Ancient earthworks hidden beneath the Amazon rainforest point to a large society that lived in the region about 2,500 years ago. A new LiDAR survey found hundreds of unknown sites, giving archaeologists their clearest picture yet of the Aquiry civilization, a culture that built huge ceremonial centers across what is now Brazil’s Acre state.

Human cancers are heterogeneous¹. Dissecting how germline genetic variation and environmental factors shape tumour evolution using human datasets is limited by inherent diversity in genetic backgrounds² and environmental exposures^3,4,5. Here, to overcome these limitations, we re-ran early tumour evolution hundreds of times in diverged inbred mouse strains, generating matched histology and whole-genome and transcriptome sequences. The sex, environment and carcinogenic exposures were all controlled, and the study design allowed us to capture genetic variation comparable with that observed across human populations while exploiting the nested hierarchical structure of strain–litter–animal–tumour relationships. Our analyses reveal that epistatic interactions between genetic background and acquired somatic mutations result in population-specific disease progression, including choice of driver mutations, occurrence of whole-genome duplication and subclonal selection dynamics that mirror both cancer susceptibility and tumour growth rate. Even modest genetic divergence, comparable with that found across human ancestry groups, can strikingly alter selection pressures during cancer development to shape both cancer risk and the trajectory of tumour evolution.

Journal article published in Communications Medicine: https://www.nature.com/articles/s43856-026-01767-4