Genetic mutations lead to new traits — and with the world population now above 7 billion and rising, the chances of genetic mutations that natural selection can potentially act on is only increasing.
Don’t believe us? Inverse presents three examples of recent changes to the human body.
…[T]here has been a gradual decrease in body temperature of 0.05 degrees Fahrenheit every decade. Julie Parsonnet, the study’s senior author and professor of medicine at Stanford University, tells Inverse that this cooling trend is likely linked to a population-wide decline in inflammation, and improved standards of living.
As of several thousand years ago, the enzyme that helps people drink milk without getting sick turned off when people reached adulthood. But later gene mutations that sprung up around the world during a time period of between 2,000 to 20,000 years ago have helped people tolerate dairy well into their dotage.
Compared to other hominins, human bones are weaker and less dense. In a 2015 study, scientists hypothesized that Homo sapiens bones started to weaken around 12,000 years ago — around the time that people started farming more. With settled farming, our diets changed, physical activity changed, and, in turn, our skeletons became lighter — and more fragile.