Contents

25 August 2017
Vol 357, Issue 6353

About The Cover

Cover image expansion

COVER A Hadza hunter-gatherer from Tanzania holding a piece of honeycomb. The microbiome of these people, which serves as an approximation of humanity's ancestral microbiome, follows a cyclic pattern that mirrors the seasonality of their diet. The most dynamic microbial lineages across these seasonal shifts are among those that are rare or undetectable in industrialized populations. See pages 754 and 802.
Photo: MATTHIEU PALEY/National Geographic Creative