rolfer.biz.

Endnotes

1. From The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design, by Richard Dawkins. New York: W.W. Norton and Company, 1986.
2. According to Moyà-Solà et al. (2012), “this analysis reveals that primates as a group display a relatively longer distal calcaneus, relative to both total calcaneal length and body mass, when compared with other mammals. Contrary to current expectations, morphofunctional analysis indicates that a moderate degree of calcaneal elongation is not an adaptation to leaping, but merely a compensatory mechanism to recover the lost load arm (metatarsal length) when the foot adopts a grasping function in order to maintain locomotor efficiency. Leaping can be inferred only when anterior calcaneal length departs from the scaling of non-specialized primate groups.” In other words, the calcaneus of Archicebus achilles displays not only the distal but also anterior elongation consistent with leaping, thereby setting Archicebus apart from even more primitive Paleogene primates like Anchomomys, which even then showed a calcaneal adaptation to the grasping motion allowed by elongated metatarsals. The reason I don’t use Anchomomys for this article is because that species only shows in fragmented remains, thereby not giving me the interesting pattern of juxtaposed ‘primitive’ and ‘evolved’ traits that I find useful in making my case about feet.

Bibliography

Boblett, M. 2018 Mar. “The Three- Dimensional Foot, Part 3: Opening the Generous Sole.” Structural Integration: The Journal of the Rolf Institute® 46(1):19-22.

Boblett, M. 2015 Nov. “The Three- Dimensional Animal: Changing Views of Bipedalism and Its Limitations.” Structural Integration: The Journal of the Rolf Institute® 43(3):28-31.

Howley, A. 2015. “Homo naledi’s Nike Ready Foot.” National Geographic’s “Changing Planet” blog, September 16, 2015. Available at https://blog.nationalgeographic. org/2015/09/16/homo-naledis-nike-ready-foot/ (retrieved 2/20/2018).

American Museum of Natural History 2015. “Foot fossils of human relative illustrate evolutionary ‘messiness’ of bipedal walking: Study of Homo naledi suggests that new species walked upright and also climbed trees.” ScienceDaily® 10/6/ 2015. www.sciencedaily.com/ releases/2015/10/151006131938.htm (retrieved 2/18/2017).

Moyà-Solà, S., M. Köhler, D. Alba, and I. Roig 2012 Jan. “Calcaneal proportions in primates and locomotor inferences in Anchomomys and other Paleogene Euprimates.” Swiss Journal of Paleontology 131(1):147-159.

Ni, X. et al. 2013. “The Oldest Known Primate Skeleton and Early Haplorhine Evolution.” Nature 498:60-64 (5 June, 2013). Available at www.nature.com/articles/ nature12200 (retrieved 2/20/2018).The Three-Dimensional Animal, Part 2[:]