Feature

  1. Brains in Dreamland

    Sigmund Freud's century-old dream theory gets a contrasting reception from two current neuroscientific accounts of how and why the brain generates dreams.

    By Bruce Bower
  2. Health & Medicine

    Ancient Estrogen

    A jawless fish ancestor may have revealed the most ancient of hormones and how current hormones evolved from it.

    By Jessa Netting
  3. Tech

    Soaking Up Rays

    Although light shines through body parts of a primitive marine sponge much as it does through sophisticated optical fibers for telecommunications, scientists differ on whether sponges hold clues to better fibers for humankind.

    By Peter Weiss
  4. Health & Medicine

    Busting the Gut Busters

    Scientists are uncovering a cache of specialized weaponry used by bacteria that can spear holes in the intestine, perforate it, force it to change shape, and then spew toxins that attack other organs.