August 04, 2008

Becoming plants

As any computer scientist can tell you, evolution is awesome. Properly implemented as an algorithm, it can design aircraft, ships, trusses, antennas, just about anything that can be described with a "chromosome". So long as you have some notion of what a "good" design is, and a way to test for it, the genetic algorithm can usually make substantial progress in finding one, through many generations of reproduction, crossover, and mutation.

As an aside, genetic programming is an idealized version of the way we think biological evolution works. It's probably pretty close, and it can provide valuable insight into the evolution of species, but it's not the same thing. On more than one occasion, I've seen people point to GP as "proof" of biological evolution. It isn't, any more than a flight simulator is proof that airplanes can fly, and claiming it as such is a disservice to the work of archaeologists and evolutionary biologists.

Anyhow, in computer science terms, GP is a method of search. Though better than many methods at escaping local minima, it isn't perfect.  In a program, this could mean a set of populations that never produces a very good design, even after many generations.  There are parallels in biology.  Consider that the efficiency of plant photosynthesis tops out at just over 6%, and most plants are lower than that.  That amount of utilization is enough to power all the plant life on the planet, and it hasn't changed much in a long time.  Current solar panels already have that beat (10% to 20%). A plant species that could utilize solar energy at those rates would have a strong advantage over other plants in it's niche, and possibly beyond it. Whether the lower efficiency of plants it a fundamental limitation of DNA-based biology or simply "good enough" isn't the point; plants aren't as good at as we're becoming.

Humanity, near as we can tell, has a unique approach to competition among species. Intelligence, situational memory, and planning are only part of that approach, the merely physical and biological strengths that propelled us to early success. Symbolic communication -- facilitated by our intelligence -- led us to culture, to memories that survive individuals, and thus to complex technologies. With them, we became more than just hairless apes with cool hands and bad backs. We became, quite simply, better at evolving than any other complex animal.

Technology lets mankind be nearly mythological in power. We can communicate with each other across the globe. We have durable "bodies" that we can inhabit as needed that are stronger and faster than any animal that's ever lived, and allow us to explore any environment, even places where no other life may tread, largely with impunity. We've even created machines to do the boring parts of the very cognition that's made us so successful, so that we can do even more of it. As our powers have grown, so have our appetites. All the miracles we employ require energy, far more than our tiny bodies could possibly metabolize. So we built engines and motors, artificial metabolic organs capable of ingesting otherwise indigestible "foods" with incredible energy density, first coal and petroleum, later uranium and thorium.

All the "foods" we've found to feed our miracles, however, have limits and costs. They aren't depleted, by any means, but they aren't forever, and we can foresee a time when they may become so scarce as to be effectively gone. One possible, long term way out of this (barring some lucky breakthrough in fusion) is to become plants.

I don't mean that we should turn ourselves green (physically or metaphorically). We became what we are by being better than any other animal at literally everything they do, using technology to do so. To continue on our path, we have to find ways to be better than any plant at everything they do. Solar cells will be our leaves, spread out to catch the radiance of Sol. Batteries or other storage will be our sugars and fats.  Will it be enough power?  For a while, surely, and it will get us further along the way to whatever comes next.

I'd much, much prefer fusion, by the way.  We should still beat plants at their own game along the way, but fusion is nearly a necessity if we ever want to leave the solar system.

Posted by: leoncaruthers at 10:12 PM | No Comments | Add Comment
Post contains 729 words, total size 5 kb.

Comments are disabled. Post is locked.
21kb generated in CPU 0.0088, elapsed 0.1495 seconds.
56 queries taking 0.1442 seconds, 192 records returned.
Powered by Minx 1.1.6c-pink.