Yesterday’s article in Wired about genetically modified mice with superior aerobic exercise capacity sparked a thought from Elise today – could a naturally occuring virus have a similar effect? The link between viruses and some disorders, such as the relationship between HPV and cervical cancer in women, is well established. I suppose it’s also possible that a virus could have a beneficial effect, though such a thing would be rarer than a detrimental effect. I’d expect an essentially random change caused by a virus to have more of a chance disrupting a human system than enhancing it.