THE LATEST: Download the PNAS Full-Text App today, now available for Apple and Android devices.

Early Edition

New papers posted daily


Featured Image

McMurdo Sound

Interactions between Antarctic ice and phytoplankton.
Image Gallery »


Front Matter

  • post thumbnail
  • News Feature: Prehistoric animals, in living color
    Paleontologists are looking beyond bones to reveal the hues of prehistoric animals that vanished millions of years ago. But the young field has its share of disagreements. Image courtesy of Michael DiGiorgio (artist).






  • post thumbnail
  • Neuronal density and bird intelligence
    Researchers report that parrot and songbird brains had greater neuronal density and a greater proportion of neurons in the forebrain than in mammalian brains of similar mass, suggesting a basis for the advanced cognitive abilities of certain birds.
  • Science Icon
  • Guardian Icon




PNAS Direct to Your Inbox

Or subscribe to one of our RSS Feeds »



Top Articles

  1. Cluster failure: Why fMRI inferences for spatial extent have inflated false-positive rates
  2. Birds have primate-like numbers of neurons in the forebrain
  3. Early farmers from across Europe directly descended from Neolithic Aegeans
  4. Silicic volcanism on Mars evidenced by tridymite in high-SiO2 sedimentary rock at Gale crater
  5. Analysis and valuation of the health and climate change cobenefits of dietary change

50 Most-Read Articles »


Follow PNAS on Facebook