If somatic mutations are common in healthy bodies, then biomedical researchers can no longer assume that DNA aberrations point toward the causes of disease. Doctors won’t be able to trust that the DNA found in a blood or saliva sample actually reflects the gene sequences in the heart or the liver. Should somatic variation turn out to be not just common but also good for you, it will undermine the longstanding presumption that the healthiest genome gets replicated with perfect fidelity. The most highly functional bodies may be the ones that permit a little mutation, that encourage a certain amount of genetic wildness and disorder within
not only are you 90% bacterial, but the human parts of you can’t get their shit together.
within our bodies our cells are not all created equal at the genomic level. In other words, we are mosaics.