The characteristics of RNA in the modern cell that suggest that RNA may have an ancient role metabolism are? Why is the gene for small-subunit RNA(16S RNA) particularly suited for the study of the ancient phylogeny of living things.(three reasons). Why does the gene while useful studying the phylogeny of life, is not useful for studying the phylogeny of mammals. why? A common objection to genetically modified food, and genetic engineering in general, is that is “not natural of genes to cross the species barrier” comment on whether this argument is logically sound.