The Answer to Another Question of the Ages

How we descended from sponge larvae.

After having considered for 30 years the steps in the evolution of multicellularity and bilateral symmetry, and never having felt that I more than vaguely understood the outline, this finally smells right. It is so simple once you see the explanation. (See Reading Maya below.)

http://www.newscientist.com/article/mg20227061.300-sponge-larvae-your-unlikely-ancestors.html?full=true

In particular, see these diagrams.

http://www.newscientist.com/gallery/mg20227061300-sponge-larvae-your-unlikely-ancestors