If there is one word that the life sciences view with suspicion, it is “dogma”. It is supposed to be a universal and indisputable truth, a principle on which there can be no compromise. This is because there are always exceptions to even the most golden of rules, and any biologist knows dozens of them. So when you hear, in a genetics lecture, that there is a “central dogma of biology”, the suspicion that something is amiss immediately arises. First “proclaimed” by Francis Crick – the discoverer of the structure of DNA – this dogma states that information, once it has left the molecules containing the cell’s “instructions for use”, namely the nucleic acids DNA and RNA, cannot go back. The transfer can only occur between nucleic acids and nucleic acids, or between nucleic acids and proteins, but never from proteins to DNA, which is present in the nucleus. The genetic heritage appears to be a sort of inner sanctum inaccessible to external information, which, above all, does not change as a result of what happens during life. It would seem to be a system offering an excellent level of information protection. If every cell were to do as much as it pleased and modify its genome according to environmental conditions or other influences, the risks of improper modifications would be extremely high.
