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03-08-2003, 04:58 PM | #11 |
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Hello JLK, and welcome- that's a pretty nifty little argument in two simple equations. I've never seen it before- can you direct me to any research which gives that estimate of 5 billion total species?
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03-08-2003, 05:28 PM | #12 |
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Thanx Jobar. There are various estimates for total number of metazoan species (I have edited my post since I left that qualifier out). 5x10^9 is the number by David Raup in his book Extinction, widely used even by creationists. I’ve seen other estimates ranging from half that to maybe ~8 times as much. Leslie Johnson (Princeton) thinks a conservative measure of estimated number of species is 2.5 billion. I believe the figure is mostly extrapolated based on known rates of fossilization and a small part perhaps on ecological considerations since species densities in various ecosystems have certain patterns. You could try looking up articles by Simberloff. For the number of metazoan species around today, one estimate is that 4x10^7 is the highside.
According to this quick and dirty calculation, we actually are finding transitional fossils far more often than we have any right to expect. The probable false premise is that the likelihood of finding each species is equiprobable. Fossil finds are more likely to yield a reticulate pattern of discovery. |
03-08-2003, 05:57 PM | #13 | |
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Re: Re: Re: a case for creation?
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My figure of 200 for transitional species comes from Tables 1 & 2 in Roger Cuffey's excellent paper, Paleontologic evidence and organic evolution, which can be found in Montagu's _Science and Creationism_ or the Journal of the American Scientific Affiliation 24(4). Cuffey's transitionals are clear intermediates found in the correct intermediate stratigraphic position. In other words, even creationists are forced to accept them as "microevolution." |
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03-08-2003, 07:03 PM | #14 |
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Thanks for the clarification and information, JLK. There is so much evidence supporting evolution, that I doubt anyone could be familiar with all of it. I learn new things every day, which is why I surf the forums.
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03-10-2003, 07:09 PM | #15 | |||||||||||||||||||
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a creationist replies
Gabe,
I am in agreement with some of the points of you colleagues but in disagreement on some others. I'll try to quickly address the points. My answers are rather rushed but I know you have a paper coming up so I hope this is helpful. I recommend you push us scientists hard. Make sure you count our assumptions. Is creation untestable, but evolution truly testable? For instance when someone says that strong evolutionary pressure will maintain a species relatively unchanged, question whether this is based on a testable mechanism or is based on an assumption (a little more fully developed below). Substitute the word God for evolutionary selection. That would argued to be untestable. But a hypothetical selection process at work millions of years ago is equally untestable. Don't let us be sloppy. I know I've been slow at developing some of the ideas over the last couple of weeks, but I didn't want to just give you some pat answers. Best wishes on your paper. Mike Quote:
M1: But there was clearly a very early explosion of life that was much faster than predicted. Quote:
M2:The stability is much more extensive than expected. Gabe, one point I would like to make here is also in relation to the untestablility of creationism (mentioned below). The above statement about "if selection is strong enough, a population can be genetically homogeneous or nearly so", is untestable. If I see stability, I argue for strong selection. If I see lack of stability I argue that is the evolutionary process at work. The statements rest on a hypothetical selection agent at work on that species millions of years ago that cannot be tested. What is the testable hypothesis here if no matter what is observed I argue it to be the evolutionary process? It may very well be that there was a selectable process going on, but that is a faith statement. Faith that the process was at work, even though I cannot demonstrate it or test it. Quote:
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I do mean above species levels to include classes of organisms. However, I am perplexed by the non-question begging comment. I don't understand what that means. Quote:
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M13: How is the 1% estimate made? Many of the same fossils are continually isolated arguing that large gaps in the record is not a major problem. What new intermediates are found all the time? Quote:
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While creation is hard to test, as mentioned above in M2, many of the arguments for the evolutionary process being at work are untestable as well. Quote:
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03-10-2003, 11:50 PM | #16 |
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This one is MINE! Hands off!
(But it will have to wait until tomorrow -- and when the advisor isn't looking.) theyeti P.S. What fool wrote this: "M19: As opposed to a classical enzymology type biochemist rather than a molecular biologist style biochemist." Does this guy have any clue what kind of "molecular biochemist" he is? |
03-11-2003, 03:27 AM | #17 | |
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Sorry, yeti, but I just want to address this one tiny point. You can have at the rest:
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Another strike against the notion of species design's being "best" is that the environment is clearly not a constant in time. We have copious evidence of this. We've endured ice ages. Forests have given way to grassland and vice versa. Concentrations of the various gasses in our atmosphere have changed over time and continents have drifted. Even if we postulate that any organisms originally created by God were "best" (whatever that means), clearly any shift in environment would have wholly negated that optimality. If you make a creature that is best at living in warm forests and then subject that creature to an ice age, that creature will no longer be optimally adapted for its current conditions. Any omniscent creator must have forseen that the environment would not be a constant in time and hence must have seen the futility in creating "optimal" creatures. I think this essentially destroys the argument that it is illogical for God to have created certain creatures that would have been viable but perhaps non-optimal for their initial environments. In response to the first portion of the post, common descent does not mean that things could be mixed and matched. In fact it means quite the opposite. Evolution in general leads to increasing complexity by adding beneficial changes onto existing genetic structures. Due to the vastness of phase-space for the problem at hand and the lack of a clear "best" solution to any given complex problem, it is highly unlikely that two separate evolutionary paths will result in the same genetic changes. For example, it is not likely that two species would independently evolve feathers. If the evolution was truly independent, their solutions would both be effective but almost certainly unique (it's hard to believe that only feathers as seen on today's birds will allow for flight). Hence if you see two species with very similar complex mechanisms for achieving a certain complex task, evolution maintains that they almost certainly had had a common ancestor that initially evolved the mechanism, or at least some primative form of the mechanism. |
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03-11-2003, 01:31 PM | #18 | |
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I was a little tipsy when I wrote that post late last night. It's not really my right to lay claim to certain posts as being my own to respond to. There's not enough action here as it is, so have at it. theyeti |
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03-11-2003, 03:59 PM | #19 |
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I'm wondering who this "Mike" is that Gabe talked to, whether Gabe had Mike's permission to post his message, and whether Gabe is capable of thinking for himself or whether he just wants to "be like Mike."
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03-11-2003, 06:26 PM | #20 |
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Dave...hehe...no, I'm not trying to be like Mike. I'm trying to understand this whole creation/evolution debate by observing how learned evolutionists would reply to Mike's views and claims. I must confess, I'm learning quite a bit. And yes, Mike knows I have posted his words.
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