Biologists in the US have shown for the first time that global biodiversity is concentrated within a few disproportionately large groups with exceptional rates of evolutionary diversification. This result suggests that rapid radiations, including adaptive radiations, have generated the majority of life on Earth.

New research from Tulane University found that brown anole lizards in New Orleans carry the highest blood-lead levels ever recorded in a vertebrate — amounts that would be lethal to most other animals — yet they appear unaffected. The study, published this month in Environmental Research, found that the lizards’ blood lead levels exceeded all previously reported values for fish, amphibians, birds, reptiles and mammals.