A barrier to macroevolution & objections to it

That's not an argument, though. That's a weasel phrase. No matter how many mutations we show you, you can always argue that it's "not enough."Why don't you pick a number? How many mutations per generation are required to keep up with selection, etc.?

Well, are there enough, or aren't there? If you didn't mean to say there weren't enough, then why did you say there weren't enough? If you have an objection to the bacteria studies, you certainly haven't told anybody what it is. Until such time as you're able to express exactly why bacterial studies, long used as model organisms for the study of genetics, are somehow invalid here, they constitute a large line of evidence that you've simply chosen not to address - to pretend like it doesn't even exist, in fact. Losses don't bring about new traits. Something is not new simply because it is what is left over.If I have a full refrigerator, and I throw out all the fresh fruits and vegetables and simply mix together two containers-worth of leftovers, I have not made a new meal. We're still eating leftovers.New alleles are required for new traits, because over enough time, given a constant number of alleles, all possible allelic sexual combinations are eventually expressed. Simple statistics. You eventually get every possible phenotype just at random, so reducing alleles doesn't get you anything new. Maybe it gets you more of something, maybe less, but neither of those are new.Genuinely new traits require genuinely new alleles, and mutation is the source of new alleles. How are you ever going to figure out what that article says if you immediately reject any explanation of it that appears to support evolution? If you're waiting around for someone to explain it to you in a way that undercuts evolution, you're going to be waiting a long time. Evolution is accepted by scientists because the evidence supports it, so when evidence is presented for it, you're simply not going to find a way, except fallaciously or dishonestly, to use that evidence against evolution.

Traits that hitherto have not been present in the population. Says you, but that's a statement contrary to both logic and evidence. And you seem to be forgetting the most basic principles of Mendel; namely, that traits as often as not are discreet, independantly-variable aspects controlled at a single genetic locus, not the result of any kind of genetic "mixing." A few traits exhibit that sort of behavior, but many more do not."New" is not the same as "left over." Reduction in alleles cannot be the source of truly new traits. And truly new traits are required to explain the diversity of life on Earth in the present and past.

We don't need to assume diversity; we can observe it and measure it. Any disagreement creationists may have in regards to the amount of diversity is simply their refusal, once again, to admit the existence of any fact they find inconvinient to their ideology.

I don't understand why you believe this to be the case. It's well-known that the theory of evolution explains the diversity of life on Earth as the result of random mutation and natural selection.Why would the theory of evolution be required to support something it doesn't state?

I don't see a significant phenotypic diversity among dogs. I see a continuous distribution of traits along a fairly small number of attributes.I mean, to even suggest that these constrained gamuts represent "vast morphological change" would seem to undercut the YEC contention that animals vary only narrowly within their "kind."