Whether a gene is 'highly conserved' or not is an artifact of the initial assumption, that of naturalism and therefore common descent.
That there are functional reasons for similarities is trivially obvious, without an appeal to 'conservation'.
*Any* genealogical 'pattern' is acceptable, hence 'birds and crocodiles' or 'humans, chickens and puffer fish' is perfectly fine, though patently absurd.
A common designer explains the data much better, without appeal to absurd statements like 'birds and crocodiles share a common ancestor'. Evolution fails based on the extreme credulity necessary to accept the conclusions that are the result of the primary premise (that of naturalism).
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