It is very interesting. I wonder, however, if it&#x27;s enough to isolate all relevant variables (this is peanut gallery speculation, I am not a scientist of any stripe)? The narrator explains that she is &quot;an accident &amp; emergency doctor [...]. Rushing around on my feet all day with strange working patterns&quot;. Never mind that the stress and adrenaline of such work must affect her body in some ways, she probably also moves quite a bit more than the average person. We&#x27;re not told anything about her counterpart than her name, and that she&#x27;s the same age and gender.