Unlike other creatures, humans can compose, record, and enjoy music. A new study has identified a brain chemical that provides pleasure when people listen to certain music. Where did this amazing ability come from?

When boring into wood in search of food, a woodpecker exerts so much force with each strike that its beak should crumble, its skull should crack, and its brain should be reduced to mush. However, a suite of design features absorbs the shock and ensures that these tragedies do not happen. How are these features able to provide such effective protection?

Among land-dwelling arthropods, the sheer number of just ants and beetles that live and die each year is phenomenal. And ocean krill exist in even higher numbers. Each of these creatures leaves behind an exoskeleton. If it were not for remarkably efficient exoskeleton-eating microbes, the earth would quickly fill up with arthropod carcasses.

For years, museum displays have featured the small extinct ape Australopithecus afarensis. The first specimen, discovered in 1974 and nicknamed "Lucy," was presented as having clearly human eyes, feet, and posture. The feet and posture, however, can only be verified by relevant fossilized structures.

Certain repetitive DNA sequences have long been viewed as "confirmation" of evolution. Since they are not genes that code for proteins, they were considered to be unnecessary. Therefore, they were supposedly available for alterations that would eventually lead to a brand new function within the cell or body after all the "right" mutations had accumulated.