The vocabulary of evolutionary mismatch

The cumulative cost of holding the body ready, named by McEwen and Stellar in 1993 and estimated from markers such as blood pressure, waist, lipids and stress...

The proposal that depression's symptoms package the mind for sustained thought about a hard social problem.

The build-up of fatty, often calcified plaque in artery walls. It is ancient, found in mummies, yet 85% of Tsimane adults scanned had no coronary calcium at all.

A genus of early hominins, including Lucy at 3.2 million years old, that walked upright while still climbing regularly.

The cell's system for digesting and recycling its own worn-out parts. It joined the hallmarks of aging in 2023, and nobody can yet measure it in a living person.

Bernie Krause's term for the collective voice of a habitat's organisms, set beside geophony, the sound of wind and water, and anthropophony, the sound people make.

Regions, Sardinia, Okinawa and Ikaria among them, said to hold unusual numbers of very old people.

Fat tissue that makes heat rather than storing energy, switched on by cold. Its output in adults runs to roughly 15 to 25 kilocalories a day: a pilot light, not a...

A prolonged but reversible rise in the excitability of nerve cells in the spinal cord and brain, so touch hurts and pain hurts more.

The way defaults and framing shape what people do without removing any option, as in automatic pension enrollment and presumed consent for organ donation.

The roughly 24-hour cycle kept by a self-winding genetic loop found in tissues throughout the body.

Yaakov Stern's account of why two people with similar Alzheimer's pathology can differ greatly in impairment.

The involuntary gasp, hyperventilation and surge in blood pressure that follow sudden skin cooling.

James Fries's 1980 proposal that illness at the end of life could be squeezed into a shorter span if its onset were delayed faster than death.

The absence of any outward signal of human fertility. Paternity confidence, paternity confusion and alliance-building all have advocates, and no test has settled...

Herman Pontzer's proposal that daily energy use levels off as activity rises, because active bodies spend less elsewhere.

A system in which adults besides the mother, called alloparents, invest in raising young: grandmothers, older siblings, aunts, unrelated group members.

T.S. Kemp's account of how warm blood evolved: many structures changing together, keeping the animal a working whole at every step.

The main human glucocorticoid, released tens of minutes into a stress response.

Brain regions, including medial prefrontal and posterior cingulate cortex, that grow more active when no task holds the mind.

Millet farmers of Mali whose menstrual huts let Beverly Strassmann count women's cycles. A Dogon woman who lived to menopause had a median of about 109 periods.

Robert Dudley's proposal that the smell of ethanol in ripening fruit led ancestral primates to food, and that modern drinking misfires that attraction.

About 150, extrapolated from a relationship between neocortex size and group size across primates.

Daniel Lieberman's term for the loop in which medicine treats the symptoms of mismatch diseases while the environments causing them are passed on.

The two to four million glands that cool the body by evaporation, about 10 times denser in human skin than a chimpanzee's and not tied to the rhythm of breathing.

The feedback loop that grows the eyeball until its length matches its focusing power, using blur on the retina as its guide.

Making your own body heat, at five to ten times a cold-blooded animal's oxygen cost.

Dietary energy in, minus energy burned in exercise, per kilogram of fat-free mass.

A gene in the oxygen-sensing pathway. Tibetan variants, inherited from Denisovans, hold down the red-cell response to thin air and spare the heart the strain of...

Abdel Omran's 1971 framework describing a shift from an age of pestilence and famine, through receding pandemics, to an age of degenerative and man-made diseases.

Chemical marks on DNA and its packing proteins that change how genes are read without changing the sequence.

This book's three marks, a simplified cousin of the GRADE system: ●●● strong, ●●○ probable, ●○○ emerging, small, animal-only or contested. (Prologue)

The study of why bodies are vulnerable to disease, called Darwinian medicine by Williams and Nesse in 1991.

A condition more common or severe because an organism is imperfectly adapted to a novel environment.

Aiello and Wheeler's 1995 proposal that the human brain was paid for by a shrunken gut.

Carbohydrate human enzymes cannot break down, left for colon bacteria to ferment into short-chain fatty acids.

Shinrin-yoku, named by a Japanese ministry in 1982. Its immune claims rest on very small unrandomized studies; the better-measured effects are modest short-term...

Periods stopping because the reproductive axis has shut down under low energy availability. It can occur without visible weight loss and needs clinical assessment.

A gut hormone released after a meal that boosts insulin, slows stomach emptying and reduces eating.

A proposed route by which fluid enters the brain along arteries and leaves along veins, carrying waste. Whether sleep speeds that clearance or slows it is disputed.

Kristen Hawkes and colleagues' proposal that older women's foraging pays for human life history, letting mothers wean earlier and conceive again sooner.

Hunter-gatherers of Tanzania, roughly 1,200 of them, the most-studied foraging population in this book.

Women divers of Jeju, Korea. Before wetsuits arrived in 1977 their winter metabolic rate ran about 35% above the standard; within a few years of covering up, the...

Twelve cellular processes named in a 2023 review, from telomere attrition to chronic inflammation.

This book's name for the practical section closing most chapters, with doses, grades and cautions.

A label for one unbroken ancestral line, traced through the Y chromosome or mitochondrial DNA.

The beat-to-beat variation in the spacing of the pulse, tracking the vagus nerve's influence on the heart.

A conserved emergency response, made quickly under stress and named for the heat shock that first exposed the pattern, in fruit flies in 1962.

The share of variation in a trait, within one population under one set of conditions, owed to genetic differences.

Complex sugars in human milk that the infant cannot digest. They arrive intact in the colon and feed favored bacteria: nutrition for the baby's microbes, not the...

David Strachan's 1989 suggestion that childhood infection carried by older siblings protects against hay fever.

Blood sodium at or below 135 millimoles per liter. In endurance events it comes mainly from drinking more than the body loses, and at its extreme it swells the...

Raichlen, Pontzer and colleagues' proposal that human physiology expects the muscle work of squatting, kneeling and ground-sitting.

Kevin Tracey's circuit in which the brain detects inflammation and answers down the vagus nerve, telling immune cells to quiet.

A study of 10,079 adults at 52 centers worldwide, measuring sodium in 24-hour urine.

San hunter-gatherers of the Kalahari, also written !Kung, whose work diaries produced the idea of the original affluent society.

An island in Papua New Guinea where a 1990 survey of 213 adults, by interview and resting ECG rather than autopsy or scan, found no case of stroke, sudden death or...

Keeping the milk-digesting enzyme switched on into adulthood. It arose at least four times through different mutations, long after people began consuming milk, and...

Raised permeability of the gut lining, real and measurable in celiac and inflammatory bowel disease.

The randomized trial in which 640 high-risk babies ate or avoided peanut until age five.

A hormone made by fat. Its main job appears to be reporting starvation rather than preventing obesity: it falls when food runs short, and blocking that fall blunts...

Yuval Noah Harari's name for the pattern in which a labor-saving technology is adopted, life expands to fill the capacity, and the technology becomes compulsory.

Teeth that do not meet as they should: crowding, overbite, crossbite. Jaws have shortened since farming while tooth size changes only over millennia, and in animals...

Metabolic dysfunction-associated steatotic liver disease, the 2023 renaming of nonalcoholic fatty liver disease.

H.M. Frost's model in which bone remodels itself to the loads placed on it, sensed by cells called osteocytes.

The light-sensitive pigment in a third class of retinal cells, wired to the body clock rather than to vision.

A method using inherited genetic variants as natural instruments to test whether an exposure causes an outcome.

The microbes living in and on the body: about 38 trillion bacteria in a 70 kg reference man, nearly all in the colon and weighing about 0.2 kg in total.

Footwear with little cushioning or raised heel, and going without. A 2010 study found that habitually barefoot runners landing on the forefoot produced impact peaks...

The summary block closing most chapters, naming the system, what it expects, what it gets, what happens in the gap, the handrail and the strength of the evidence.

Nearsightedness, produced by an eyeball grown too long. It affects 80 to 90% of school-leavers in East Asia, and outdoor time in childhood roughly halves the rate...

The period of early farming, beginning 12,000 to 11,000 years ago. Its skeletons show, on average, shorter stature, more tooth decay and more infection than the...

A third category beside pain from damaged tissue and from damaged nerves, seen in fibromyalgia and tension-type headache.

Gordon Walls's 1942 argument that mammals passed through a nocturnal phase costing them visual equipment reptiles and birds still carry.

Sherwood Washburn's 1960 proposal that human babies are born early because a bipedal pelvis cannot pass a finished head.

Graham Rook's replacement for the hygiene hypothesis: immune regulation depends on organisms present throughout mammalian evolution, such as environmental...

Steven Bratman's term for a diet undertaken for health that has tightened into malnutrition or a life that no longer works. Its marker is impairment, not virtue.

Kelly Baron's 2017 name for patients chasing the perfect sleep score a wearable reports, trusting the device more than how they feel.

The Iceman, found in the Alps in 1991, dead between 3350 and 3120 BCE with whipworm, worn joints, calcified arteries and genetic risk for type 2 diabetes.

The long stretch of human prehistory before farming. This book uses it for chronology, not as a menu: Marlene Zuk's objection is that no single ancestral...

Running or walking prey to exhaustion in the heat. Louis Liebenberg documented 10 in the central Kalahari, and historical accounts show the tactic was widespread...

The puzzle that animals with a thousand times more cells than humans do not get proportionally more cancer.

Per- and polyfluoroalkyl substances, industrial chemicals the liver cannot break down.

A score summing many gene variants of tiny individual effect. It shifts a probability rather than making a diagnosis, and works less well in ancestries thinly...

Stephen Porges's account of a distinct vagal circuit producing a calm-and-connect state.

The signal dopamine neurons carry: a burst when a reward beats prediction, baseline when it matches, a dip when it fails to come.

Also called Tarahumara, farmers and runners of Chihuahua, Mexico. Researchers working with them named the popular romance the "fallacy of the athletic savage": they...

Immune cells that damp down immune responses, controlled by the gene FOXP3. Their discovery won the 2025 Nobel Prize, and the Nobel Assembly called them the immune...

Slow breathing at roughly five to six breaths a minute, the pace at which breath-linked swings in heart rate grow largest.

Ellen Sandseter's six categories of the trouble children seek out: heights, speed, dangerous tools, dangerous elements, rough-and-tumble, and going off alone.

The age-related loss of muscle mass and strength, now screened for with grip strength or gait speed: what a muscle can do predicts falls and death better than its...

Waking time spent sitting, reclining or lying at a low energy cost. It differs from physical inactivity, meaning too little activity to meet the guidelines; a...

The state of a cell that is alive and busy but permanently out of the division business.

Carrying one copy of the sickle hemoglobin allele protects against severe malaria; two copies cause sickle cell disease.

The lethargy, low mood and lost appetite that travel with fever, argued in 1988 to be an organized strategy rather than debilitation.

Sitting on the floor and standing up again, scored from 10 with a point lost for each hand or knee used.

A measure of how consistent sleep timing is from night to night. Across nearly 61,000 accelerometer-wearing adults it predicted death better than sleep duration did.

Randolph Nesse's explanation for why defenses such as fever, pain and anxiety fire on many false alarms: when the response is cheap and missing a threat is fatal...

Robin Dunbar's 1998 argument that primate brains grew to manage social relationships.

The objective state of having few contacts, distinct from loneliness, the felt lack of the connection you want.

The gap between the sleep timing a person's clock wants and the timing work and school impose, paid back at weekends. It tracks higher body mass index.

Referral by a health service to choirs, walking groups, gardening or volunteering rather than to a prescription pad.

An exaggerated version of a natural signal that draws a stronger response than the real thing, such as the oversized model egg an oystercatcher prefers to her own.

Low-grade inflammation running for years with no infection to justify it, proposed in 2019 as a shared thread through cardiovascular disease, cancer, diabetes and...

The repeated cap of DNA and protein at the end of a chromosome, shortening with each cell division.

The band in which the body holds core temperature by adjusting skin blood flow alone, without shivering or sweating: roughly 15 to 25°C (59 to 77°F) for a clothed...

James Neel's 1962 proposal that genes favoring efficient fat storage were selected by famine and turned harmful with plenty.

Confining meals to a fixed daily window. In two randomized trials it added no weight loss beyond the calorie awareness that came with it: a tool rather than a...

A 1993 laboratory procedure: 10 minutes of dread, then a mock job talk and serial subtraction before judges.

Forager-horticulturalists of the Bolivian Amazon, with the lowest coronary artery calcium reported anywhere.

Pastoralists of northwest Kenya who get about 62% of their calories from milk.

The NOVA classification's term for industrial assemblies of substances extracted from foods, marked by ingredients never or rarely used in kitchens.

The savory taste of amino acids, named by Kikunae Ikeda in 1908 after he isolated monosodium glutamate from kombu.

The longest cranial nerve, running from the brainstem to heart, lungs, gut, liver and spleen, and the main channel of the parasympathetic nervous system.

Vigorous intermittent lifestyle physical activity: short bursts of hard effort folded into ordinary life, such as stairs taken fast.

The vitamin the skin makes when ultraviolet B light strikes a cholesterol-like molecule, a process melanin slows without stopping.

The most oxygen the body can use at full effort. This aerobic ceiling falls 3 to 6% per decade in the 20s and 30s and more than 20% per decade from the 70s.

A people of Venezuela and Brazil whose systolic blood pressure showed no measurable rise with age, and whose sodium intake was the lowest in INTERSALT.