FOR generations, the Avidians have been cloning themselves quietly in a box. They're not perfect, but most of their mutations go unnoticed. Then something remarkable happens. One steps forward, and that changes everything. Tens of thousands of generations down the line, some of its descendents will evolve memory.
Avidians are not microbes, or sci-fi alien life forms. They are the digital offspring of Charles Ofria and colleagues at Michigan State University (MSU) in East Lansing. They "live" in a computer world called Avida, and replicateMovie Camera using strings of coded computer instructions instead of DNA. But in many ways they are similar to real life: they compete with each other for resources, replicate, mutate, and evolve. They - or things like them - might eventually evolve to become artificially intelligent life forms.
Similar to microbes, Avidians take up very little space, have short generation times, and can evolve new traits to out-compete their rivals. Unlike microbes, their evolution can be stopped at any time, reversed, repeated, and the precise sequence of mutations that led to the new trait can be dissected. "They're wonderful evolutionary pets," says Ben Kerr, a biologist at the University of Washington in Seattle.
They could become so much more. At the 12th annual international conference on artificial life in Odense, Denmark, this month, philosopher and computer scientist Robert Pennock of MSU will present the findings of experiments in which Avidians were made to evolve memory. ...
"In the past, the approach has been to start with high-level intelligence and reproduce that in a computer," says Grabowski. "This is the opposite. We're showing how complex traits like memory can be built from the bottom up, from things that are really very simple." To demonstrate this, Grabowski has evolved Avidians that move towards a light source. Her colleagues then translated the evolved "genome" into code that could control a Roomba robot. It worked: the Roomba was attracted to glowing light bulbs. ...
"Brains that have been evolved with HyperNEAT have millions of connections, yet still perform a task well, and that number could be pushed higher yet," he says. "This is a sea change for the field. Being able to evolve functional brains at this scale allows us to begin pushing the capabilities of artificial neural networks up, and opens up a path to evolving artificial brains that rival their natural counterparts."
via Artificial life forms evolve basic intelligence - life - 04 August 2010 - New Scientist.
Some day the Avidians may evolve so far that they will be doing experiments on us.
We have learned many interesting things about evolution from computer models.
Nature Reviews Genetics 7, 109-118 (February 2006):
... Digital genetics experiments reveal that genes that evolve with high mutation rates are subject to a new selective force: the pressure to develop robustness with respect to mutations. At sufficiently high mutation rates, robust replicators out-compete faster replicators. ...
Genes are not just passive repositories for information; they are active participants in the preservation of this information. Environmental regimes exert different pressures on how the information in a gene should be organized, leading to different levels of gene overlap and linkage
... Sexual recombination also changes the way in which information is stored in genes, leading to a more modular 'coding style' than is found in asexually reproducing clones. Because modularity affects the degree and form of the interaction of mutations (epistasis), such an adaptation can lead to synergistic epistasis — a prerequisite for sex according to Kondrashov's theory.
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