"Degeneration = fixity" Fascinating. And bizarrely wrong.
Degeneration and fixity are mutually exclusive concepts. If a species is degenerating then it is not fixed. Look, Linneaus discovered species hybridization over 200 years ago and realized that his species concept did not equal biblical 'kinds.' So your caricature of creationists believing in fixity of species has been out of date literally for centuries. I don't doubt that you can find some grandma somewhere who believes in fixity of species, but what would you say if I started depicting Lamarckism as the latest and greatest in evolutionary theorizing?
The real issue is whether life is on an 'upwards' path of increasing functional complexity and organization and functional diversification, or are we degenerating. The overwhelming evidence of empirical evolutionary biology testifies to the latter, as documented in books like Genetic Entropy by Dr. John Sanford and Not A Chance! by Dr. Lee Spetner. Against the caricature of "change vs. stasis" we have the real issue of "degeneration vs. evolution". It's not wonder evolutionists simply refuse to address the evidence on these terms.
IF mutations ONLY lead to "degeneration" or "corruption" (as the YEC claim), then there is NO viable mechanism for "differentiation". The YEC's claim of "degeneration" implies fixity. It's not my fault that it's nonsense.