First and foremost I'm a huge believer in the barefoot lifestyle for those who can tolerate it, and I'm glad you threw in the "do it gradually' caveat.
As chiropractors we're taught that faulty biomechanics of the feet lead to pelvic instability. Because the pelvis is the foundation for the entire spine this biomechanical unsoundness eventually leads to spinal misalignment.
In chiropractic school we're taught to stabilize the feet with custom made orthotics, and the company Foot Levelers had a big presence in the clinical setting at my school. I didn't get in to prescribing orthotics until my 3rd year in practice, and in general don't advocate their use.
There are some cases with patients who just plain need them. Can't walk without them. Can barely stand without their orthotics for more than a few minutes before experiencing terrific back and pelvic pain.
I suppose this further proves the idea that we are all unique individuals. Every body's body is different. We are not like cars. If you're a mechanic and you can fix a 1992 Chevy Cavalier then you can fix ANY 1992 Chevy Cavalier. If I'm a doctor and I can fix someone that was born in 1992 that doesn't mean I can fix EVERYONE that was born in 1992.
That's why doctors get paid more than mechanics, though.
Anyways I digress from my initial point. Just a few comments on some of your statements from today's Barefoot article and how they might tie in to natural selection:
"There are objective truths out there, and the objective truth is that most people aren’t born with genetically defective feet."
True. Thousands of years ago those that were bron with defective feet wouldn't have survived long enough to reproduce without family members to take care of their survival needs.
Sidenote: From a Chinese Medicine perspective, the arches in the feet may flatten due to issues with the small intestine and/or colon, as the reflex points for these organs lie in the heart of the longitudinal arches of the feet. See link below for a foot reflexology chart to see if YOUR foot pain may be stemming from an organ:
"Everyone’s imperfect, sure, but for the most part we’ve all got the same basic equipment with the same basic biomechanics working under the hood. Unless you have a birth defect, no one is born with feet that “won’t work right” or that “require shoes”. The flat footed (no arch) argument doesn’t stand up as an excuse, except when you’ve already spent a lifetime coddling your feet in supportive casts."
See this is what I love about Mark--he doesnt' hold back! I couldn't agree more, and it's unfortunate that modern life seems to promote such an UnGroklike Lifestyle that promotes the degeneration of our feet. In ancient times our feet were in direct contact with the Earth. We felt the pulse of the Earth in our feet and felt it's energy rise up and fill our bodies. And we respected the Earth a lot more back then, too. Hmmm...
To this day the capoeiristas de Brasil still play barefoot. See youtube video below for a great game:
"A cautionary word that anyone transitioning to a barefoot lifestyle should take it VERY easy at first."
Grok on, brother.