For only a few years, it has been clear that bacteria are completely dominant in a healthy human being: On top of our ten billion body cells, there are one hundred billion microbial cells that play a role in our metabolism. This enormously increases the options for our bodily processes: If we include the microbes’ genes, then we have over 100,000 genes at our disposal, as opposed to just over 20,000.

The accelerating pace of society resets our internal timers, which then go off more often in response to slow things, putting us in a constant state of rage and impulsiveness ... We now practically insist that Web pages load in a quarter of a second, when we had no problem with two seconds in 2009 and four seconds in 2006. As of 2012, videos that didn’t load in two seconds had little hope of going viral.

there is no fundamental difference between natural selection and sexual selection. Natural selection occurs any time differential reproduction is afoot, with some genes more successful than others in projecting copies of themselves into future generations. Sexual selection involves competition to acquire and obtain a mate, and is every bit as natural as other forms of selection called upon when it comes to, say, obtaining food, avoiding predators, sleeping when tired, or scratching when itchy.

Sensation seeking is thought to be partly heritable, and can be passed down from parents to their children. The trait is associated with lower anxiety and a blunted response to potentially dangerous situations. One result can be a tendency to underestimate risks, which a recent study linked to an imbalance caused by low amygdala reactivity and less effective inhibition of sensation seeking by the prefrontal cortex.

Nature was full of animals that routinely generated massive forces on their brains without apparent damage. They included bighorn sheep; whales that ram each other; and birds that dive headlong, at 500 feet per second, into the water. How did the animals avoid brain injury? ... It’s widely assumed these animals don’t have problems from a lifetime of head-smashing...but it’s not proven. Maybe woodpeckers or rams don’t live long enough in the wild to develop degenerative conditions like CTE.

pro players could predict the outcome before the ball even left the shooter’s hands. They seemed to know the path of the ball just by looking at the shooter’s body. This effect may have to do with mirror neurons, a special set of neurons that fire specifically when watching or doing a certain action. Since mirror neurons bridge observing and acting, neuroscientists have hypothesized they have a role in a basketball player’s ability to foresee the effects of another player’s actions.

It turns out that much of what might have been considered normal age-related decline is strongly accelerated by disease and malnutrition early in life, even before birth. Babies of malnourished mothers, even those who received adequate nutrition after birth, are found decades later to have substantially elevated incidences of coronary heart disease, stroke, and hypertension. Survivors of childhood smallpox and whooping cough have generally higher levels of mortality in old age.

Gender in humans is on a continuum, coming in scads of variants, where genes, organs, hormones, external appearance, and psychosexual identification can vary independently, and where many people have categories of gender identification going on in their heads (and brains) that bear no resemblance to yours. All with a frequency that, while rare, are no rarer than various human traits we label as “normal.”

Religions don’t have literal DNA... but they can parallel how species mutate. There are key properties of successful genetic mutations that religions must have to succeed...inheritance, variation, and selection. For religions, inheritance means the ability to transmit beliefs, behaviors, and a sense of belonging to new generations. Variation means having the ability to allow for innovations... and selection means having a way to absorb converts and deal with bad mutations...apostates or heretics

Cancer is not linear—it is completely non-linear ... If you biopsy a patient with breast cancer twice in the same day, once in the breast and once in the lymph node, you can get cancer cells with different sequences. Even if you biopsy two different points in the breast, the sequence can be different. This heterogeneity has really only come to light recently ... The only chance we have ... is to do ... micro killing and macro killing at the same time.