Comment Re:Theta Polymerase (Score 1) 603
Yes. As I noted, the research is very young on this. We don't know yet how the cell knows which RNA to convert back into DNA. We don't know yet what protections are in place to prevent the undesired introduction of foreign RNA into the human genome. There will undoubtedly be some mechanism that handles both of these. There will also undoubtedly be some scenarios when these fail. From the study itself, we know that the theta polymerase is more active in cancerous cells than non-cancerous cells. We don't yet know if that is a cause or an effect, but it is possible that there is a connection between the failure of the safety mechanism and the incidence of cancer.
Along these lines, there is some compelling evidence for the lateral transfer of DNA between species in higher organisms, something that until recently was thought impossible.
https://www.quantamagazine.org...
We simply don't know a lot of the details about how these things work. So, showing a little humility about our assumptions goes a long way. For example. Linus's assertion that RNA introduced into the human body can never be turned into DNA that is incorporated into the nucleus of a human cell is an assumption that cannot be backed up by any scientific study of which I am aware. And, given what we now know about the topic, and a familiarity with the history of research into DNA, it is likely that when we do study this closely, the answer to the question will end being one of how often it happens (likely fairly rare, but perhaps more common as we age) versus it never happening at all.