A foul smell makes you step back. A moldy meal kills your appetite. Before your immune system encounters a microbe, disgust may already be helping you avoid it. The evolutionary…
Evolution
69 Articles
Pick up a pen, throw a stone or thread a needle: most people instinctively favor their right hand. Why should evolution produce such an uneven split when our hands look…
When a diver holds their breath, the lungs are not the body’s only oxygen reserve. The spleen contracts, releasing stored red blood cells into circulation and temporarily increasing the blood’s…
Human males grow thick facial hair after puberty—even though most of our body hair became relatively fine. That contrast suggests the beard may have evolved as a social signal. A…
Attachment may look like dependence: a toddler clings to a parent, protests separation and seeks comfort after a fright. Yet its evolutionary function may be almost the opposite—providing enough security…
Human milk contains an evolutionary puzzle: complex sugars that babies largely cannot digest. Why would a mother spend resources manufacturing food her infant cannot directly use? The answer involves another…
Months before saying “mama,” babies begin producing repetitive sounds such as ba-ba-ba and da-da-da. This may sound meaningless, but babbling appears to be a form of structured practice. Each vocalization…
Most mammals cool themselves mainly by panting, seeking shade or reducing activity. Humans possess another remarkable option: we can cover nearly our entire bodies with watery sweat. As sweat evaporates,…
The Animal That Built a World Humans are not the strongest animals on Earth. We cannot outrun a cheetah, overpower a gorilla, smell like a dog, or see like an…
Chimpanzees are often described as our closest living relatives, but some of their behavior can be disturbingly familiar. Researchers have observed groups of chimpanzees deliberately isolating, surrounding, and killing other…