Monday, January 23, 2012
Marconomic evolution 102 - identify some razors and make them disposable.
So in regards to the modern evolutionary synthesis, there are a few uses of parsimony which are so often fallen back on, a casual scientific observer would be forgiven for thinking they were *proven*. Not only are they not proven, but it is plausible that some may be impossible. However, because of the traditional religious contentions of impossibility being used to demonstrate something else, simple to understand but also impossible (supernatural intervention), I am distancing myself from conclusions that are also simple and rely on the impossible. No good science can come from believing in supernatural proximate causes. A few uses of Ockham's razor in evolution. 1) non-life to life transition happened on Earth. 2) The Weismann barrier (preventing direct feedback from the environment back to DNA) 3) Modern evolutionary synthesis (micro evolution leading to macro evolution and speciation due to random mutations and selection) 4) selfish gene (decisions based on the individual, rather than group selection) For instance in the book that I'm reading, number 1 is assumed to the point of it seeming proved, to a casual observer. Even the seeding of chiral amino acids etc. from asteroids/comets sees resistance from scientists as a hypothesis, despite evidence that all tested meteorites appear to have them. From what is now known about the Earth in the time before life, expectations given known conditions appear to be unlikely to even generate amino acids, let alone chiral ones, nor have a bounded niche where chemical evolution would be *expected* to occur. Most narratives involve a fair bit of "wishful thinking" chemistry, with the corollary that microbial organisms appeared, so it *must* be possible, no matter how mathematically implausible it seems. A naturalistic alternative would be that Earth was seeded with the *final product* ie single cell organisms, leaving the chemical evolution and non-life to life transition somewhere that both such an evolution and transition would be an *expectation*, and the transportation to Earth would also be an expectation. Although this appears more complicated, mathematical probability might say otherwise. 2) The Weismann barrier is said to prevent the environment from directly influencing inheritable traits. Thus selection based on shuffled Mendelian traits is the only feedback possible. Apart from there actually being evidence that the Weismann barrier is broken, the assumption is that they are exceptions, and thus the hypothesis holds as if it was proven despite evidence to the contrary. An alternative naturalistic explanation is that the barrier is merely a normal response to avoid copying errors when there is no adaptive stress to the organism. When there is adaptive stress, ie. drastic changes to environment, signals from the environment may be let through to mutate in appropriate ways. 3) mathematically, if the issue is reduced to the simplest organism, relying on random mutations, with natural selection, and cumulative mutations causing speciation, trillions of organisms, and thousands of generations would seem to be required for a single beneficial mutation to come out naturally. Translating to more complex organisms would appear to actually make it less likely. There are other naturalistic razors that would make beneficial mutations an expectation, but these are more complex and are burdened unfairly with having to be proven, while micro( not the extension to macro) evolution appears to be self evident and demonstrable to a point.