An analysis of ancient genomes reveals an explosive geographical and demographic spread of modern domestic horses about 4,200 years ago. The findings counter the idea that horses accompanied and mobilized the mass migration of humans from the Eurasian steppes about 5,000 years ago.

Single crystals of atomically thin sapphire have been prepared at room temperature — something that many scientists thought was impossible. These materials could enable the development of the next generation of transistors for use in miniaturized chips.

Clearance of dying cells is essential to the health of tissues. Study of hair follicles finds that, when follicle stem cells encounter dying neighbours, they become temporarily able to engulf and digest them. The molecular underpinnings of this reveal how clearance is spatially and temporally tuned to maintain tissue fitness.

By tracing the neural circuits that are active when mice anticipate pain relief, neuroscientists find that the placebo effect involves the cerebellum and brain stem — areas that typically mediate ‘lower’ brain functions.