News

  1. Genetics

    Dolly the Sheep’s cloned sisters aging gracefully

    Cloning doesn’t cause premature aging in sheep.

    By Tina Hesman Saey
  2. Earth

    Ancient air bubbles could revise history of Earth’s oxygen

    Pockets of ancient air trapped in rock salt for around 815 million years suggest that oxygen was abundant well before the first animals appear in the fossil record.

    By Thomas Sumner
  3. Cosmology

    Debate accelerates on universe’s expansion speed

    A puzzling mismatch is plaguing two methods for measuring how fast the universe is expanding.

    By Emily Conover
  4. Earth

    How dinosaurs hopped across an ocean

    Land bridges may have once allowed dinosaurs and other animals to travel between North America and Europe around 150 million years ago, a researcher proposes.