Water Bears Are the Master DNA Thieves of the Animal World
 
Foreign genes from bacteria, fungi and plants may have bestowed these animals with their ability to tolerate boiling, freezing and the vacuum of space

A dried-out tardigrade can be reanimated just by adding water—even decades later. They’re found on every continent including Antarctica, and they live in environments ranging from the deepest ocean trenches to the hottest deserts to the tops of the Himalaya. 
Now scientists have discovered that tardigrades possess yet another extreme claim to fame: Their genome contains the most foreign DNA of any animal species known.
Rather than inheriting all of their genes from their ancestors, tardigrades get a whopping one-sixth of their genetic makeup from unrelated plants, bacteria, fungi and archaeans, researchers report today in PNAS. The bizarre mashup highlights the fact that species can take shape in much less linear ways that commonly imagined.

‘When most people think of the diversity of life and flow of genetic information, they picture a tree with big branches generating smaller ones, but without any connection between the limbs,’ says study leader Thomas Boothby, a Life Sciences Research Foundation postdoctoral fellow at the University of North Carolina, Chapel Hill. ‘We’re beginning to realize that instead of the tree of life, it might be more appropriate to think of the web of life.’ (source smithsonianmag.com) more >>