The spatio-temporal evolution of inflammatory bowel disease across the world follows four epidemiological stages: emergence, acceleration in incidence, compounding prevalence and prevalence equilibrium. Classifying regions by epidemiological stage enables health-care systems to prepare for the evolving global burden.

Ancient and present-day genomes from members of the Indigenous American tribe Picuris Pueblo in the US Southwest show genetic continuity with Ancestral Pueblo individuals from the Chaco Canyon, New Mexico. These results confirm traditional knowledge and contest previous accounts that suggested that the population in the region collapsed before European colonization.

A new class of organometallic compound has been made that has a distinctive geometry and electronic structure — with potential for catalysis and materials science.

First-hand accounts of luminous objects falling in a storm, and a warning against the exploitative trade of tropical butterflies, in our weekly dip into Nature’s archive.