Why is biochemical evidence of evolution considered to be indirect??
Since you said “evidence of evolution” and not “evidence for the theory of evolution”, then I have to assume you are just asking for evidence that evolution has occurred in a particular instance. Evolution is defined as “the change in allele frequency in a population.” The biochemical evidence (the proteins) is indirect evidence of the specific allele (the coding of the gene). So if you have brown eyes, that is indirect evidence that you have the allele (the gene) for brown eyes. So if 58% of a population has brown eyes, that is indirect evidence that 58% of the population has the allele for brown eyes. So if the frequency of brown eyes goes up from 58% to 63% after 10 generations, that is indirect evidence that the allele frequency has changed from 58% to 63% … in other words, that is indirect evidence that evolution (change in allele frequency) has occurred. It sounds kinda odd to say that the presence of a protein is “indirect” evidence of the allele (the gene) that codes for that
