[Right Wing Professor]

Volvox evolution: there are whole books written about it. Alas, I haven't read them:

David L. Kirk
VOLVOX, Molecular-Genetic Origins of Multicellularity and Cellular Differentiation

There's also this and this. I have access to the second article; I'll read it and post a summary in the next few days.

[Tribune7]

OK, thanks. If anything can show evolution from a single cell to multi-cell it will be Volvox.

[Elsie]

Therefore, the central premise of this book is that Volvox and its relatives provide us a unique window through which to examine the important roles that a few regulatory genes can play in both development and evolution, and gain fresh insights into a problem that has fascinated both developmental and evolutionary biologists for many generations: How do multicellular organisms with differentiated cell types arise from unicellular antecedents?

Indeed!