Saturday, October 31, 2015

Interstellar Baggage – Part 6 – Genetic Options

We on Earth are in the midst of a climb up the learning curve of robotics. Each decade brings some new advances. Progress is slow as creating a new quasi-living thing, even if out of standard parts, is a complex process. Many standard parts are not acceptable in some attribute, so the materials science needs to be done to make them more flexible or rigid, strong or lightweight, reliable or intensive, or many other aspects. Each major step gets much notice, as do the intermediate steps. Thus, we here think robotics is a big thing.

It is a big thing, but maybe not the biggest thing. Earth technology in the biological synthesis area is nowhere as far along as it is in robotics, and while genetic discoveries get press, they don’t capture the imagination of the public like robots that drive cars or deliver medicine or clean floors or keep airplanes flying or many other tasks. This means that when we assess how an alien planet, which is already past asymptotic technology, meaning they know everything important, would divvy up their tasks between robotics and genetics, we think of robotics first. It’s time to think of genetics first.

For a landing ship, some choices have to be made about what to put in the payload. Each kilogram carried at some fraction of light speed over a distance measured in light years caused a huge amount of money, or energy if that is what the home alien world uses for currency measures. How do you get those kilograms down and still make the colony successful, and able to establish self-sufficiency in a short time, using only what they brought on board?

They have some essential needs that must be met, and these have to be sourced from the planet itself once the supplies on the lander give out. The way discussed in a previous post was to turn into hunter-gatherers until some basic infrastructure was created. If the planet is as we assumed, a best case world, this would work assuming the daily average amount collected by those individuals engaged in this occupation was sufficient to feed the whole landing party. Also discussed was the need to have something which could both replicate itself and provide something necessary to the landing party. The first thing that likely comes to mind is a manufacturing robot that can create another of itself and mining and mineral processing equipment as well. This satisfies the construction problem.

Why not just have something easy to grow, using only locally available materials plus photons from the local sun? Plants are fine, and can be made to grow fast. They can extract trace minerals from soil, and absorb carbon dioxide from the air, and together with solar photons, produce practically anything. Having specialized plants for the landing party means they only have to carry some seeds, almost nothing in weight. Maybe a watering can needs to be brought along. This way nutrition is taken care of, and some fast-growing tree-like plants can provide structural materials.

What about power? Does this mean having a robot that mines various minerals, extracts the elements needed to build solar panels, and then builds them? Or does it mean having a seed for a plant which excretes burnable fuel?
What are the limits to what organisms can be coded to do? If a probe succeeded in finding minerals accessible on the surface, can an organism be designed and built that is smart enough to go to that location, perhaps matching an image shown to it of the surroundings, and then release some microbe which chemically extracts the needed minerals? Can a second organism, similar to the first, be instructed to go to the same location and harvest the microbes, and bring them back to the landing site, where it would feed them to another synthetic organism, which extracts the desired element and deposits it on an external surface, like the underside of its leaves? We on Earth are so far from understanding the powers and limitations of genetics that we have no good way to grasp what is reasonable to assume and what is not.

We do understand some simple biological processes that do one step of this process, under certain conditions, and that is the extraction, or leaching, of certain elements out of wet rock. Copper, iron and uranium are examples where it is sometimes practical to bioleach. These were discovered organisms. If alien civilization is past the genetic grand transition, where they can synthesize organism able to perform chosen tasks, the gamut of bioleaching might be much wider, both in elements extracted and conditions under which it can be performed. There are obvious requirements, meaning that there has to be energy available to the organisms involved. We on Earth are familiar with symbiotic arrangements, occurring naturally, between fungi and algae, which when biologically integrated are called lichens. The fungi provides the ability to hold onto a rock, and to provide nutrients to the algae, and the algae are photosynthetic, providing an energy source. Perhaps an alien civilization would use this simply pairing as a template for their own synthetic mixtures of microscopic organisms able to extract a variety of minerals in dry or wet situations.

As far as the higher order synthetic organisms, able to navigate on a new planet, there are several options. Birds on Earth can navigate large distances, but typically it is learned via generations. Sensors can include polarization or magnetic direction, as well as image matching. Even something as simple as an insect can navigate seasonally. An alien civilization could come up with a symbiotic pairing, with one organism doing the navigating and the other providing sustenance along the way. As much intelligence could be added into either as was needed to be highly reliable and effective.

Another need the landing party has is gestation. It would be possible to bring an industrial gestation machine down, but why not grow one? From a synthesized single cell an organism capable of gestating the larger organisms needed could be grown, and once that starting hurdle was passed, it could be used for gestating anything desired, including the next generation of aliens. Pack animals could be gestated to handle short distance traveling, or something that could be ridden for hunting or other purposes could be as well.

The tradeoff between robotics and genetics is obviously highly situation-dependent, and highly task-dependent. Whether genetics could provide a major weight reduction for a colonization ship payload is not clear from the little we know, but we do know that we cannot rule it out, and that there may be many advantages.

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