Can Single Cell Organisms Evolve into Multi-Cellular Ones?

I was early in my carreer as a creationist aware that multicellular organisms mean specialised cells within same body.

Single Cell organisms mean all the cells are the same, and moreoever, it means multiplication by division, whereas many-celled organisms mean that a one cell starts off from two very specalised cells, which come from a body with specialised cells - in other words, sexual reproduction.

Today I learned of yet another unbridgeable gap for Evolutionists to bridge between one-celled [habitually, not just moment after conception, one-celled] ancestors (or supposed such) and Multi-Cellular progeny (or supposed such).

H/T to Shaun Doyle, here I link:

CMI : Serial cell differentiation: intricate system of design
by Shaun Doyle
http://creation.com/serial-cell-differentiation-intricate-system-of-design