Why did octopuses become so smart?
Ed Yong writes: A small shark spots its prey—a meaty, seemingly defenseless octopus. The shark ambushes, and then, in one of the most astonishing sequences in the series Blue Planet II, the octopus escapes. First, it shoves one of its arms into the predator’s vulnerable gills. Once released, it moves to protect itself—it grabs discarded seashells and swiftly arranges them into a defensive dome. Thanks to acts like these, cephalopods—the group that includes octopuses, squid, and cuttlefish—have become renowned for…