This is a calculated trick to get schoolchildren to swallow - not so much snails - but rather, the evolutionary hypothesis.
Snails are born with varieties in colour BUT never beyond their own genetic parameters.
It does not matter one whit how many variations are found - this is NOT evidence of evolution.
Remember: wolves, great danes, dachsunds, poms and labradors are all from within the genetic parameters of their group. Few scientists would claim this to be evolution - so why make so much of coloration in gastropods?
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