Once again, I admire your honesty on these issues. Go to my web page and download the cambrial explosion computer program. The first generation screen critters in that program have the same genetic code. As you will see, the explosion of forms occurs within about 4 generations. This is a phenomenon of nonlinear dynamics.
Life is a nonlinear system.
Small changes to certain places in the DNA create large morphological effect. From that point on, small changes began to have rapid and large morphological change. That's my point with the blue-green algae. My understanding is that algae does not have to be single isolated cells. That is clearly impossible with today's technology.