Scientists show that many insect groups like beetles and butterflies have fantastic numbers of species because these groups are so old. In contrast, less diverse groups, like mammals and birds, are evolutionarily younger. This is a surprisingly simple answer to a fundamental biological puzzle.
Exposure to levels of lead that are similar to those measured in lead-intoxicated children reduces the birth and survival of new neurons (neurogenesis) in the brain. A study of young adult rats provides evidence that explains exactly how exposure to lead during brain development produces learning deficits.
Giolon writes: Ars Technica is reporting that the plan to enter daylight savings early in order to save power has been largely a bust:
"As it turns out, the US Department of Energy (and almost everyone else except members of Congress) was correct when they predicted that there would be little energy savings. This echoed concerns voiced after a similar experiment was attempted in Australia. Critics pointed out a basic fact: the gains in the morning will be offset by the losses at night, and vice-versa, at both ends of the switch. That appears to be exactly what happened."