Date: March 2, 2017
Source: University of the Witwatersrand
Why we sleep is one of the enduring unanswered mysteries of modern science. Along with such activities as eating, protecting oneself and reproducing, sleep is one of the major biological imperatives of existence.
Although being asleep precludes these other activities, all animals do sleep. Some, like whales, dolphins, seals and certain birds, do it in a very unusual manner, sleeping with only half their brain at a time, while some sleep quite a lot and others less so.
"While there are many hypotheses regarding the function of sleep, the ultimate purpose of sleep is yet to be discovered," says Prof. Paul Manger, from the School of Anatomical Sciences at Wits University.
The lack of sleep can -- even over a relatively short term -- lead to brain damage, and in the longer term death, as can be seen in the human conditions fatal familial insomnia and sporadic fatal insomnia.
Generally, larger animals tend to sleep less than smaller animals, but do elephants fit this trend?