An Evolving Analogy: Part 3, Convergent Evolution and Mimicry

StevenSimske — Fri, 17 Oct 2008 05:10:00 GMT

Change isn’t always for the better. You can, for example, be short-changed. You can change from bad to worse. You can change your Outlook (Microsoft or otherwise). Or you can change a diaper (well, this is better, presumably, for the wearer of the diaper). Even in evolution, change is not for the “better”. Change simply is a consequence of genetic variability implicit in meiosis, mutation and mistakes innate to the reproductive processes.

Our interpretation of genetic change, therefore, depends on the perspective from which we view the change. As I discuss convergent evolution and mimicry in this posting, then, please keep in mind that usually one partner in the convergence/mimicry benefits more than the other.

Convergent evolution and mimicry are two of the most powerful concepts in evolution, as they directly relate to the change wrought by evolution. Since security printing and imaging, and the related supply chain and brand protection issues it addresses, must evolve as technology evolves, I consider these concepts as Part Three of the “evolution analogy” series.

Convergent evolution is the term for analogous structures that arise in genetically unrelated species as a consequence of their environment selecting a similar role for both species. This is different from a homologous structure, which arises in genetically related species. Examples of convergent evolution include:

1. Koalas and humans have independently evolved fingerprints

2. Bats and birds have independently evolved flight

3. Bats and toothed whales have independently evolved sonar-like capabilities

4. Opossums and humans have independently evolved opposable thumbs (pandas, too, although their thumbs are actually extensions of their wrist bones)

Examples of homologous structures are even more plentiful, including:

1. Robins and sparrows can both fly

2. Chimpanzees and humans both can walk

3. Giraffes and seals each have 7 vertebrae in their necks

4. Garter snakes and pythons each can slither

In security printing and imaging, these terms can refer to printed deterrents (homologous structures) and printed vs. non-printed deterrents (analogous structures, or convergent evolution). Security printing is the use of digital variable data printing (VDP) to add information to printed material. Bar codes contain bits of data suitable for disambiguating one item for sale from another item for sale. 1D and 2D bar codes contain different densities of data (number of bits per given area), but may contain the same (point-of-sale, track and trace, etc.) data. Thus, they are homologous (related and having similar utility).

Homology extends to any printed information that can be read and translated; that is, decoded from an image. So, printed features such as color tiles, guilloches, copy-detection patterns, watermarks, and their kin, are homologous—each is a species of the genus “security deterrent”.

Convergent evolution of security printing and RFID, however, is perhaps of more interest. Will all RFID tags be printed with electromagnetic ink (metallic or organically based, for example) someday, and RFID printing simply be incorporated as part of the printing-as-manufacturing process? Or will RFID manufacture move toward nominal cost along another route, and so reduce the importance of printed features in security? If the former, then the current convergence of utility of RFID and security printing may become an irrelevant distinction—that is, RFID will effectively become “extinct” and become simply a part of printing. Or, conversely, security printing will effectively become “extinct” as RFID assumes the roles of unique identifier, copy-prevention and tamper-evidence.

It seems more likely, though, that we will continue to reasonably view RFID and security printing as two separate species. Two species that are, in some respects, are undergoing convergent evolution. RFID is being extended to include tamper-evident information, using features such as what I term “RFID apoptosis” (programmed suicide possible with “KILL” and related RFID features) and signed additional bit strings. RFID is also, increasingly, being used for additional informational purposes, such as RFID-enable hardware in everything from car tires to refrigerators. Security printing, meanwhile, banking on the innate and broad adaptability afforded by digital VDP (variable data printing), has long been able to provide functionality like that of RFID. Bar codes provide EPCglobal or other mass serialized unique identifiers. VDP lends itself to an inference model based on either pre-printed serialization or inline serialization with real-time inspection. All security printing is missing is non-line of sight reading, although the development of conductive and other metallic inks indicates this hurdle will also soon be overcome.

Interestingly, RFID and security printing continue to “radiate” in terms of their phenotypic utilities, even while converging with respect to each other. This is easier to understand when one considers that they are converging to the same logical set of utilities: track and trace, authentication, point-of-sale, inventory management and forensics.

We come to Batesian mimicry, which is different from convergent evolution. Batesian mimicry can be simply described by example: The “classic” Batesian evolution is when uncommon, tasty animals resemble abundant, foul-smelling/noxious animals. Think of the yummy little bug that looks so much like a nasty tasting bug. Monarch butterflies and wasps have plenty of Batesian mimics out there.

Batesian mimicry also has an analogy for security printing and imaging. Security VDP affords the brand owner the ability to print a surfeit of security features, some overt and some covert. Some of these are tracked (inspected, authenticated, used for track and trace), and some are not. Those that are not, as I’ve noted in past blogs, can be used as “decoys” to get counterfeiters to try to mimic. They can also be used solely for forensic analysis of the counterfeiters, in which case they are not just decoys, but also bait. So, these excess deterrents are Batesian mimics of the tracked deterrents, and your would-be counterfeiter, in an effort to capture all the legitimate deterrents, will also swallow a number of Batesian mimics. The key is that at least one of the security VDP deterrents does in fact leave a bad taste in the counterfeiter’s mouth!

-Steve

Security Printing and Imaging : RFID, Pre-adaptation, Batesian Mimicry

An Evolving Analogy: Part 3, Convergent Evolution and Mimicry