[Crumbs]

So-called “mismatch diseases” are “defined as diseases that result from our Paleolithic bodies being poorly or inadequately adapted to certain modern behaviors and conditions” (chapter 7).
According to David Lieberman, many non-infectious mismatch diseases are mental disorders, like
Alzheimer’s disease
Chronic fatigue syndrome
Depression
Eating disorders
Fibromyalgia
Hypertension
OCD
and possibly many more (Table 3).

Lieberman’s elaborations neatly fit into the organismic self-regulation within an organism/environment space. The author gives many examples about how exactly our evolutionary-shaped bodies get in trouble with modern ways of living (“having paleolithic bodies in a post-paleolithic world”), including topics like cancer, wearing shoes vs. running barefoot, disuse of mental capacities, overweight, overexceeding hygiene (“just because we can live lives of exceptional cleanliness and comfort doesn’t mean they are good for us”), diabetes, short-sightedness, etc.

For example, about sitting in a chair (chapter 12):
“When you sit in a standard chair, your hips and knees are flexed at right angles, a position sitting can permanently shorten the hip flexors. Then, when you stand, your shortened hip flexors are tight, so they tilt the pelvis forward leading to an exaggerated lumbar curve. Your ham-string muscle along the back of the thigh then must contract to counter this curvature, tilting your pelvis backward, leading to a flat-back posture, which hunches your shoulders forward. Fortunately, stretching effectively increases muscle length and flexibility.”

Concluding that “hunter-gatherers use their backs moderately–neither as intensively as subsistence famers nor as minimally as sedentary office workers”.

Another fascinating result is the possibility that painful wisdom teeth may be related to not chewing enough during early childhood (leading to the development of smaller jaws that then cannot provide the necessary space). Yet another, that bone strength seems to be mainly determined until age 20-25 based on a “no strain, no gain” principle (“[a]fter then, there is little you can do to make your bones bigger, and soon thereafter your skeleton starts to lose bone for the rest of your life”; chapter 11)

Lieberman, D. (2013). The story of the human body: Evolution, health, and disease. New York: Pantheon Books.