DNA and evolution

by onacruse 33 Replies latest watchtower beliefs

  • onacruse

    rem, I just did a little reading on replicators and natural selection.

    For the purpose of discussion, let's grant that, however improbable, there was indeed at least one self-replicator produced by an accident of purely physical processes. Scientific method requires that this step be reproducible if it is to be accepted as anything more than a speculation. So I found it interesting to read in Britannica (bold added):

    It is possible for RNA to replicate itself by mechanisms related to those used by DNA, even though it has a single-stranded instead of a double-stranded structure. In early cells RNA is thought to have replicated itself in this way. However, all of the RNA in present-day cells is synthesized by special enzymes that construct a single-stranded RNA chain by using one strand of the DNA helix as a template.

    This, together with your comment that "There are several different hypotheses about what these replicators could have looked like" suggests to me that this (apparently) essential step to the development of DNA is only conjectural. In that case, wouldn't I be compelled to go by what I can see, in terms of straight-forward demonstrable physics?

    Also, as far as natural selection is concerned, it's important to distinguish between a descriptive principle and an explanatory theory. Identity and Reality (Emile Myerson, pp. 311-6) uses the example of Carnot's cycle:

    Indeed, Carnot's principle is an empirical law, directly observable; it is the most general and most common of rules--it governs the totality of phenomena. This is far from being so for the variability of animals and vegetables; even admitting that this is an absolutely demonstrated fact, it is far from impressing itself upon our attention as much as the fact of the establishment of equilibrium of temperature. That is why it could not really become a part of science until an explanation of it had been found, or at least until a way had been indicated by which it seems possible to find an explanation. This was done, or at least attempted, by the initiators of the concept of evolution in biology--Lamarck, Darwin, Wallace. Did they succeed? Opinions differ on this subject, even amongst biologists.

    Carnot's cycle is explained by Maxwell's theory, which provides the underlying (and apparently universal) physical principles that "drive" that cycle. In contrast, "natural selection" remains, in that respect, unexplained. (Myerson proceeds to illustrate how the lines between these two aspects of science often becomes blurred, as we can tend to 'read' teleological meaning into what we empirically observe in the world around us).

    Which brings us back to the beginning:

    Moreover, in supposing this reduction to mechanism carried to its very limit, it is evident that the primitive being, the source of all others, must in its turn be conceived as having evolved from inorganic matter. This conclusion may seem hazardous from the experimental point of view, since the results of micro-biological research tend to make us reject spontaneous generation; it constitutes, however, the necessary completion and crowning of the edifice, as eminent evolutionists have proclaimed it.

    So, on the one hand I have no rational choice but to accept the clear empirical evidence of the cross-species similarity of DNA as evidence for the process of evolution. But on the other hand it doesn't provide me with an explanation for evolution, based exclusively on physical mechanisms.

    Of course, my belief in a supernatural being directing these events doesn't explain anything either.


  • rem
    So, on the one hand I have no rational choice but to accept the clear empirical evidence of the cross-species similarity of DNA as evidence for the process of evolution. But on the other hand it doesn't provide me with an explanation for evolution, based exclusively on physical mechanisms.

    Sure it does. You're just confusing Evolution with Abiogenesis. Notice I specifically used the word "hypothesis" when speaking about the original replicators (Abiogenesis). We don't know how they got there. We have guesses, but we don't know for sure. God could have done it, but that's just a 'god of the gaps' explanation. From what we know today, though a god or gods may have started the first spark of life, there is no reason to seriously believe said god(s) were tweaking with life after it started to evolve.

    I personally don't put much stock in 'god of the gaps' theories because, historically speaking, they have always proven to be incorrect.


  • onacruse

    rem, you have indeed been careful to stipulate that there are certain aspects of evolution that remain hypothetical, and I appreciate that. Until 10 years ago, the most irritating thing (on this issue) I heard people say was: evolution is an established fact; since then, to hear: evolution is obviously wrong. As so often happens in life, the "truth" is frequently found between extremes.

    As far as abiogenesis and evolution, it seems to me that they are essentially bound up together, at least insofar as consistent scientific explanation is concerned: the generative principle must be intrinsically related to the generated consequences. For example, Weinberg and Hawkings have devoted considerable effort to correlate the nature of our space-time geometry with a quantum-mechanical "starting point" that shows a generation and continuum of physical principles from the very beginning of the universe. And Einstein spent the majority of his life searching for a GUT. And for evolution, as Myerson said above (bold added):

    ...spontaneous generation...constitutes...the necessary completion and crowning of the edifice, as eminent evolutionists have proclaimed it.

    Well, if this may be the Achille's heel of evolution, then equally so is what Carl Sagan said about God in Broca's Brain (p. 130):

    There can, of course, be no disproof of the existence of God--particularly a sufficiently subtle God. But it is a kindness neither to science nor religion to leave unchallenged inadequate arguments for the existence of God. Moreover, debates on such questions are good fun, and at the very least, hone the mind for useful work.

    If God did indeed direct the development of DNA from a single biogenetic molecule, and progressively up through to the incredibly complex DNA patterns we see today...well, He was awfully subtle about it.


  • Panda


    The creationists "tinkering" was no such thing.

    The catalyst after the Big Bang was gravity.(The perturbation which initiated the big bang would also have had to do with electron orbits which could also cause gravity, simply by perturbing the orbits of other electrons.) This is why supercolliders are so important to research, but alas not enough profit in them.

    The elements no longer existed in their unperturbed state. The explosion itself would throw enough elements together to begin to form molesules and rocks and ice. Remember those electron orbits of the elements? Well certain elements will bind together because of those orbits. Each orbit either accepts or rejects electrons from another element. Ex.H 2 O not actually bond two hydrogen and one oxygen molecules. For one existing water molecule you must write 2H 2 O for the electron orbits to share electrons and actually become water. The point is that the orbiting electrons cause a gravity shift even at such micro levels.

    The huge spheres we call stars are mainly hydrogen which continually burns off any atmosphere that ever had to form there. The gravity of these active giants pulls on the masses of rocks and their moons. Then because of the mass of individual planets the gravitational pull on the sun actually makes it waiver in it's orbit.

    The reason earth is so speacial is that it has 2 large (huge) outer planets which take most of the space debris hits...allowing TIME for the earth to benefit from the sun causing chemical reactions on earth... LIFE got the time needed to form proteins to form DNA which is pretty much the same in everything living on earth.

    Thanks for such an interesting thread, Panda

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