Another clickbait title, it should really be “an unproven theory for why mammals need R.E.M. sleep based on seals” Or even “R.E.M. sleep might be a trait evol

Another clickbait title, it should really be “an unproven theory for why mammals need R.E.M. sleep based on seals” Or even “R.E.M. sleep might be a trait evolved to keep your brain warm at night”