WHALES might dream after all. While many mammals are known to undergo REM sleep—the sleep stage characterised by rapid eye movement, muscle jerks and, in humans, dreams—scientists haven’t been able to find convincing evidence of it in whales. Recordings of the electrical activity of the brains of sleeping whales failed to show the characteristic patterns of REM sleep.
So biologist Oleg Lyamin and his colleagues at the Severtsov Institute of Ecology and Evolution in Moscow spied on a captive beluga whale as it slept. The researchers saw muscle jerks that are typical of REM sleep in other animals…
