Evolution, Tolerance, Humaness and Humaneness

As our brain expanded in evolution, we became more and more adaptable. Social structure became more complex, cultural and symbolic phenomena began and refined communication became possible.

Contemplation We developed many types of adaptability: physical, spiritual, cultural and emotional adaptability are among the hallmarks of human evolution. To say that we have evolved to run in one way, and that way must be that we should always land on our forefoot in shoes dictated by any authority is absurd. But the discussion that has taken place in the past few years demonstrates the impact of culture and society on thought and how memes are generated and circulate in traditional and new media.

To say that evolution has mandated that we are designed to wear no shoes or minimal shoes would have precluded our explorations of much of our own planet, let alone our exploration of the moon’s surface. And the movie Gravity just wouldn’t look right with Sandra Bullock wearing a white suit with no shoes while floating around in space.

Have our minds evolved faster than our bodies? Does peer pressure play a major role in our social development? Are we justified in wearing shoes in hostile environments or during particular sports activity? Or should we all take feet as a special evolutionary case in that they are meant to be set free from the encumbrance of all shoes?

Do some intelligent people cherry pick literature for one reason or another and are they knowingly intellectually dishonest? It is possible that some may not even be totally aware of what and why they are taking a particular approach on this topic. A recent study reported in Nature demonstrated that social ideas on climate change are influenced at the subconscious level by those around you. The media can have a tremendous impact. The trend in which the new needs to be continuously highlighted (and yes the new is often good, but not everything new is going to work well or last long – or we wouldn’t need to see so many new shoes every year. ) to the point where what has recently been new and highly touted is suddenly set upon and put down.

Should someone not agreeing with our particular choice engender hate, disrespect and a virtual piling on? That seems to perhaps be a hallmark of humanness but not humaneness. Historically and culturally we often seek the similar and the like and avoid or abhor the different. When cultures merge and converge though, some of the differences no longer matter. Often, those outside of the mainstream or lagging behind the trend line are disparaged. Sometimes quite strongly disparaged. It is clear in politics and global affairs that unfortunately this often guides our approach to life and society.

For the runners among us, I’ve emphasized that we are all runners. That is our commonality and what should bond us together. Politics, shoes, feet, none of that really matters and there is room for all kinds of runners among the running community. There are sprinters, milers, marathoners and ultra-marathoners. There are barefoot runners, minimalist shoe runners, runners in structured cushioned shoes, runners in neutral shoes, and runners who run comfortably in motion control shoes ( a few anyway, but not a good choice for most people). We all run or if we are injured or otherwise unable to run, we all think about running. My belief about shoes is that you should run in what is comfortable and works for you. A recent book on evolution and running insists, in spite of an absence of evidence that comfort is a bad indicator of success. However Benno Nigg and others have done research that indicated that comfort was a relatively good predictor of fewer injuries among military recruits. With all of the research that has been done we still have essentially no studies that tell us how to avoid running injuries. One budding guru said on a national television program “throw away your high tech running shoes and you will never have another running injury”. Unfortunately, that was patently false and misleading. There are a number of new studies showing injury trends with different shoes – the first study which comes to mind is one that concluded a recommendation to wear a motion control shoe just based on a low arch foot type does not work well and seems to lead to more injuries than the choice of another shoe type.

George Sheehan said that “we are all an experiment of one.” We do have to discover what works well for us as individuals and follow that path. There is much to read on the Internet that can be helpful, but the correct answer for one individual may be hard to find. Sometimes guidance and the advice of a professional is helpful when one of us becomes injured, or has repeated injuries.

One thing is certain: everything goes better with exercise. We all are built to move. In fact evolution has led us to be in dire need of movement and evolution.

So now that we have arrived at another end of year holiday season, it is a good time for both reflection and movement. Plan your approach to the next year of exercise. Work on tolerance – improve your tolerance to endurance exercise, strength training and speed workouts. Improve your tolerance to your fellow runners and human beings. Work on being humane in addition to being human.That you’ll find is the hardest type of tolerance to develop.

But that animal in us does need exercise even during the holidays. How else will you work off those large meals and party foods and drinks?

Walk This Way

Science magazine has just published an article on the oldest footprints found which correspond to modern day human biomechanical function. These footprints are about 1.5 Million years old and appear to belong to homo erectus, a species which predated homo sapiens.Old Foot Prints

The great toe was in similar alignment to modern day humans. An arch was present. Heel strike occurred at initial contact, weight transfer progressed forward with apparent foot function in the midfoot (midtarsal joint) proceeding in a modern manner. Weight bearing then went to the central metatarsals, (seemingly bearing more than the first metatarsal) followed by push off at the big toe.

The foot prints appear to show someone slowed to a near stop (or starting from a stop) and then picking up speed. To my eye, with an initial angle of gait being first high on the left, than on the right (about 24-26 degrees), followed by a narrow angle of gait (about 1 degree) as speed picked up, it looked as though the pre-human hominid was looking to the left, and then to the right. He likely would have been able to cross some of our streets, at least those with traffic bearing to the right side of the road. And in fact he may have avoided getting run over by a bovine, which blotted out part of one of his foot prints.

Bipedalism, walking on two limbs, was an important evolutionary step. Bipedalism is thought to have been present for about 6 million years.  It is energy efficient. It allows free hands to carry things, make tools, build things that are more complex than bird’s nests and beaver’s dams. It frees the hands  for hunting and fishing. Ultimately, it led to holding hands while walking. It led to artistic undertaking such as cave paintings, fashioning musical instruments, fingering the holes of a flute or playing chords and notes on strings. But, it also led some to throw stones at others. But that is another story.

The energy saved may have led to enhanced brain function. The energetics of bipedal walking, determined on an individual basis (some calculations have been done on chimpanzees) show a significant reduction in energy cost for walking in a bipedal manner. Some theorists believe that upright walking, and even running came before the larger skull and brain size.  That may very well have been true, based on these and other findings. There are many interesting adaptations and changes that occurred over the years. Some of the differences that occurred evolutionarily that are important to human bipedalism and are of significant, walking and running energetics include altered f0rm and function of the calf muscle, Achilles tendon, and the gluteal muscles. But, we can’t judge all of that from the footprints alone.

Science 323, 1197 (2009);  Early Hominin Foot Morphology Based on 1.5-Million-Year-Old Footprints from Ileret, Kenya. Matthew R. Bennett, et. al.

Science Now “Early Humans Toed The Line”


Achilles Tendon: The Missing Link? (repost 2007)

Getting Your Avatar Moving Better Than a Monkey

Dr. Bill Sellers of the University of Manchester has just announced that he has made a computer model that demonstrates that tendons are an important structure to store and return energy. Well, this may be big news for my 70 Priest in World of Warcraft, who soon may be modeled to have a bit more spring in his step. Already, my undead priest is able to walk and dance better than the gnomes can, but he is hardly able to run. Now, what does the announcement mean to the rest of us and what did Dr. Bill say about his computer modeling?

“What we’ve found is that muscles are attached to bones by tendons at the end and these tendons are big springs that store energy. If we make a model without tendons, it turns out that it’s rubbish.” Unfortunately a view of the model indicates that it seems to resemble what I imagine his recent model of 5 dinosaurs moving would look like. Dr. Bill did make the news earlier this summer with his announcement that his computer model of T. Rex showed T. Rex was fast as well as fearsome.

Well, a model in which the knee hardly bends while running, no quadriceps is visible, and the longitudinal arch of the foot (and plantar fascia) is not playing a role in gait is also rubbish. Without a computer model, one can see what happens to the gait in which one has a rupture of the Achilles tendon. There is no active propulsive phase. Erdemir et. al. with Neil Sharkey wrote in JBJS in 2004 about how the plantar fascia may transmit the energy stored in the Achilles tendon to the forefoot. The statement about storage of energy in the tendons was most recently made fairly close to the University of Manchester, in the British Journal Nature by Bramble and Lieberman in 2004. “Collagen-rich tendons and ligaments in the leg store elsastic strain energy during the initial, braking part of the support phase, and then release the energy through recoil during the subsequent propulsive phase. To use these springs effectively the legs flex more in running than in walking…” Further back Cagagna, Thys and Zamboni made similar hypotheses in 1976 and Ker et.al. in 1987 wrote an article titled “The spring in the arch of the human foot” which included the foot within the gait model as a place of energy storage. Certainly the running shoe market will soon include energy return systems which mimic the storage system of the plantar fascia via storage within bending plates of metal or plastic rather than “springs”. Computer models must be made to mimic the system they purportedly model and therefore we need tendons present in the model. In other literature they are often modeled and pictured as being the equivalent of a “spring”.

Please note, there is a statement in much of the lay press indicating that gorillas do not have an Achilles tendon. They do, it is, however, much smaller and shorter than that found in humans.

A debate over who was best able to run fast and at what stage of our evolution could we do this is of interest, but another interesting question is when did we figure out that we could set traps for our prey and not run or make weapons, be it a stick, a spear, or a bow and arrow, that would keep us from having to run quite as fast as our prey. Since our sprinting speed can only be sustained for around 15 seconds, at some point our ancestors found that it is not the sprint that helps us, but our intermediate distance running or our endurance running that will allows us catch up and serve up our prey. And better yet, our brain, which will let us run smart, and perhaps, not have to run much at all. Then all our running can eventually evolve to running for pleasure and less to finding food. Hence the evolution of food down to a power bar or a squeezable container of gel.

It is important also to note that much goes into having an upright bipedal gait and at least as much into having a running gait. While many animals are considered to have adapted to more forms of gait than humans, I’d view it as more than just two forms of gait. Just watch a steeple chaser to see more than 2 in just a few seconds. Well, I wasn’t entirely serious about the steeple chaser. I view our different speeds and distances that we cover as contributing to different gait types. These gaits involve different energy systems to power them. A sprint of 100 meters, a sprint of 800 meters, a mile race, and a marathon employ different aspects of our energy systems to accomplish them. While our speed will not overcome most of our competitors, our sagely wisdom, ability to plan and yes, even our intermediate and distance running will have a tremendous impact.

I also like both computers and computer models. I look forward to seeing a quadriceps, gluteal muscles, posterior tibialis muscles and many other factors added into the computer based simulation. Just a few years ago at the Iowa College of Podiatric Medicine I viewed a work in progress: a simulation of gait using a cadaver limb with the lower limb muscles loaded and pre-programmed to tense at the time in which a normal gait would have them do so. This “action” model nicknamed “Dead Man Walking” was set up so that one could alter the use of the lower limb muscles in a stride. Hopefully more will come of both kinds of studies and those writing about it will describe accurately the work and the words of the author. I plan to seek out more of Dr. Seller’s own words, which are thought provoking, and a bit less of the third party interpretation.

References:

Bramble DM and Lieberman DE (2004) Endurance running and the Evolution of Homo. Nature, 432: 345-352.

Erdemir,A Hamel,AJ, Fauth, AR, Piazza,SJ Sharkey,N
The Journal of Bone and Joint Surgery (American) 86:546-552 (2004)
Dynamic Loading of the Plantar Aponeurosis in Walking
Ker, RF et. al. The spring in the arch of the human foot. Nature 325: 147-149 (1987)

Cavagna GA et. al. The sources of external work in level walking and running. J. Physiol. Lond 262: 639-657.

Hicks JH: The foot as support. Acta Anat (Basel) 25: 34, 1955.

Lapidus PW: Misconceptions about the springiness of the longitudinal arch of the foot. Arch Surg 46:410, 1943.

Ward, E et. al. 2003. In Vivo Forces in the Plantar Fascia During the Stance Phase of Gait. Journal of the American Podiatric Medical Association Volume 93 Number 6 429-442 2003

Quadrupedal Human Gait (repost 09/2010)

Bipedalism (walking upright on two limbs) in hominids is considered a logical and efficient means of locomotion arrived at via hundreds of millions of years of evolution. At the newly instituted PLOS group of blogs a thorough post appearing on the newly moved blog Neuroanthropology describes Turkish individuals who are quadripedal and exhibit what is called Uner Tan Syndrome (UTS). There is some conjecture on the cause of this condition and on whether or not it is evolutionary atavism.

Human Quadrupeds
Human Quadrupeds

This syndrome was first discovered in 2005 by Üner Tan of Cukurova University in Turkey who is also a member of the Turkish Academy of Sciences.

I note that the quadripedal humans seem to be scurrying along at a fair clip. They are not wearing any coverings on their hands. From the photo it is difficult to determine what they wear on their feet. The video below does show some foot gear. At least some of the quadrupedal humans seem to have the forelimb contact on the heel of the hand, but others may contact further foreward.  I’m sure this will be looked at closer. Evolutionary analysis and better coaching may lead to improved 4 limb locomotion for these individuals. So far I have not come across any reports of any quadrupedal long distance endurance events.

This does appear to be a real syndrome however and the blog describes the symptoms and results of MRI and PET scans on subjects. The findings include:

“signs of cerebellar dysfunction including: intention tremor, dysdiadochokinesis (inability to execute rapidly alternating movements particularly of the limbs), dysmetria (lack of coordination of movement typified by under- or over-shooting the intended position), and nystagmus (involuntary rhythmic eye movement, with the eyes moving quickly in one direction, and then slowly in the other). However, the cerebellar signs are relatively mild, and they are no more pronounced in the quadrupeds than in the one affected brother who walks bipedally.”

My take on this is that the syndrome appears to be an inherited motor and sensory issue (HMSN). There are many disorders in this category with a variety of symptoms. Some of the more common ones include Refsum’s syndrome and Charcot-Marie-Tooth disease .

Both a BBC and PBS Nova documentary have been produced on this condition.

Links:

Neuroanthropology Blog Post on “Human Quadrupeds” by Greg Downs – thorough discussion, many reference links

John Hawks Discussion on “Turkish Tetrapods” in 2006

A New Syndrome With Quadripedal Gait Tan, U. Int J Neurosci. 2006 Mar;116(3):361-9.

Family That Walks on all 4s (NOVA show)

The Muppets on Early Gait Development

Walk Don’t Run: Ambling Along With 4.5 Million Year Old Flat Feet

by PRIBUT on OCTOBER 1, 2009

Ambling Along With 4.5 Million Year Old Flat Feet

A hominid species predating Lucy, (Australopithecus africanus) has been more fully described. Journalists have had first crack at the issue of Science in which the updated description of the species,  Ardipithecus ramidus (from 4.5 million years ago), appears. The rest of us could only see this issue late in the day.  The recently studied Ardipithecus specimens include the feet, which were clearly missing on Lucy (from 3.2 million years ago), but present among a limited set of other Australopithecus specimens. Ardipithecus was originally discovered in 1994 in Ethiopia.

The treasure trove of the day are the eleven fresh papers detailing  Ardipithecus and it’s (with a delay in publication for years) environment including botanical and other specimens found locally, the anatomy, and evolutionary conjectures all published in Science magazine. Details on excavation, locale, personnel, CT scans, three-dimensional reconstruction, dimensions and sizes of the specimens, were included in this comprehensive set of articles.

Ardipithecus was thought to live and spend time in trees, but would carefully climb rather than swing from the branches. Ardipithecus was also believed to spend time foraging for food, primarily plant based, on the ground while moving in a bipedal manner. Australopithecus was not a runner, nor is it likely with feet less well adapted  was Ardipithecus. Among other lower extremity differences between Homo erectus and Ardipithecus were flatter feet and an opposable big toe (metatarsus primus varus – actually  metatarsus primus adductus – a large angle in stance between the first and second metatarsal bones – but I’ll have to check out more photos and study the  articles in detail in Science magazine). If Ardipithecus twiddled her thumbs she could likely also twiddle her opposable big toes. Speaking of toes, one of the changes that is thought to make running possible for the later hominids was a shortening of the length of toes, in addition to an increase in arch height, and a host of other biomechanical changes.

An opposable big toe with a non-functional first ray makes for a decidedly different bipedal gait than even Lucy had. The tight grouping of the cuneiforms present in later hominids allowed the first ray to function effectively in weight transfer and propulsion rather than the little it could do as an opposable digit without stability in ground based bipedal gait. Of course a humanoid great toe does not offer much assistance in the trees. An important feature to note is that Ardipithecus did not knuckle walk, as can be determined from the wrist and hand structure, during bipedal gait, although the upper extremities were long. Nor did Ardipithecus appear to brachiate or swing through the tree branches.

Below are images of the upcoming cover of Science magazine with Ardipithecus on the cover and an image of Lucy missing her feet.

Update: Freely available articles at Science

Ardipithecus
Ardipithecus

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Lucy On The Ground With No Toes
Lucy on the ground with no toes

Related Articles

Movement and Exercise Spurred Evolutionary Brain Development

In The Beginning: We Were Made To Stand Upright

Walk This Way (Early Foot Prints  of Homo erectus)

Additional References:

Fossils, feet and the evolution of human bipedal locomotion W E H Harcourt-Smith and L C Aiello. J Anat. 2004 May; 204(5) : 403–416.

 

 

 

 

 

 

 

 

 

 

 

 

Bonus Music: Ventures – “Walk Don’t Run” – Primitive filming (B&W)

Evolution and Exercise: What Made The Brain Get Bigger

by PRIBUT on AUGUST 3, 2009 (retrieved from Internet Archive )

Stimulating Brain Development: Evolution Of The Brain Spurred By Movement (a speculative hypothesis)

We previously mentioned the early hominid development of upright, obligatory, habitual bipedal posture mentioning the richer protein and calorie dense food which may have enabled better brain development. We’ll expand on that a bit with a “big think” and take it down a slightly different road. And we can have a bit of fun with a speculative hypothesis.

My thought (and hypothesis) is that exercise, viewed as aerobic movement, was the spur to development of a larger brain as is found in later hominids and modern humans. Tool making, enhanced socialization, all other more modern features and the larger cortex itself derive from motion, movement, and the positive effect that “exercise” has on the chemistry of the brain.

As we stop and think about what made the brain enlarge we hear those who say that bipedal movement freed up our hands. Now you can walk and juggle or do other tricks.  Another theory posits that early hominids could now carry food back to their tribe, make tools, ultimately jewelry and developed other useful talents. Whatever occurred likely was multi-factorial and not a simple single means event.

In keeping with Darwinian principles, it is incorrect to say that the environment created changes. We need to look to see what environmental features were taken advantage of by those best prepared to do so. Mutations are random, selection is purposeful, and geared towards the survival of those most fit for the environment. There are a variety of phenotypes present at any time, and those exhibiting desirable and helpful characteristics do survive and pass on those useful genes.

Mammalian brains produce BDNF (brain derived neurotrophic factor) which assists in neural plasticity and in the creation of new neural cross links. Humans today moving at high rates of oxygen uptake show that at up to 60% of maximum VO2, several things come into play. The first is an increase in Cerebral Blood Flow (CBF). The CBF increases as does the production of  BDNF and other compounds that among other effects stimulate brain growth and development. These other compounds include IGF-1 (insulin growth factor 1), VEGF (vascular endothelial growth factor), and FGF (fibroblast growth factor).

Bathing the brain in this enhanced biochemical “miracle grow” mix, likely would have resulted in superior neural growth and response for those who were best able to respond to this physical and neurological environment.  This seems to have been a contributing factor in the maximal development of the early hominid brain, and continued down through the hominid line.brain

Those most able to respond to the biochemical results of their activity of  motion, movement, and gathering would have become the smartest of the lot and been most likely to survive . They would be better suited for survival and more able to pass on their genes.  Bipedal movement in hominids was first to be short in duration. Lasting for only a limited distance and allowed for limited scavenging.  Ultimately it resulted in habitual and obligate bipedalism of longer duration, and finally in walking and then, later, running.

There have been debates over the energetics of bipedal motion versus brachiation and advantages over older forms of quadripedal locomotion. But with the thought that nothing gets wasted, if the energetics don’t balance perfectly it is probable that the energy itself that may not have been optimally efficient for walking, certainly was put to excellent use in the development, enhancement, and gradual evolution of the hominid and ultimately modern human brain.

Bipedal walking allowed the former tree apes a  better and more easily sustained motion. This  over the course of time, possibly led to persistence hunting, or at the least an expanded range for gathering, foraging, and then much later hunting. And the migration out of Africa was another sustained effort and may have stimulated brain development.

Sensory stimuli, socialization, diet, and many factors went into brain evolution and development. Then, as now, it is likely that the sustained efforts of moving increased focus, attention, and concentration. Creating mental maps of where they had been, and how to return home gave their small brains a work out. And speculating a bit, ultimately mental maps led to many other things and perhaps even primitive games of hide and seek.  Later came blind folded chess and google maps.

Many facets of evolutionary thought are interesting and valuable. Socialization and network theory, the role of sensory stimulation all are explorable, viable theories and played a major role in evolution. Here we’ve brought into play another facet of hominid evolution not previously described. The energetics and resultant neurochemical (and other changes) as a result of  motion, movement and exercise is a contributing and driving force for brain development and evolution. Put this in the context of the fact that everything moves and there is nothing entirely still in the universe, we have another small factor to consider about our world and how we and it have evolved.

So it seems we weren’t just born to walk or run. We were born to think, develop and evolve. In fact, we’ve evolved to evolve. And evolution continues today. If your thoughts stop with barefoot running, and you think our evolution stopped then, you’ve got a lot more thinking and catching up to do. Exercise and movement are good for what ails you, and assisted in the development of today’s modern human brain.

(Outline presented at American Podiatric Medical Association Annual Scientific Seminar. August 1, 2009. Toronto, Canada)

(Link on Wayback Machine – Internet Archive)