Hannibal crossed the Alps with a large army containing 37 war elephants in 218 BC. Details of his route have scholars ...

Contributed by John B. Goodenough, September 30, 2016 (sent for review August 24, 2016; reviewed by Ken Poeppelmeier and Jean-Marie Tarascon) ...

Social wound care plays a life-saving role in taxa as diverse as primates, ungulates, and insects. Yet the organizational principles that underlie this behavior remain unknown. In eusocial animals ...

Fungi often transition between ecological roles, acting as pathogens, symbionts, and decomposers, yet the mechanisms enabling such lifestyle flexibility remain unclear. By comparing early and recently ...

Hamiltonian Systems and Transformation in Hilbert Space ...

Directed Fertilization in Maize For more than 40 y, entomologists have attempted to estimate the number of insect species on Earth, with the current consensus—the figure most experts accept—at about ...

Edited by Ashley Steed, Washington University in St. Louis School of Medicine, St. Louis, MO; received July 20, 2025; accepted January 28, 2026 by Editorial Board Member Michael S. Diamond ...

The PNAS Editorial Board is made up of NAS members who are active scientists and experts in their fields. On submission, your paper is assigned to an Editorial Board member in one of the 31 NAS ...

The Democracy Index finding holds up best. Its negative direct effect on offensive VEI (we use β for SDM coefficients throughout) survives spatial adjustment in every bivariate specification (Table 1) ...

Open in Viewer RoBMA PSMA model-averaged posterior mean effect size estimates with 95% credible intervals and Bayes factors for the absence of the effect for the combined sample or split by either the ...

To help advance the species definition for prokaryotes, we have compared the gene content of 70 closely related and fully sequenced bacterial genomes to identify whether species boundaries exist, and ...

Most of the research papers in random graph theory concern the Erdős–Rényi model 𝒢p, in which each edge is independently chosen with probability p for some given p > 0 (see ref. 3). In such random ...