[dark_lord]

Your original request for a falsification of common descent has morphed into your current argument that we cannot assume mutations are responsible for driving evolution.

Actually, all I said was: 'Regarding the claim that "all life on earth is descended from one (or very few) common ancestor(s)" -- how is that falsifiable?' Your response has been roughly "well, the DNA is related, ergo they have only one (or few) common ancestors." The counter to that is that it may well be turtles all the way down, if you get the allusion.

It is safe to assume that the phenotypic differences between organisms is due to mutation.

That is the point. You assert it is safe to assume that. I assert there is a lack of proof, and therefore it is not safe to assume that.

[RightWingNilla]

Your response has been roughly "well, the DNA is related, ergo they have only one (or few) common ancestors."

No no no!

I said if the DNA between all oragnisms differed, then it would falsify common descent. I did not set out to prove common descent, only to establish a criterion to falsify it. Do you not see the difference?

You assert it is safe to assume that.

Yes, and then I provided you evidence for my assertions. Not "proof" mind you, but evidence. And I have plenty more where that one example came from.