The Evidence of Evolution

oh yeah, and I enjoyed the post very much, praetor.

praetor605:

[1] I think it is worth giving here a quotation form the very first paragraph of David Stove's book Scientific Irrationalism, of which I have already given the details.

Much more is known now than was known fifty years ago [this was written in 1982, when the book first appeared with the title Popper and After: Four Modern Irrationalists. The "four irrationalists" are, according to Stove, Popper himself, Thomas Kuhn, Imre Lakatos and P.K. Feyerabend], and much more was known the than in 1580 [just before Galileo's and Kepler's "revolution" in astronomy and physics]. So there has bee a great accumulation of knowledge in the last four hundred years.

This is an extremely well known fact, which I will refer to as (A). A philosopher, in particular, who did not know it, would be uncommonly ignorant. So a writer whose position inclined him to deny (A), or even made him at all reluctant to admit it, would almost inevitably seem, to the philosophers who read him, to be maintaining something extremely implausible. Such a writer must make that impression, in fact, unless the way he writes effectively disguises the implausibility of his suggestion that (A) is false.

Now, Stove maintains, in his book, that the "three musketeers" of modern epistemology (Kuhn, Lakatos and Feyerabend), and even their "spiritual father" Popper, all, more or less openly, but substantially are advocates of the negation of the validity of (A). IMMO the charge is perfectly justified for the three, whereas, having read Popper's original work of 1934, and the successive books, I believe the charge is not justified for Popper. There is no doubt that, for Popper, scientific hypotheses and even theories never go beyond the stage of conjectures. But I also believe that, through "falsification" and "corroboration" (or, with a more usual word, confirmation), even Popper consider that theories get closer to an underlying truth, in the existence (in not in the attainability) of which Popper definitely and explicitly believes. Popper, as he explicitly calls himself, is a realist, albeit a critical realist.

[2] All I can say to this is that the "computer analogy" should be rather embarrassing for a staunch defender of Theory of Evolution "straight". It becomes, in your court, a clumsy reference to Intelligent Design, methinks …

[3] Yes, the standard time-line for the ecdysozoa, lophotrochozoa, and chordate to divide is 565:525 MYA. The anatomy and the functionality of the eye in Homo and Octopus, though, are so striking as to suggest (heresy!) a possible "front loading" of the "eye plan" in both. Certainly to admit that "photosensitive areas" followed near identical evolution paths by chance may keep our friend Ockham (Occam) happy, but does not make for "inference to best explanation".

[4] I find it most improper to call the DNA "the driving force in evolution", similarly to how I would consider improper to mistake the nervous system for the muscular apparatus. The only "natural", and at the same time rational "motor" of evolution (leaving purposely aside any intervention of an Intelligent "Higher Power"), can only be mutation, which, as we all know, works mostly for worse and not for better.

As for the "several experiments have shown", you are not seriously suggesting that you are still a faithful of the Miller-Urey-Fox "trinity", are you? To believe that chance chemistry easily leads from amino-acids to nucleic acids and proteins requires even more faith than in the other Trinity. Servetus believes that both "trinities" ( "christian" the "chemical") are fictional, anyway.

[5]

As for non-sexual groups, that is tricky. Science looks at these organisms classifies them according to "differences" which are important enough to call for a distinction, which implies that if they were sexual, they would shun other partners. [p605; evidence mine]

The way you describe it, it is not just tricky, it is hilarious: you seem to know the would-be sexual preferences of "non-sexual groups". Honestly!

As for mutations driving evolution, I assumed (perhaps wrongly) that this was implied when I said natural selection drove them apart because it is mutation that causes something to be selected for/against. [p605]

Indeed you "assumed wrongly", because it is not at all implied in what you said. You certainly know that the latest fashion in Evolution, Evolutionary Developmental Biology (or "Evo-Devo") puts all emphasis on "gene regulation" and "gene expression", with "gene mutation" only a vague shadow in the background. This (I am not saying it is your case) is nothing but Lamarckism revisited.

[6]I can only repeat that I did not expect you to engage on my elaborations on metaphysical evolutionism as a vicious form of Gnosticism. And I can add that you are very wise not to tackle the issue.

Servetus really sounds like he knows what he is talking about as well, and this just shows that even among scientists, evolution is not the foregone conclusion that some would have you believe it is. Or I should say the mechanisms or the conclusions drawn from the evidence. As I said before, no is denying the evidence, but only the interpretation of it. To say that DNA similarities is proof of evolution is ludicrous. It is a logical fallacy. I studied logic, I know. What you are saying is that if A is true then B should be true, since B is true therefore A is true. As I said this is a logical fallacy. Here's why. You're saying that DNA similarities among all species is proof of evolution when in fact this leaves out a whole host of other possibilities. Maybe all the DNA is so similar because there is a common creator. What you are saying is that if evolution were true, therefore DNA should be similar across species, DNA is similar across species therefore evolution is true. This is going backwards in the logic and can not be done. There could be other reasons for DNA being similar. And I'm just arguing logically, not scientifically. Your logic would be the same false logic in a doctor saying the following: people who are overweight tend to have higher incidences of high blood pressure, high cholesterol and heart disease therefore if someone has heart disease they are probably overweight. See the logical error here? A leads to B, but B does not necessarily lead to A.

Anyway, just my two cents and maybe it's not even worth that much, but hope I could help a little.

Study some logic praetor and then tell me that. I understand you are well versed in science and the scientific method, but there are a lot of scientists making dubious illogical claims, this being one of them. DNA similarity does not PROVE evolution, it only explains it if it is already assumed that evolution is true.

I think what's most entertaining about perusing this post and the subsequent comments is that praetor605 does not even use the word "God" in his initial post.

Yet the discussion that follows almost exclusively deals with theological matters.

Servetus:

I don't find the computer analogy to be "embarrassing" -- Praetor was illustrating that when you have a logical process of change, you can look at gaps in data/observation and still interpolate what should be there. If a computer 10 years ago had the ability to compute 1,000 calculation/second and a computer today can calculate 10,000 cals/second, then you can interpolate that a computer five years ago computed more than 1,000 and less than 10,000. And if you found a comp from 5yrs ago, and indeed it does 5,000 calcs/sec, then you would probably feel that the initial interpolation had some merit. Both evolution and the improvement of the computer are supposedly logical processes that illustrate the change that occurs to something given time and changes in environment. I don't see the reference to Intelligent Design there.

Also, DNA is the driving force in evolution in the sense that a species genetics, and its change over time, is essentially the process of evolution. You analogy would be more apt as "DNA is to evolution as neurons are to the process of thought" or "muscle fibers are to running". The former object is required for the latter process to occur.

Also, I don't understand your underlying aggression towards Praetor. You indicated earlier that his (her?) tone offended you, yet you continue to write in a tone that comes across (at least to me) as contemptuous or passive-aggressive, at best. We're trying to have a civil debate/discussion. There's no reason for that tone. You shouldn't take it so personally.

Finally, evolution does not interfere with the belief in a higher power. It does make the need for a higher power to exist in order to explain life on this planet unnecessary.

Yes he did scooter, he just referred to God as a higher power. He did use the concept in his original post and since he did and since one can not talk about evolution without also talking about ID and/or creation, then it is a valid topic to discuss. What you are saying would be akin to saying go ahead and talk about politics but don't mention the name Bush.

Well if that is the case, we would be getting into semantics and the definition of God. That is another discussion entirely.

Ok, I am saying that DNA evidence is NOT strong evidence for the theory of evolution. It only is if you already assume evolution to be a fact.

Servetus: I've not studied such things nearly as much as you obviously have, but please allow me to throw in my two cents regarding at least your point #1. It seems to me that in the layman's essay above, Praetor has exluded the mechanism by which a theory can be accepted or discarded by the scientific community. You seem (and please correct me if I'm wrong) to be drawing a distinction between two different mechanisms by which this could take place, 1) by weight of evidence and 2) by some sort of scientific vote. You're putting pressure on him to choose one, but this seems to me like you're pushing pretty hard for a committed response to put him in one of two camps. As this is easily lay-science and nowhere else does it get into the epistemological and ontological subtleties of the scientific discourse, I think it's fair to stick with a lay-science definition: we assume that in most cases, (1) and (2) take place at the same time. Isn't it ok to leave it at that? Most scientists agree to new models because of the overwhelming evidence for them. I'm not sure I see the purpose in splitting theoretical hairs over the exact mechanism at work, especially in Evolution 101. You're dropping all these names and obviously know what you're talking about but it doesn't seem entirely germane to this discussion.

That said, I find the point interesting - I've got a minor in philosophy, I'll count angels on pinheads with you anyday - so why not write a post about it in your own column and open it up for discussion? You obviously have more to say on the subject.

I'm also not entirely sure what you're getting at with your second point - I mean, we can predict the expected size of the sagital crest we can expect to find at any given point along the spectrum. Of course there are margins of error in place, but of course there are. Also, given your example from your first comment, homo gap-ensis isn't a single creature but rather a spectrum, no? We can expect certain charactistics from different points in the gap, so I'd argue that various degrees of Homo Ergaster could indeed have been predicted, couldn't they? Even if we hadn't seen the fossils?

Regarding the octopus/human eye: is your basic argument that they're so similar that they must be working from the same blue print, even though evolution can show and occam can corroborate that this requirement is unnecessary? How is that any different from saying "humans and chimps both have arms, and while we can indeed use evolution to explain this couldn't the design for arms also be frontloaded"? Isn't that, then, the argument for creationism which, stated in its simplest terms, goes something like "Yeah but evolution could be wrong and maybe god made animals the way they are"?

I'm not gonna touch the other points, I could barely follow the arguments as I'm not so well-versed in Evo-Devo or molecular genetics. Again, I'm not a scientist, I'm an English major with predilictions for pop science and philosophy, so if I have misunderstood or overly simplified any of your claims I apologize.

It's true that DNA doesn't PROVE evolution. Nothing really will. However, DNA comparison does FIT with the theory of evolution. I think Dreamweavr72 (grumble) is right. Evolution has to be the theory/hypothesis and DNA is one of the many (many!) pieces of scientific data that fits the hypothesis. Arguing semantics, evolution is only a theory, and DNA does NOT "only explains it if it is already assumed that evolution is true". We do not assume evolution is 'true'. ... only that it's a theory. Am I being a stickler? Probably, only because the 'theory' terminology is so important in these discussions.

(@Dreamweavr72: < disclaimer >I only utter a "grumble" because on these types of posts we usually disagree. I'm not saying you're stupid. It's more of an interjection reflecting my surprise that we're on the same side! Good catch on the logic thing!< /disclaimer >)

Even leaving out the question of God, DNA while fitting in with the theory of evolution still does not prove evolution to be true, because there could be other mechanisms. Before we knew that the sun was at the center of our solar system, there were other models which fit the observed data. Ptolemaic for example. But it has been shown by this that just because the data fits the model does not mean that the model is true.

Just because the data fits the model does not mean that the model is therefore true.

Sorry if my long comment just now covered points Praetor covered in 57, it took me a while to write and that post wasn't up yet when I started.

Also, in response to something Dreamweaver just wrote:

He did use the concept in his original post and since he did and since one can not talk about evolution without also talking about ID and/or creation, then it is a valid topic to discuss. What you are saying would be akin to saying go ahead and talk about politics but don't mention the name Bush.

It is a tribute to the mechanisms at play to introduce ID/creationism into the scientific discourse that you can even make a claim like this. ID has absolutely nothing to do with the science behind evolution, so it's entirely possible to have a discussion about evolution without mentioning it. A layperson's explanation of the science of evolution is NOT an invitation to vent all the frustration you may feel about other scientists in other circumstances trying to convince you that god doesn't exist - nothing even remotely similar to that happened.

Praetor did indeed mention religion in his post - he explicitly stated that nothing in evolution "interferes with the existence of a higher power." You've posted 12 of the 64 comments I see in this thread so far and your general theme has been "Don't tell me what I can and can't believe" - but nobody here has tried to do that. You're not contributing to the discourse - in my opinion, and please correct me if I'm wrong, you're simply venting frustration you feel from other discussions of this subject into this forum, thereby increasing his comment count and decreasing his votes/comments ratio as you have done in numerous other threads. I know you're going to see this as a personal attack and I wish you could understand I don't mean it as one, I just wish you'd stay out of threads unless you are going to add to the value of the discussion.

Dream:
I follow your argument about logic. I think I differ from your perspective, though.

I think evolution is logical. Why? Well for one, all the most logical people I know (scientists, mathmaticians, lawyers) believe it and don't find a logical flaw in the genetics argument you describe. If an illogical assumption existed, it would've raised more than one eyebrow, I think.

And two, personally I view it this way: If evolution is not true, what could explain (concretely/logically) the variance in genetics across species? On a scientific level, I think one could conclude that there is probably some relationship between species that led to the varying differences in genetics for different organisms. Now, your point (I think; correct me if I'm wrong) is that this relationship could exist because of several reasons, evolution notwithstanding. But I think evolution explains both the similarities and the differences between each species genetics to such a degree that evolution is the most likely explanation for the genetic map. Other reasons that might lead to these similarities and differences are harder to measure, if not impossible. So, the simplest reason is put forth as the explanation for genetic differences: evolution.

Now, if evolution explains DNA in species, one might ask if that means DNA is evidence for evolution (the whole A go to B but B doesn't neccessarily go to A thing). If the DNA map cannot be (scientifically/logically) explained by any other means, than one might logically conclude that evolution must exist (according to the current body of knowledge and evidence that exists today), since it is a requirement for the DNA map to exist and make sense.

As Praetor has pointed out time and again, and as has been pointed out times innumerable in other threads on this subject, nobody is claiming that anything has "proved evolution to be true." All Praetor is saying is that the evidence so far all fits, and that there were plenty of chances along the way for the evidence not to fit (this instantly disproving evolution) and that not once has it failed.

Also, the Ptolemaic model did not fit the evidence - it couldn't explain, for instance, retrograde motion in the orbit of the planets. It was the church that maintained Ptolemaic ideas and suppressed true ideas all the way until Galileo and the emergence of the Scientific Method. So, astronomy is really a bad thing to bring up in defense of religious interpretation over scientific interpretation of natural events ;)

**I acknowledge that "evolution must exist" is strong language, and maybe a better way to frame it is that the existence of evolution provides the best story that makes sense of the DNA map. If the DNA map doesn't have a better explanation for existence, than its existence provides merit to the idea/theory of evolution.

As Praetor has pointed out time and again, and as has been pointed out times innumerable in other threads on this subject, nobody is claiming that anything has "proved evolution to be true." All Praetor is saying is that the evidence so far all fits, and that there were plenty of chances along the way for the evidence not to fit (this instantly disproving evolution) and that not once has it failed.

Also, the Ptolemaic model did not fit the evidence - it couldn't explain, for instance, retrograde motion in the orbit of the planets. It was the church that maintained Ptolemaic ideas and suppressed true ideas all the way until Galileo and the emergence of the Scientific Method. So, astronomy is really a bad thing to bring up in defense of religious interpretation over scientific interpretation of natural events ;)

Sorry for the double post, I didn't mean to.

Dreamweavr72 writes:
All I'm saying is that if Praetor wants to be an atheist that is fine, but that he can not use science to show why he is an atheist. If God can not be factored into a scientific theory, then leave him out altogether. If you want to be an atheist you have to use philosophy and metaphysics for that, not science.

That's a key point, one that I have been known to say a little differently, to the distress of atheists: I think that atheism is a religion. Science cannot prove the existence of God and science cannot disprove the existence of God. Therefore, to take either position, you must do it on faith. The two extremes are arrived at the same way.

Science is agnostic.

Mykola, you totally have me wrong in this post. I am not venting frustration at all. I think I have been VERY civil. I am trying to have a discussion and a debate here. Is that not what newsvine is for? Once again, THIS is why you and I keep getting into arguments and littering up the posts. Because everytime I disagree with you, YOU take it personally and as if I am attacking someone. I am attacking no one. I have only stated I disagree, stated what I disagree with and why. Please tell me where I have gone wrong. You are really starting to irk me. Everytime I get into a discussion, which no one else has even said they had a problem with me this time, you jump in to jump down my throat basically saying that dissent doesn't belong here. If you don't think this is what you are doing, you really need to take a long hard look at what you wrote. I could care less how many comments I have written. I have been very respectful and I don't remember ever seeing a maximum participation rule. You jump on my case for no reason, then when I argue back, you claim, "calm down dream, no one is attacking you" You are Mykola and I resent it this time. I have been wrong in the past and I have admitted it. In this discussion I have made it a point to make it civil, then you jump in and screw things all up. Just when I was actually starting to have second thoughts about you as well. I was actually starting to like you but I really don't like how you CONTINUOUSLY try to sqauash any dissent. That is what debate is Mykola. Please show me where I have been anything but civil.

general theme has been "Don't tell me what I can and can't believe" - but nobody here has tried to do that.

You need to do some serious re-reading of this comment thread because at no time did I even come close to implying what you just accused me of. Not even close. How am I not adding to the discourse here?? You dont think ID has anything to do with evolution. I say it most definitely does. You can't talk about one without the other. Sorry! I disagree with the mighty Mykola. You are the one who basically keeps saying "Shut up dream, no one wants to hear you, you dont belong here, dont tell us what to believe" I am only trying to have a civil debate. If that is not what you desire, then I suggest YOU go elsewhere.

I really think you are the one that is out of line this time Mykola.

And about Ptolemy, at the time it was first formulated it did in fact explain all the known facts. It wasn't until much later that it was proven false, ultimately so by Galileo. But the point is that at one time in history all the known facts fit the Ptolemaic model.

I am really at a loss as to why you attacked me this time. But don't do it and then say that is not what you are doing. I have been wrong in the past and I admit that. This time I am not in the wrong.

nobody is claiming that anything has "proved evolution to be true."

While this is true, evolution is about as supported as a scientific theory is going to get. It's accepted as fact among experts of the field. So even though technically evolution has not been proved, it might as well be as far as scientists are concerned.

Now if you want to question the scientific community that we've trusted for so long in such important fields, you're certainly entitled to, but in my mind that makes no sense. Wait, that came out sounding wrong. I'm not saying don't ever question a theory, because obviously scientists have been wrong in the past. But to deny what science has deemed as virtual fact based off of nothing doesn't make sense.

LankaFool, I think we can all agree that science does not deal in virtual fact. Theories are not virtual facts.

The explanation for gravity was pretty well accepted till Einstein came along and upset the apple cart with his theories of relativity. Now we know what really causes gravity and it's nothing like magnetism. I could go on and on with these types of examples. To say that science deals in virtual fact is to deny wholesale the scientific method itself. Theories are always open to amendment and also open to discardment(is that a word?). Virtual fact means that that is the last word on the subject and nothing else can ever be said about it. That sounds more like religious belief to me than true science.