Tianran Chen wrote (in private reply to my earlier post, but I thought this discussion generally interesting, hope that's ok Tianran): But just because it is the genes are being manipulated DIRECTLY does not mean thati do agree that many very valuable point of view had been criticised unfairly due to their 'group selection' nature. however, i am quite convinced that there are fundamental problems embedded in it.first of all, i think to look at evolution through a individual or group point of view is always dangerous. since they are not the fundamental unit of evolution. evolution, (in the sense which it is referred to in most biology context) DOES NOT manipulate individual NOR species directly, instead, it is always the small packets of genetic information (such as gene or meme) that is being manipulated. so, it is a safe theory about evolution should always able to be translated into languages in terms of gene or meme, and if a theory cannot, then it is not safe to use. and this is exactly the problem of 'group selection'. other factors are not important to understanding what's going on, and understanding what factors may be most ESSENTIALLY driving a particular evolutionary direction. For example, biology now understands that it is not single genes, but sets of genes acting together in regulatory networks, that are the fundamental units of "functionality" and therefore, of "adaptive or maladaptive functionality" in organisms. You'll note that I was the one who started the practice of putting "GOAL" in quotes, indicatingBECAUSE THE EVOLVABLE "GOAL" IS NOT SIMPLY TO MAXIMIZE THE CHANCE OF SURVIVAL OF AN ORGANISM OF THE NEXT SHORT-TERM ENCOUNTER. THE "GOAL" IS TO MAXIMIZE THE PROBABILITY OF SURVIVAL OF THE SUM TOTAL OF ALL OF THE ORGANISM'S ENCOUNTERS UP TO WHEN THE ORGANISM REPRODUCES.disagree. a gene's 'goal' is to maximize the availability of its own copies in the entire gene pool. so to look at it in individual level, it implies that an individual is more likely to behave in such a way that it tend to maximize the chance of some gene to replicate. and 'some gene' here, refered to not only genes in its own body, but also in other's body. one thing to notice here is that very often, individual try to do so at the cost of its own chance for breed. such behavior can be found commonly in social animals, symbiosis systems, and etc. again, here mention about the 'goal' of a gene. but what i really mean is that due the the selection pressure, genes who had survived selections behave in the way as if they had the 'goal' although they are really blind about future. so the 'goal' is simply a short hand notation, do not take it literally. that it is not to be taken literally, but as a stand-in or short-hand for a complex set of factors that lead to a tendency of evolution to support one kind of trait over another. valid theories has to be general enough to explain all sorts of things in the domain, not just part of them. and now better theories does exist (such as self-gene, and memic evolution). so 'group selection' SHOULD be marked as obselete. I disagree with your last clause. To me, a fan of general theories of emergent complex ordered systems, of which life evolution is only one example, one of the most fundamental questions is what is the best scope-boundary that best defines what is the most "interesting" or "systematic" or "robust" system. What I mean by this is that we have a degree of free reign about what elements (of the world, universe, what have you) that we choose to include in our definition of a system. Or in other words, for ANY particular set of elements that have something to do with each other, some crazy guy will have the right to call THAT collection a perfectly valid system; his most important system perhaps. So you can imagine possible "system-scopes" or "system-boundaries" as being an infinitely variable set of concentric spheroids overlapping, Venn-diagram-like, being at wide ranges of spatiotemporal scales, and including/excluding different elements. Faced with such a scenario, one is forced to ask "are there any universal principles that would let me decide which "boundary-spheroid" is the most "systematic" or consideration-worthy system (at this spatiotemporal scale in this vicinity, anyway)? Or, both generalizing and specializing a bit; given that, for example natural systems tend to be "fractally functional"; that is, comprised of nested layers of smaller-scale functional systems, we can ask "how (at what scale boundaries) do we best divide this natural system up into nested layers (i.e. where if anywhere are the best-defined layer boundaries (those layer boundaries that are the best at separating of distinct functionalities) , and for EACH spatio-temporal-scale layer of this natural system, what are the best-defined system-scope spheroids? What are the system-scope spheroids that perhaps are the best clusters of negative entropy at that spatiotemporal scale? Now to me, the evolutionary issue is to figure out how and why "fractally functional" natural systems evolve their functionality at all of their spatio-temporal scale layers (and thus how they maximize, AT EACH LAYER-SCALE (and fractal-functionality system level) their pattern robustness and pattern-longevity, compared to competitor patterns. The direct variations (mutations, recombinations) in genes are an important part of this picture, to be sure, but analyzing the whole evolution-trend question in terms of individual mutations of individual genes is akin to saying that "it's all the quantum wave equation, really" about all of the phenomena in physics, large and small. It's true, but it's also fairly trivially true. Every theory has a scope of application, and there is room for other theories at different levels to explain aggregate phenomena that are not directly or concisely explainable by the purely reductionist "atomic" theory. Many of the "aggregate-level" theories will be wrong, and/or hard to demonstrate, but that does not say that all of them are wrong. Just that the right ones will be hard to tease out. Cheers, Eric |
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