... might be reconciled with entropic processes.
The earth is not a closed system. It receives more than enough energy from the sun to drive evolution and an increase in biologic complexity.
DNA and evolution
by onacruse 33 Replies latest watchtower beliefs
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drwtsn32
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Satanus
Rem
Ok, i can see that working in microevolution, which is likely what the process was that you referred to as having been observed 150 yrs ago. In the evolution of one kind (is genus the scientific term?) into a another/higher one, i just wonder if that process is enough. As far as i know, it has never been observed, although some say it is going on even as we speak. Yet, from my understanding of fossils/archeology, scientists now pretty well agree that it goes in fits and starts. Does that mean that it turns on and then turns off? If it turns off, then how can we be sure it is going on now?
SS
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drwtsn32
... it has never been observed ...
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rem
Craig,
So I'm particularly interested in how the "selective pressure" process you refer to might be reconciled with entropic processes.
Drwtsn correctly stated that there is ample energy coming into the earth from the sun to reduce entropy. Just because the average entropy of the universe overall is increasing does not mean that there cannot be pockets of decreased entropy. If this were not so, then almost everything would be impossible, including weather, fetal development, drawing straight lines, etc.
SS,
In the evolution of one kind (is genus the scientific term?) into a another/higher one, i just wonder if that process is enough.
It is enough and the reason is deceptively simple. Just because the different genus appear to be so different today doesn't mean that the proto-genus organisms that branched off into the several kingdoms were that different. On the contrary, they were just as alike as related species are alike today. The only difference is that they have have millions of years of divergence behind them now. The only reason they are so spectacularly different is because they were among the first to diverge and today the differences seem very great. Remember, you are seeing their progeny, not the actual proto-ancestors.
As far as i know, it has never been observed, although some say it is going on even as we speak.
No one has observed the continents move in a giant leap from the single large continent they started out as to the several we have today. We do observe, though, the tiny movements the landmasses make accross the globe. Tiny individual changes are enough to make huge change, given enough time. It is a fairly logical conclusion that the continents are where they are today because of these tiny or 'micro-movements'.
Genes are similar. Tiny individual changes in the genetic code are enough to make huge 'macro' changes over millions of years. Just as the continents are currently moving (and we can measure the movement) the DNA in all living creature populations are changing, and we can measure that change as well. There is no known mechanism that would keep genes from changing outside an arbitrary 'genus' line. If there were such a mechanism, micro to macro evolution could be doubted. There really is no reason to doubt that life we see today is the product of trillions of minute changes over time shaped by various forces such as natural selection, sexual selection, genetic drift, and others.
Yet, from my understanding of fossils/archeology, scientists now pretty well agree that it goes in fits and starts
It does, but the fits and starts are only fast in geological timescales... we're still talking about tens and hundreds of thousands - even millions of years. Evolution is still an extremely slow process from a human's point of view.
Does that mean that it turns on and then turns off? If it turns off, then how can we be sure it is going on now?
Punctuated equilibrium is a theory that attempts to explain this. The theory is that most populations reach a point of stasis. That is, the populations gene pool pretty much stablizes and there is not much evolutionary pressure. Then when there is some type of climactic change or the organism populations migrate to an area where they become split apart, say geographically, they may evolve more quickly since there are new selective pressures. This isolated population may evolve quite rapidly (tens to hundreds of thousands of years) while away from the parent population. This one way how a population can split into two species.
This can happen so fast that the fossil record will just show a new species pop out of nowhere because it is not granular enough to catch the change. Also, the species may actually diverge at a different geographic location and then rejoin fully evolved and appear to come from nowhere geologically speaking.
This discussion can get quite technical, but there are known reasons for the phenomenon you are describing.
rem
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onacruse
Hmmmm...very interesting.
As far as punctuated equilibrium is concerned, it makes perfect sense. Malthusian population models are convenient, but don't include the "critical point" considerations of unique events.
I've never explored the ramifications of isolated "pockets" of non-entropic development. Your points are well taken. Wouldn't this still imply a terminal point? If so, wouldn't this also imply a genitive point, and a generative force?
Craig
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Satanus
Thanks guys. Drwtsn, I managed to make it through one of those refs. There is some food for thought. This was interesting:
5.1.1.4 Raphanobrassica
The Russian cytologist Karpchenko (1927, 1928) crossed the radish, Raphanus sativus, with the cabbage, Brassica oleracea. Despite the fact that the plants were in different genera, he got a sterile hybrid. Some unreduced gametes were formed in the hybrids. This allowed for the production of seed. Plants grown from the seeds were interfertile with each other. They were not interfertile with either parental species. Unfortunately the new plant (genus Raphanobrassica) had the foliage of a radish and the root of a cabbage.
Also, just what exactly constituted a new species took a long time being settled, if it has been, even now. That's why i still use the term 'kind' sometimes. I was surprised they didn't use the examples of the horse and donkey species.
SS
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Pistoff
Of course this is a gross oversimplification of what natural selection really does
Please spare us the crappy analogies; seems too much like the KH.
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rem
Arrrghh.... lost my post. Here goes again:
Craig,
Wouldn't this still imply a terminal point?
Yep, entropy always wins in the end - even over pockets of reduced entropy, like our solar system. 2nd law of thermodynamics at work.
If so, wouldn't this also imply a genitive point, and a generative force?
The ultimate genitive point would be the Big Bang. During the Big Bang the universe did not expand uniformly, creating pockets of reduced entropy, such as our solar system. The ultimate generative force could have been the universe itself (uncaused), a meta-universe, one or more gods, etc. Nobody really knows.
rem
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rem
Pistoff,
Please spare us the crappy analogies; seems too much like the KH.
What was crappy about the analogy? The fact that it showed how a filtering process such as natural selection is not random?
rem
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onacruse
rem:
The ultimate generative force could have been the universe itself (uncaused), a meta-universe, one or more gods, etc. Nobody really knows.
Again, very interesting. Hawkings has provided some compelling theoretical models that include a quantum-mechanical "self-generating" universe.
It's that "nobody really knows" phrase that's the big question, eh? To continue to the last paragraph of the article I quoted above:
The early evidence already suggests that perhaps several thousand human genes have undergone intense natural selection since our ancestors split with the chimp lineage. And those genes can only build a modern human being by cooperating with one another rather than working alone. This comes as no surprise to scientists who have studied the evolution of other animals. "We look for simple answers, but we almost always find a mess," says Carroll [Sean Carroll, geneticist at the University of Wisconsin]."
Craig