Single Cells Evolve Large Multicellular Forms in Just Two Years

[Rumraket (Mikkel R.)]

@thoughtful

I’m not saying it’s not an evolutionary process. I guess I’m asking why a new phenotype in a unicellular organism (occuring because of mutation and selection) is cellular differentiation and not just a new phenotype.

You’re not asking a bad question, it’s just that the answer is fundamentally arbitrary. This gets at what exactly we mean by differentiation.
This is usually taken to mean different cells that make up a larger whole take on a more specialized role depending on where in this larger structure they are found.

This is one of those cases where no matter where you put the line it’s going to be pretty much completely arbitrary. And I’m relying on that for my argument. That because it is fundamentally arbitrary where we put the line and say “this now counts as differentiation”, it seems to me that in so far as any two genetically identical cells are different from each other in how they express their genes, then we can consider them to be by definition differentiated, and that it is only a matter of degree that separates more well-recognized cell-specializations(skin cells vs neurons, for example) from each other.
Thus if anyone is going to disagree with me and say we should not count the cells on the outside of the snowflake yeast as being “differentiated” from the cells in the core of the snowflake yeast, I have to ask why not? What makes one degree of difference objectively better fitting for “differentiated” than another?

@thoughtful

What I was looking up yesterday was suggesting cell differentiation in multicellular organisms uses epigenetics.

Yes, that’s common knowledge.

@thoughtful

I know nothing about that, but shouldn’t some evidence of that be shown before a case can be made?

Evidence of what?

[Marty]

@Rumraket

This is one of those cases where no matter where you put the line it’s going to be pretty much completely arbitrary. And I’m relying on that for my argument.

Very fair comment. Let me try to characterize it a little differently.

There’s this very long ladder of changes leading to obvious “differentiation.” We don’t know how many steps there are on this ladder, and we don’t know how big the steps are between the rungs, but I have faith that this is an example of the first step. And since I am an atheist and believe all of life traversed this entire ladder on its own, I’m going to put the burden of proof on you to come up with an explanation as to why it is NOT differentiation.

Honestly asking, is that unfair? That’s what it looks like to me. And that’s not necessarily wrong, it’s just that others may not agree with you and may not feel the need to have the burden of proof shifted to them for disagreeing with the claim.