Viruses in the Genome

Years ago - I wish I could find it - a paper by Brian Kernighan talked about the theory of computer virus code. This was in the very early days. He pointed out that the ultimate point of vulnerability was in the opcode generation code of the compiler. Malicious code embedded there would be difficult to detect except by an examination that very few people could make. Since the compiler is used to create, not only the operating system itself, but future versions of the compiler, this code would be ultimately be embedded in the very genome of the operating system itself.

Now fast forward (or even rewind a few millenia).

This article in Discover Magazine, The Insanity Virus describes viral code that is embedded in our very DNA. How did it get there?

Sixty million years ago, a lemurlike animal—an early ancestor of humans and monkeys—contracted an infection. It may not have made the lemur ill, but the retrovirus spread into the animal’s testes (or perhaps its ovaries), and once there, it struck the jackpot: It slipped inside one of the rare germ line cells that produce sperm and eggs. When the lemur reproduced, that retrovirus rode into the next generation aboard the lucky sperm and then moved on from generation to generation, nestled in the DNA. “It’s a rare, random event,” says Robert Belshaw, an evolutionary biologist at the University of Oxford in England. “Over the last 100 million years, there have been only maybe 50 times when a retrovirus has gotten into our genome and proliferated.”

It seems that Professor Kernighan's thinking was not so original after all. Nature was way ahead of him. This viral code is embedded in the compilers - the cells that produce sperm and eggs - and ensure that the DNA they carry also includes code to embed the sequence into the next generation.

The original article is about how one of these viruses, that we all carry might, under certain circumstances, be the cause or trigger for a wide range of mental illnesses. That is really interesting as well, but not so profound (at least to me) as the idea of infecting the compiler happening in nature.