When I think about models of evolution, I’m reminded of an episode of a cartoon show, “I am Weasel,” called I.M. Diety. Forgive me for taking us back to 1998, but the premise of this episode is that the super-genius main character, Weasel, and his nincompoop of a friend, Baboon, purchase these “instant life” packets which require the addition of DNA (spit) to grow your own society in a petri dish. It’s kind of like a chia pet, except you’re growing living beings.

To summarize, they watch life evolve on a petri dish from its earliest form all the way through advanced civilizations that worship them as “the gods in the sky.” The denizens of these science experiments are unaware of anything outside of the walls of their petri dish. Eventually, Weasel’s society develops sophisticated technology and flies to Baboons society. Intermixing of the species is cataclysmic and the experiment is over.

Evolution in a petri dish.

I am still amazed at how vivid my memory of this episode is. The really cool science aspect was that they simulated evolution in vitro. Directed evolution is a relatively common biological technique. For instance, when dealing with a normal strain of E. coli, if we wished to “create” a strain that is resistant to penicillin, we would simply plate some E. coli on penicillin infused culture media . While 99.99% of the E.coli would die from the penicillin, the remaining 0.01% will survive due to having received random mutations that conferred resistance to the compound. This can be viewed as evolution in vitro.

The dramatized, yet cool aspect of the “I am Weasel” episode is that highly complex life forms developed overnight. For organisms that we are familiar with to radically evolve in such a short period would be very unlikely (I have become accustomed to avoiding the word impossible). The main reason for such improbability is the long generational periods. A very large number of generations and different selection factors contributed to evolution on earth, and to replicate these results should take just as long!

While in vitro models of evolution might have us waiting forever, in silico models of evolution have already proven to be very worthy of consideration. Life forms on earth compete for resources in order to survive and reproduce. At the fundamental level, it is the perpetuation of a given sequence of DNA that drives animal instinct (even human beings): or so would argue those who believe in Dawkins’ Selfish Gene. With this in mind, we have identified some variables: resources, competitive ability, and reproductive ability. We have also identified DNA as giving the instructions on how to compete for these resources in order to reproduce. Adaptation occurs via mutation.

Moving from in vitro to in silico.

To create in silico models, these aspects of evolution had to be mapped to their computer counterparts. DNA can be substituted for by self replicating computer code that undergoes changes/rearrangement. Resources can be simulated by computer memory or RAM. The actions of competing and reproducing are executed by self-replicating code as they compete to take up more of the computer’s memory.

This is more or less what Thomas S. Ray created in Tierra, his model of artificial life developed in the early 1990s. In Tierra, strings of computer code compete for CPU time and computer memory by copying themselves with some rate of mutation. Ray’s program simulated a host-parasite battle where hosts were infected by parasites, and over time, it was seen that hosts developed immunity to the parasites in an evolutionary arms race occurring in silico.

Who is God of the Computer Realm?

In silico models of evolution are great because they allow for many generations to occur within a short period of time. The digital organisms being created by these investigators evolve and mutate just like biological organisms. While computer simulated evolutionary models have not created artificial sentient life, a real question that remains is, “Are these strings of computer codes real beings?” They compete for resources, they self replicate, and they perish just like biological beings. However, answering this question will likely require a bit more thought and ethical debate.

If it is concluded that these computer strings are real organisms, then it is simultaneously conceded that human beings have created life, an act though by many only possible by their god (throughout many religions in the world). Proper synthesis of silicon life through a model based on evolutionary principles also goes a long way to prove the theory of evolution (for those who were not convinced by fossil evidence, DNA evidence, and a plethora of other biological data). While this is truly exciting, I’m almost afraid of the emergence of a sentient silicon organism because its species would evolve at a much faster pace than us, mere biological organisms.

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