Why Do We Sleep? Well, Why Not?

Some scientists argue that the purpose of sleep may not be restorative. In fact, they argue that the very question “why do we sleep?” is mistaken, and that the real question should be “why are we awake?”. If you are safe and warm and fed, it is a waste of energy to be awake and moving around (and possibly getting into trouble). Far better, this argument goes, is to be awake only when you have to and sleep when it suits you.

I like that. Although I don’t see how it would explain why we need to sleep.

Below 30°N, Everything Disappears

Gregory Cochran explores the geography of scientific productivity:

You might suspect that the pattern would change if we raised the bar, looked at more extreme and important examples of scientific creativity, rather than counting every paper. It does. If you look at Nobel prizes in the sciences, or Fields medals, the differences become starker. Whole nations disappear. Single individuals outdo whole civilizations.

Australian Megafauna Extinction Caused by Humans

From the BBC:

Humans hunted Australia’s giant vertebrates to extinction about 40,000 years ago, the latest research published in Science has concluded.
…
Human-lit fire – deliberately targeted and more frequent than lightning – had a devastating effect of plants that had previously been protected.

“Any climate change at those times was modest and highly unlikely to affect the outcome,” author Matt McGlone wrote in Science.
…
He said the latest study “supports a mounting number of studies that have argued that climate change was not primarily responsible for the Late Pleistocene extinctions in other parts of the continent.”