What is the mechanism that prevents microevolution to become macroevolution?

I have no idea why Cheetahs are such a popular creationist pick. They are living proof of how fragile a species becomes when evolution is halted by an extreme population bottleneck, resulting in a limited gene pool. African Cheetah population was only reduced to hundreds. Taking this to the next level the tiny gene pool
caused by God's flood would make us all a lot less diverse than cheetahs (or more likely dead). Interestingly the cheetah population of today has
an exceptionally high mutation rate. Evolutions reaction against a shallow gene pool???? (don't attack that last bit it's just a personal hypothesis).PS. Who ever heard of evolutionist physics or geology, I've always wondered why Creationists tend to call any opponents Evo's, i.e. if you're going to challenge every field of science at once why not be forthcoming about it.Edited by qed, : fact checking

Ok i did 2/3rds of a BSc in Mol Bio before i ran off to business school these are off the top of my head and pretty basic but i hope it helps clear up some of the communication difficulties here.Genotype: what the dna in your sex cells says / heritable DNA.Phenotype: What you look like, in Genetics this term is usually used to describe the physical expression of you genes disregarding environmental factors.The (most) inportant difference: Genotype contains recessive* or unexpressed information which may not appear for many generations.Introns: DNA of debated/unknown/no purpose cut out during rna production. Eukaryotes have them everywhere, Prokayotes only in transport and ribosomal rna coding DNA.Allele: A chunk of dna responsible for ....Divergence: The gradual seperation of a species into two non-interbreeding species.Mutation (Evo): Change in genotype caused by an error in transcription or random interaction with oxidisers or radiation. Humans contain 120 on average.Beneficial Mutation (Creationist): Mutation which provides a species with an observable new characteristic which helps it to reproduce.Neutral Mutation (Creationist): most (much greater than 99.9%) of mutations fall into this catergory, mutation of no significant observable effect.Detrimental Mutation (Creationist): Mutation which provides a species with an observable new characteristic which hinders it's reproduction.The above are also Darwinist concepts however NeoDarwinism considers
all mutations to contribute to diversity provided they allow future reproduction. Diversity = greater chance of survival.Devolution (Creationist): Reduction in the potential / ability / genetic information of a creature due to evolutionary mechanisms.Devolution (Evo): A subset of evolution defined by semantics.Junk DNA: Ok popular science has hijacked this term leading to a heap of confusion, when Eukaryote non-sex cellular dna is replicated the last chunk of the chromosome is not copied, theres a bunch of useless
DNA tagged onto the end and this gets slowly lopped off with each new
generation of cellular division. Prokaryiotes do not have this problem
(easy to work out why if u think about it). Pop science and even wiki use this term for all dna of unknown function, i think it's confusing and caused by the catchiness of the phrase.Just thought i'd put that that here*reccessive/dominant PHENOTYPES are not strictly accurate but work for most purposes.Edited by qed, : more stuff

Cheers for that, you're quite right. Though some of the definitions "divergence" in particular were aimed at following the precedent set in this thread."Devolution" is a Creationist conception, you'll struggle to find it in any reputable journal. I ventured a guess based on Sciam's "Answers to Creationist nonsense" article. The main point is that Neodarwinism does not judge one form of creature to be better than another thus "Devolution" is meaningless.The "Junk DNA" rant was pulled straight from the ramblings of my Genetics lecturer, i don't have the time or energy to track down a nickname but i don't think it matters so long as telomeres and introns are not confused as they seem to have been earlier in this thread.
How about 'TOE TAGs' for a new pet name? Edited by qed, : No reason given.