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Digital Darwin
An anonymous reader writes "Using genetic algorithms to breed strings of computer code graphically, this week's Nature magazine describes results from Caltech and Michigan State. Their program is Avida. While they mainly mimic mutation, not genetic cross-over [or inheritance (thus wiping away much memory of initial conditions)], their simulations show how a short-term backward step in survival strategies can generate innovative advances. It is not unlike running a maze which necessarily involves testing alot of dead-ends, and thus shares the graphical look of Conway's classic Game of Life." Here's a National Geographic story about this as well, or see their press release.
> I think the minor problem of the small number of noisy anti-evolutionists would become even more minor. I mean, it's kind of hard to say that an algorithm doesn't work when you can compile a few thousand lines of c and then watch it work.
Yeah, as soon as I saw the article I thought, "How many evolution deniers will we dredge up this time?".
It would be nice if someone had an on-line hub linking to all the GAs that are free and source-available, so that people could download one and try it themselves, look at the code if they suspected the answer was cheated in, and maybe tweak some parameters to see that both mutation and selection are actually needed for such systems to work. (The evolution deniers on talk.origins are fond of attacking mutation and selection independently, as if one or the other should be sufficient according to the theory of evolution.)
Of course, some puppies would deny peeing on the floor even as you rubbed their nose in it, but we might as well inform those who are informable on matters of science.
Sheesh, evil *and* a jerk. -- Jade
I enter the fray reluctantly.
...") was that simulating something in a computer does not necessarily prove anything about the physical world. We can synthesize all sorts of things that have no analogy in nature. EA, AI, are fascinating fields inspired by evolutionary theory, but I fail to see how executing a computer program that assumes evolution in its infrastructure proves anything but that modelling evolution in software works.
The first thought I had when I saw the article (presented on Space.com as "Darwin Proved Right
For the record, I am not anti-evolution, though I may occassionally be noisy...
Trouble making decisions? Just flip for it.
Tierra was by Tom Ray, a pioneer in the AL field. It was a great idea, but failed to turn around with interesting biodiversity. You'd create creatures, they'd optimize themselves, some variants and parasites would evolve, but then things would simmer down within a few hours and you'd be in a steady state for ever.
;)
Network Tierra was Ray's response to this. It was supposed to allow a "Cambrian explosion" of biodiversity, by providing tons of (networked computer) space for the little creatures to explode into, and then specialize, in. This led to interesting migration behavior, and one of my all-time favorite web-pages, but it too failed to spark that je ne sais quois, that spark of life.
Anyways, it did spark Avida and the Digital Life Lab at Cal Tech. Avida is essentially a deeper look at the fundamentals behind AL. In Tierra, I think the design philosophy was something like "make it look a lot like a living ecological system and the life-force will appear out of the ether", and actually, Tierra was a great leap forward beyond more mundane genetic programming a la John Koza.
Avida, on the other hand, is much more systematic in exploring the parameter space (which is large and sensitive) for setting up an AL system. This turned out to be fruitful, as Adami found that only when certain, very narrow, environmental conditions were met would the little creatures start outsmarting that Creationist boogeyman, the Second Law of Thermodynamics.
Turns out that Tierra didn't have spatiality (needed to be more restrictive on who could sleep with who) and mutation rates (some power law math that's way over my head) set right.
But the real punch-line to this whole story is that the direct beneficiary of these insights in Microsoft! Hah!
Microsoft was funding Adami's work because Windoze crashed too much. They were searching for a way of programming - in this case using closed instruction sets like Avida's (another deep topic) - that would be inherently robust to problems like seg faults and illegal instructions.... e.g. Adami's instruction set was engineered so that little programs (creatures) couldn't crash the Avida VM when they mutated into new, unknown programs.. or in Windoze's case, when a coder did something stoopid. It's funny that MS was researching this, since releatively low-tech solutions such as protected memory and QA take care of this. (not to mention Java