Reducing organisms to genotypes and species

How is the study of your ancestors biopolitical, not just biological? Does that make it less scientific or differently scientific? What was gained by reducing organisms to genotypes and species to gene pools? What is gained by reintroducing bodies and species into evolutionary studies? The molecular biologist François Jacob argued that evolution is more like a tinkerer than like an engineer. In what ways do we seem like precisely engineered machinery, and in what ways do we seem like jerry-rigged or improvised contraptions?