I believe I already answered you. Life may be divided by separate ancestry. That part is not complicated at all. Could or could not the origin of separate ancestral groups create actual boundaries between life?
Life certainly diverges and evolves along separate lineages. But that doesn't mean those lineages don't share common ancestry.
That is the claim I'm trying to get after: if there is a way of demonstrating that these lineages
do not share common ancestry (e.g. some sort of biological disconnect).
No more odd than your inability to identify an actual (not hypothesized) morphological/molecular gradation between any major animal groups. Just gaps in the theory, right? Science is still working on it.
Not sure what you mean by "actual". If you're asking for 100% perfect information, science can't provide that.
That said, all of the available evidence does point to shared ancestry and not independent creation. If you want to argue independent creation
and want to argue that there are biological limits to evolution whereby organisms cannot share ancestry, then you need to demonstrate that. Simply trying to flip this around and make it all about evolution isn't going to help you here. A negative argument against evolution is not a positive argument for creation.
From what I understand, there's been plenty of creationist arguments and proposals for likely division of kinds based on animal characteristics. (such as baraminology) Can they demonstrate ironclad proof that these are indeed the original kinds? No, it's just a theory.
I'm aware of creationist attempts to classify organisms as "kinds". I'm also aware that they don't have any sort of consistent definition for classifying organisms as such; which is why I think every creationist on these forums has their own private definition.
Creationists must always demonstrate airtight, ironclad proof for everything, and their reasoning or hypotheses are disregarded as irrelevant.
This is false. I've never demanded this level of standard from creationists. What I am demanding is
something other than baseless claims that there are biological barriers to evolution.I don't care if it's purely hypothetical, at least present something tangible for discussion.
If there is a biological barrier preventing evolution beyond a certain degree of change then what is it? If you want to argue that there are discontinuities in biology indicating separately created life forms, then where are they?
Put something on the table.