Creationists accept "micro" evolution but not "macro" evolution. Tell me, creationist?

is your proposed mechanism to prevent accumulated changes of "micro" evolution (your term, not modern science's) becoming "macro" evolution?

Which undiscovered (by science) mechanism prevents evolution leading to speciation?
Update: Dawn: Wrong. Genomes tend to get bigger, not smaller, because of a number of mechanisms including duplications, retro- and pararetroviruses, transposons, polyploidy. Ask your pastor to clarify these terms for you... Haha
Update 2: David: I hope you were being ironic or something. Otherwise your response is a huge steaming pile of uninformed you-know-what
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