Earth is missing a huge chunk of its geological record before the Cambrian period 538 million years ago, when complex life emerged. A new study suggests that the gap was caused by the rise and fall of ancient supercontinents.  

Archaeologists have discovered the oldest direct evidence of psychoactive cannabis use in a Siberian tomb that was used for human and horse sacrifices, a finding that sheds light on ancient rituals and could help revive wild strains of cannabis lost to time.