dimitrov@csd2.UUCP (Isaac Dimitrovsky) (06/03/85)
[] Thanks to Dan for continuing the discussion on isolated species. I still don't understand why no other creationists are willing to touch this topic. Anyway, Dan responded to two questions in my note. I'll get the less important one out of the way first: >> Also, why should >> the amount of time isolated have any correlation with the number of >> unique species? Or, if you are a recent creationist, as Dan is, why >> should the amount of time isolated, estimated using evidence you >> dispute but which is independent of biology, have any correlation >> with the number of unique species? > > This is a dead-end question! The amount of time that has transpired > after the flood is not enough time to account for the development > of unique species. Unless one assumes an old age for the earth, there > is no correlation to speak of. I guess I didn't phrase this question clearly enough, since it was a side point to the main question below. What I meant was, the amount of time a habitat has been isolated is estimated using methods such as plate tectonics. While you may dispute these methods, they have nothing at all to do with counting isolated species (this is what I meant when I said they are "independent of biology"). So if you don't believe that these species evolved then there is no reason I can see, barring a conspiracy between biologists and geologists, for there to be any correlation between the number of unique species in an isolated habitat as counted by the biologists and the time the habitat has been isolated as estimated by the geologists. I was therefore asking for a creationist explanation for this correlation. Now, to the more important question raised: >> What are the odds of all those isolated species migrating >> from the ark (or, if you are a creationist who doesn't believe the ark >> existed, from wherever they were created) to "their" islands without >> leaving any trace on the mainland, and without some members of the >> species also winding up on other, faraway islands. > > As far as the odds argument, let me first state that I never use the > odds argument against the formation of life. As a certain evolutionist > pointed out, odds are relative. The example was that if you tossed > 10 million dice simultaneously, the result would be one of amazing odds. > If calculated beforehand it would be considered impossible. The odds > of animals migrating and leaving behind no offspring in particular places, > becomes irrelevant if in fact they did so! I believe that you are misinterpreting the odds argument here, but the error is a bit subtle so it may take me a while to express it. Here goes: Suppose we have a theory A about something which requires that a very unlikely event occured in the past. To me at least, this would be a very disturbing aspect of theory A. In fact, if there is another theory B competing with A which does not require this unlikely event to have occured, this to me would be a strong reason for favoring theory B. To take a couple of non-inflammatory examples, suppose I come across a hundred dice, all lying with their five face up. I would be inclined to think that they had been placed that way, rather than that they had been randomly thrown and wound up that way. Again, suppose I enter a bank and see someone open a safe with a twenty number combination. I would be inclined to think that the person knew the combination beforehand, rather than randomly guessing twenty numbers. To take an inflammatory example, if the origin of life from nonlife required a very unlikely event (say, one with a probability of 10^-600), this would be very disturbing to me, and I would then be more inclined to something like theistic evolution (i.e. God got things started by creating the first life forms). (Note that this is independent of the question of whether evolution has occured). I should note that there *is* apparently a school of thought on the origin of life that says that it was a single, very unlikely event. To me, though, this is very unsatisfying and if this was the only current opinion on the subject I would be inclined not to accept it, as I said above. The refutations of this argument against the origin of life (and in fact against all odds arguments like the above) which *are* satisfying to me are of the type: 1. There are some not immediately apparent mechanisms which make the event not so unlikely after all. For example, we could discover that the dice in the first example are weighted so that they will almost always fall with five up. In this case, we might decide that the dice might have been thrown after all. As another example, we could find that because of chemical laws some types of reactions are more likely than others. This might make us revise our estimate of the probability of the origin of life from nonlife. *or* 2. While the event that occured *may be* very unlikely, lots of other events could also have occured which would have been equally "good". So the theory actually calls for only one of a class of events to occur, and the probability of this is much higher than that of each particular event. For example, we could discover that the safe in the first example will actually open with any combination not containing a three. In this case, we might decide that the person opening it might not have known the combination after all. As another example, we could find that there are many different possibilities for a simple life form. This might make us decide that the probability of *some* simple form of life arising is higher than previously thought. Let's apply this to the isolated species topic (Finally!). You say that the odds of the migrations which occured are irrelevant, since they did occur. But we have two alternative theories about why the unique species are distributed the way they are, so the fact that your theory requires such unlikely events is a strike against it. To refute this objection using the methods above, you can: 1. Find some natural mechanism which would cause these animals to migrate such long distances without leaving traces anywhere in between, or migrating to other faraway places. *or* 2. Point out that many other migratory patterns were also possible, of which we happened to get one. This would be a legitimate answer to the question "What are the odds of the kangaroos winding up in Australia and the flies in Hawaii, as opposed to vice versa?" You could reply that each of these was possible, but we happened to wind up with our particular pattern. However, the question being asked is more along the lines of "Why didn't the kangaroos leave any traces on the mainland? Why didn't the kangaroos also wind up on Hawaii? Ditto for the flies, wombats, etc. etc." In other words, the probability of all members of one species migrating to one particular isolated place, *wherever it is*, without going anywhere else and without leaving any traces where they started out or along the way, seems very small. So for each individual isolated species we are talking about a very improbable event. And when you also consider how many of these unique species there are, how there are some in almost every isolated habitat, and how the pattern of all these isolated species fits well with evolution (as I mentioned in the first question), it seems to me that you get a pretty strong piece of evidence favoring evolution. Isaac Dimitrovsky