Water molecules are popular because the

This is because the electrons are up around the oxygen more than they are around the hydrogen. The electrons are spinning around but they're around the oxygen more than they are around the hydrogen. This makes them polar because they have a charge on one end of the molecule. In a nonpolar molecule electrons are evenly distributed.

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.