Can you hold your breath forever?

(PhysOrg.com) -- Oxygen may not be the staple of modern complex life that scientists once thought. Until now, the only life forms known to live exclusively in anoxic conditions were viruses, bacteria and Archaea. But in a new study, scientists have discovered three new multicellular marine species that appear to have never lived in aerobic conditions, and never metabolized oxygen.

Why'd the chicken cross the road? Cause it saw the light was green

• Color receptor organization in the retina chickens exceeds that of mammals and most other retinas observed in nature.
• But why is that? One explanation:
• Millions of years ago, during the evolution of birds and mammals, our ancestors were primarily nocturnal, adapting night-vision receptors called rods for survival from the threat of larger predators.
• Birds on the other hand, widely believed to be descendants of dinosaurs, were able to survive during the daytime and further develop their light-sensing receptors called cones.
• Humans have retina cones sensitive only to red, blue, and green wavelengths.
• Birds share these and have other receptors to detect violet and ultraviolet (UV) wavelengths, and another specialized receptor believed to detect motion.
• Relevance:
• Could lead to new understandings of inherent problems in human eyes and ideas on how to fix them.

http://www.physorg.com/news185539169.html