Having started this blog, and speaking of memes and The Selfish Gene, has made me think about the second chapter of that book called The Replicators. This has aways been a topic of some interest for me as it largely unknown. After that first self replicating molecule is assumed natural selection can take off and we can basically map it out from there. However, that is a BIG assumption to make. To have a theory, in this case Evolution by Natural Selection, based on the existence of something, in this case a self replicating molecule, who's existence you cant explain is a little troubling.

Dawkins tackles this problem in a somewhat satisfying way in the aforementioned chapter. He lays out a plausible scenario for how a self replicating molecule could arise. As any reader will quickly realize, and Dawkins is the first to point it out, the scenario is a pure speculation. However, it is what I refer to as a "good" speculation. What is a good speculation? It is a possible scenario that, like all speculation, is not formally grounded in observation or evidence but follows certain rules that some other types of speculation do not. For example, a good speculation should of course follow the rigors of logic and reason. It should also make as few assumptions as possible. It should fit with other observed phenomenon and know laws of nature and physics, building upon what is known. When all of these criteria are met it can, in my opinion, be called a "good" speculation.

If one has made a good speculation there should be no reason that events could not have unfolded as described. This is exactly what Dawkins does regarding the origins of the self replicating molecule. He takes what is known from chemistry, physics, and biology and constructs a plausible scenario. Note that I say plausible and not possible. This is a very important distinction. Many things are possible that are not probable. Due to the fact it is a speculation we should not hope for probable. We need to find something in between possible and probable. I believe we should be looking for a plausible speculation.

Using what we expect the early earth might have been like Dawkins creates a model that introduces amino acids into the environment. Using what we know about how protein molecules coil up into a stable state he constructs a model for how amino acids might have linked into simple proteins. Using what we know about RNA, its similarities to both protein and DNA, he constructs into his model the arrival of the replicators.

What is of importance here, and what I hope you will take away from this post, is the value of making these kinds of good speculations. Aside from the obvious reasons of advancing thought and making new models to be empirically tested to find truth there is another important role. That is to usurp "bad" speculation. Once we have a plausible and natural account of how something might have happened we can automatically throw out the implausible models. It is of supreme indifference if the good speculation is true or not. It doesn't make a bit of difference if self-replicating molecules did arise as Dawkins suggests. What matters is that they COULD have arisen as Dawkins suggests. Once you have a good speculation that follows all the "rules" I outlined above you have to discard any previous speculations that did not follow the rules. You only fall back on bad, wild or improbable speculation when there is no way to account for something in a plausible way. It is true that when you have eliminated all possibilities whatever is left, no matter how improbable must be the truth. However, you can only go to the improbable once the probable and plausible causes are either ruled out or nonexistent.

This is something that seems like common sense to me but many people miss it entirely. They are all to willing to jump right to the end of the road, the improbable, without ever casting a glance at the good speculations they passed along the way. They seem to be possessed of the notion that because they are all speculation they are all equal and can be chosen from at will. As I hope you will see this is a fundamentally flawed way to go about it. While speculation should be lower down the intellectual ladder than fact or strongly supported theory it is essential that it is placed higher on the ladder than bad speculation.