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It's a fair question... ...to a point.
Creationists often state that information cannot be added through natural selection. If it were true, it would certainly be a problem for evolution.
You'll recall the huge bibliography I posted a few weeks ago, of articles that explain precisely how information can be added and documented examples of it happening in a lab..?
As for switching, genes are switched on and off all the time. For example, the on set of puberty is controlled by a gene being switched on. However, 80-90% of all our DNA doesn't do anything - it's switched off, doesn't encode proteins or it's just meaningless. If you've got a working sequence of DNA but which is switched off, all it takes to switch it on, is the right mutation.
Slow worms are limbless lizards, China. Maybe that's what you're thinking of?