The oldest examples of signing something are non-western. We know of several Sui and Tang dynasty paintings which were known to be by specific individual artists although the question of signature is complicated by the fact that most of these survive only in later copies. Decipherment of Mayan hieroglyphics has revealed that a number of Late Classic Mayan vessels were signed and in a few cases, we have even been able to reconstruct the signatures of various artists. In the Western Middle Ages, it is of interest to note that you do have some signed artworks, but that many of these are large public commissions with extremely visible signatures and even into the early modern period artists could be wildly inconsistent about signing their own work. To the degree we can make useful generalizations, artist signature's start happening when the artist A) had a specific reason to publicize the involvement in a particular work whether to publicize his involvement in a major civic project, to claim an artwork as his own in a specific exchange system or because he or she knows people will care about who made the artwork they are buying and B) is of high enough social standing for anyone to care about this. A "smaller' painter, for instance, might not have much reason to sign their work and a major painter doing basically minor work might likewise lack a reason to sign their work, whereas a highly trained and esteemed painter of has every reason to stake a claim to a well-done piece of work. The story of signature and authorship is connected to the history of humankind and various stages of social organization and economic systems we went through.

In biology, we have different kinds of distinction. One of the unique traits of humans and other primates are fingerprints.

The DNA is, even more, a unique signature. We share 60% of our DNA code with tomato (tomato has 7,000 more genes than a human being!) and 99% with chimpanzees, still, there are no two other humans that have the same genetic code. (In 1984 Professor Alec Jeffreys discovered the variations in DNA, unique to each individual.)   I was thinking about how biodesign and designing biological entities would change our approach to genetic code. Maybe we would like to claim our authorship and sign our creations in the language of the nucleotides? We do that currently through procreation but in the future, it might look quite different. That is why I synthesized DNA strands with my name encoded in it. 

I was thinking later about kinships and wondering are there any existing currently organisms with my name inscribed in their DNA. That is why I compared my synthesized name with the codes of so far catalogued organisms. It showed that my name is closest to part of the DNA of bacteria Shewanella psychrophila.  This is very interesting bacteria lives in the deep-sea sediment and one of its strains is investigated for the possibility of generating electric current. Shewanella consists of facultatively anaerobic Gram-negative rods, most of which are found in extreme aquatic habitats where the temperature is very low and the pressure is very high.