“First, we have to get rid of the idea that one gene codes for one protein. The genome is highly complex and often contains information in at least four overlapping dimensions. Changes in one dimension in the genome will affect the other three dimensions. This makes it impossible for evolution to occur. Humans have about 23,000 genes (I am using the word ‘gene’ loosely), but they are able to produce ~200,000 proteins. Why? One reason is that the genome is designed with instructions to splice and rearrange the same stretch of DNA to produce a vast array of different proteins. How could we speak of a ‘leg’ gene, if the same stretch of DNA is also used to code for many other things? Humans have no “leg genes”. Do we say that whales have leg genes if it matches a somewhat similar-looking stretch of DNA in humans that does something in legs? What if that stretch of DNA is not used for legs in whales but is there for a completely different function in whales?
Read more here: https://creation.com/whales-and-leg-genes