Biology is faced with the problem: the field in general does not understand much of what it studies. One method of solving this is to study the smallest organisms known, in an effort to “understand 100% of something small.” This is a typical engineering approach, to understand the smallest system first, then work up to attempting to understand larger systems. After understanding the organisms, of course, we have a better chance at modifying them (their DNA) into something useful (or, rather, something that actually lives at all).