[Frumious Bandersnatch]

I've never seen a working statement of this anywhere, except from Creationists and ID'ers. I know what you're trying to say (I think), but if you start with biofilms and anything at all happens, you're bound to get something more capable than slime. (I had to work the "slime" angle in.)

It is not generally said, but it is heavily implied, and is, in fact assumed generally by evolutionists.  If you don't believe me, just take a look sometime at any chart showing the evolving of Homo-Sapiens.  And this is just one example (charts of almost any type of animal shows the same).  Yeah, and apparently procreation is not necessarily a good indicator of speciation.  I've heard of cases where cross-species pollination has occured.

As far as the slime is concerned, would that also involve those leaving trails of pre-biotic matter in their wake?

[<1/1,000,000th%]

It is not generally said, but it is heavily implied, and is, in fact assumed generally by evolutionists.

Now that you mention it, I should say that I've heard it said by high school science teachers as well. The folks I work with don't hold that viewpoint. They're mainly PhD's and BS'ers.

As far as the slime is concerned, would that also involve those leaving trails of pre-biotic matter in their wake?

I leave plenty of organic molecules in rest rooms, if that's what you mean. Pre-biotic is a whole another discussion that may, or may not, include prions, viruses and some other stuff that I'm not sure has been formally named yet. The term generally used around here is "crud" or "goop".