First off, to bonzer, thanks for setting the record straight regarding the Darwin – Lord Kelvin controversy. I suspected that the history of that debate was a bit more complicated than tomndebb’s version, having read a good deal on the sociology and history of science; one often sees “simplified stories” like this one employed in discussions of this sort to make a point. They generally disintegrate on closer inspection, but I didn’t know enough about this particular story to be able to debunk it.
Regarding this:
Well, I did admit that I was shamelessly hijacking. But hang around, I’m about to eat crow anyway. tomndebb:
You see, this is why I have suspected – up until now – that evolution is really an unfalsifiable theory. The randomness you refer to “immunizes,” as it were, the theory from falsification tests. There exists, in my opinion, a logical gap here: specific traits, such as horses’ teeth, are said to be the result of evolution, and yet evolution theory can never predict the emergence of such traits. Your general observations may support some general conclusion, but fail to demonstrate how evolution can be falsified in relation to a specific hypothesis – such as, for example, "Hypsodont molars are a result of natural selection.”
In addition, all traits, no matter what they may be, can always be explained by the theory – even traits that are opposites of each other. So, for example (as I suggested in a previous thread), some species of dinoflagellates have tails, and others don’t. Both of these outcomes can be explained, in a virtually ad hoc fashion, as responses to evolutionary pressures. In other words, having tails, not having tails, and all of the variations in between can be articulated, given enough ingenuity on the part of the theorist, in terms of adaptive advantages. I know that this is a completely reasonable, understandable aspect of natural selection, and evolutionary theory, but my point is that it plays hell with falsification.
Popper criticized psychoanalysis because virtually any outcome could be explained by the theory. In a passage I’m not able to locate at the moment, he uses the example of a “drowning child,” stating that should a man save the child, psychoanalytic theory could explain it as a case of “sublimation,” but should he choose not save the child, the theory could explain it as a case of “repression”. Because all outcomes were compatible with the theory, psychoanalysis was unfalsifiable:
According to Popper, specific “verifications” only prove that any given case “can be interpreted in the light of the theory.” They go nowhere in determining whether or not a given theory is empirically true.
I submit that Popper’s critique of psychoanalysis can be reasonably applied to evolutionary theory, where such tendencies are also common-place, especially at the work-bench.
However, all of the above is really just my attempt to defend myself for fucking up big time. After having mulled it over all evening, I’ve come to the conclusion that you Diogenes, and cajela are correct, and that I’m wrong. The fossil record does provide us with the possibility of falsifying some significant elements of evolutionary theory. I was malfunctioning because I kept looking for “positive” predictions; but it’s clear to me, upon reflection, that “negative” predictions serve the purpose just as well. In other words, evolutionary theory does predict that we will never observe certain things; thus, were we to observe them, they would falsify the theory.
cajela’s hypothesis – that no bones from modern humans will be found in Jurassic strata – is the best example: simple, elegant, and compelling. It is an observation statement, derived logically from evolutionary theory, that can be potentially falsified. I suspect that if tomorrow we were to discover such a skeleton, evolutionary theory would suffer a serious setback. Since there are potentially hundreds of such hypotheses (no Precambrian penguins, etc), then as far as that point goes, it seems undeniable that the fossil record can serve to falsify the theory. So, unless someone out there has an objection to this line of reasoning that I haven’t thought of, I must retract and state, for the record:
Evolutionary theory is falsifiable, after all.
(No doubt Abe will weep tears of joy when he reads this.)
Having said that, I still think the falsification criterion is baloney.
No, it’s called science. One thing that separates science from psuedo-science is that scientific theories have SCOPE. They purport to take one aspect of something and explain it, without pretending that the explaination is good for absolutely every question. Evolution takes FOR GRANTED the existence of self-reproducing life forms, and this assumption is very clearly stated. So there’s nothing cheaty about it.
I’m surprised you’d make an inacurate statement like that to someone asking fundamental questions about evolution. Surely you meant to say we did not evolve from any existing species of ape. We did, in fact, evolve from an ape species that existed sometime between about 5 and 8 million years ago.
I’ve read the discussion that you and Abe had about falsification, science and etc. I agree with you that theories never can/will have absolute proof. If one wants absolute “truth” one must turn to religion (and give up, or at least restrain, your critical facilities, IMO).
So, what part of “falsification” is baloney? Clearly, given the fact that we’ll never have absolute proof, we seek evidence to convince us that our theory is (close to) correct. Having formed the theory that a coin always turns up heads, we keep looking for instances where it doesn’t. If we never find one, we keep the theory until something better appears. If we DO find a coin that has turned up tails, we must discard or modify our theory. That’s falsification. (Isn’t that a Dean Martin song?)
Sorry to everyone else about the hijack. He started it!
1.) Humans and modern apes both evolved from a common ancestor, but even so, evolution does not mean that an antecedant species must disappear in order for a descendant species to exist. One population of, say, tree frogs, can be isolated from other tree frogs and evolve independently into a new species while the original population of tree frogs stays the same.
I could also point out tha multiple generations of humans obviously coexist. The fact that we have children or grandchildren does not mean that we have to disappear.
2.) I’m not sure what you mean by how old the earth “seems,” but the earth can be reliably dated to 4 billion years. Is that old enough for you?
I’m aware that many creationists try to dispute the age of the earth but trust me, they aren’t refuting anything with science.
3.) A species does not spontaneously arise from its parents. Populations simply change incrementally over time (think of dog or horse breeding and then multiply it by tens of thousands of years). There is no “moment” of speciation. There are mutations which get selected for and find their way into the gene pool for the whole population.
Let’s go back to the tree frogs. Imagine that one our little frogs is born with a mutation of membranes across its armpits. It turns out that this mutation allows the frog to jump further by “gliding” fro tree to tree on its membranes (think flying squirrel). It passes this mutation onto its offspring and eventually the frogs that inherit this gene begin to gain a slight advantage over other frogs in their ability to leap from tree to tree, thus making it easier for them to gather food and avoid predators. Over thousands of years the frogs born with this gene begin to dominate the other frogs and eventually all of the frogs in the population now have this membrane. Some frogs have bigger mebranes than others and that gives them a slight advantage over the frogs with smaller membranes. After a couple of million years of refinement and selection we get a population of “flying” frogs which can leap tremendous distances and can now said to be a different species than those original tree frogs two million years before. At no point in this process was there ever a lack for suitable mates. The progression is so gradual that it never becomes an issue.
The above example is somewhat simplified. It only describes one evolved trait and there would generally be many more as other favorable mutations worked their way into the gene pool, but i hope it helps to illustrate the process a little bit at least.
I’m feeling weird about having posted here. I just can’t fathom creationists. It’s like finding yourself suddenly surrounded by flat earthers, or people who believe TV is full of midgets who peform for you. What can you say in the face of that?
I popped in because I have read about 2/3 of Behe’s book and was very annoyed at being sucked in to buying it. ID as stealth creationism was totally new to me. I was expecting some interesting popular science thing about biochem & metabolic pathways, and maybe “wow, natural selection operates in some other manner at this internal level”. But after 3 or 4 chapters of “we can’t explain this, so god^H a designer must have done it” i was getting really bored and cross. It’s such a stupid argument - obviously if you have a god like that, your god is just going to shrink all the time. Unless you ban science, which they seem to be trying in some bits of the US.
My christian friends are all normal non-fundy types who think that science is all about discovering the universe - which is to them the work of god, but not something that god micromanages. God is some huge mystical presence behind all of natural law; elucidating natural law in no way contradicts that.
Now should I address points? Maybe one or two. Though I’m baffled as to what to say; I suspect I’m speaking sign language to the blind.
About falsification: I think Popperian falsifiability is necessary but not sufficient to define a science. If nothing you say can ever be shown to be wrong, you don’t have a science. You have an art at best, nonsense at worst. But a science is not brought down by a single counter-observation - if there is only one weird thing, the success of the rest will make that into an anomaly. You have to have an explanation that is BETTER before you abandon the original. Like Einstein and Newton. Yes, I’m starting to sound Kuhnian here, and probably i am most comfortable with that as a philosophy of science. Not in the popular mistaken idea of all paradigms being equally valid, though.
So where does that leave my falsifiable predictions? Well obviously they were a very off the cuff set of remarks. To elucidate each of them you could write a book, so no doubt if I clarify, someone will come and pick nits in the bits I didn’t get to.
Let’s start with the “No modern human fossils in dinosaur era rock stata”. Well, if there were one, I would in all honesty NOT assume evolutionary theory was wrong. It would be one weird fact set up against pretty much the whole of biology, physical anthropology, palaeontology, geology & physics. Most likely it would be a hoax.
The main thing I was trying to get at with my examples is that there have been thousands and thousands of scientific experiments and discoveries, all of which make sense if you assume evolution through natural selection. And yet which need not have been so.
It has been said that nothing in biology makes sense except in the light of evolution - it’s the concept that changes it from stamp collecting to physics (bonus points if you know who I’m quoting). And it’s true - any alternate to the theory of evolution has the most enormous amount of ground to cover in predictive and explanatory power. I’ve never seen any plausible suggestions, that’s for sure.
PS: Wow, thanks for the positive remarks, Mr. Svinlesha
Yes, those points about the fossil record are all good. And if there were a GENUINE human jurassic fossil, yes indeed we would have to rethink an enormous amount. So very very much that what I said above remains so. Occam’s razor would lead one to the hoax first (look up Paluxy for an example). The hypotheses of a trapped time traveller and something wrong with our evolutionary models would probably be pretty close together, though.
[QUOTE]
*Originally posted by TVAA *
Actually, that’s an excellent question: was the earlier common ancestor of the apes an ape itself?
I think we can agree that it was ape-like.
QUOTE]
Speculation, of course, but I doubt that the earliest common ancestor of all apes (extinct and extant) could be called an ape. If it were, that species would have to exist in isolation from other primate species, and then evolve, as a single species, into an ape before giving rise to other ape species.
Of course, the fuzzy line between the various biological taxa defy classification. I’d say the question, while interesting, is not really meaningful in a scientific sense.
[aside]
Depends on the taxonomic system used. In a cladistic sense, the ancestor and all descendents would be, by definition, apes. That is, “ape” might be defined as the most recent common ancestor of humans and gibbons, and all its descendents (or, if you want to equate “ape” to “great ape”, substitute orangutans for gibbons). This is, incidently, a “node-based” definition of apes.
[/aside]
I think this is a highly misleading way to describe things: it gives people exactly the wrong idea (oh, you have to wait around for a favorable mutation: that doesn’t seem very plausible!) While sudden favorable mutations may certainly arise in a single individual, they are unlikely to, all by themselves, induce any real change in a population (the change often being swamped by it breeding back into the “normal” population).
It makes more sense to think about it like this: there is a population. In this population, there is considerable variation among individuals along virtually every trait. What natural selection (basically, the “shit happens, deal with it!” engine) does is not wait around for a really great new mutation to pop up, but rather selects from that pool of variation entire SECTIONS of the population that happen to be best adapted to surviving and reproducing in whatever environment the population finds itself in. The NEXT generation still has quite a wide range of variation within it, but because of the influence of its parents, the “pool” of traits is now skewed towards having the traits that proved most successful in the last generation. This process continues on and on, features slowly altering more and more in each generation: traits that seemed pointless or burdensome finding new uses. The reason the process can continue IS because of things like mutation: but only because mutation is what keeps the pool of variation large enough to have a diverse menu of traits. The mutations don’t have to happen at any particular time, and they need not be appreciably “good” or “useful” at all: just different.
A time to rejoice, Svinlesha! However I must note that many of my original arguments (in the older thread) for the falsification of evolutionary theory are very similar to the ones provided in this thread. And I reserve points for talking about reptilian teeth on chickens, primates without thumbs, etc.
Philosophically speaking, the problem with natural selection and falsification is that every living being we know of is subject to natural selection as it competes in its environment; therefore the various characteristics of living beings can be explained by referring to various mechanisms of natural selection, even when the characteristics might be the precise opposite of each other. It’s not necessarily a fallacy (though I think it can be), it’s simply a result of the irremediably immersive nature of the environment.
Nice devil’s advocate questions and great answers, I have enjoyed reading this thread.
OK, vanilla, as a Christian whose knowledge of biology comes mostly from what I remember of what I learned in high school, I’ll give it a shot.
Look at it this way. You have second, third, and presumably fourth cousins, right? Even Creationists would agree that you and I are descended from the same people the Queen of England is, presumably Adam and Noah, right? So, why hasn’t the Queen of England’s family or my family died out? There are still apes for the same reason there is still royalty in England.
This one is the toughest of the three for me to answer. To me, the earth sometimes seems so old it feels like it must have existed for all time. Even the land being formed from the volcanoes in Hawaii is not new-created, only newly exposed. Lake Erie may be young in geologic terms, but the earth beneath it?
OK, now I’m really drawing on my high school biology. If I recall, sexual reproduction goes right down to one-celled animals because swapping genes increases the chance of getting good genes and surviving. Opposite sexes exist quite a long way down on the scale of evolutionary complexity, and I’d say humans haven’t even got the highest degree of complexity or awkwardness – look at peacocks if nothing else! Mating successfully isn’t all that difficult for humans. Unlike most animals, we don’t have to worry about having only a set time when mating is possible, among other things.
When I knit a sweater, I knit it one piece at a time and one stitch at a time within those pieces. When I’ve got the last stitch on the last piece in place, I then assemble those pieces. It may be vain, but when I look at the finished sweater, I am pleased, and I feel an echo of Genesis 1:31, “So it was; and God saw all that he had made and it was very good.” Just as a piece of knitting evolves, stitch by stitch until a completed piece sits before me, so I believe life evolved, step by step until this marvelously diverse world I see before me came into what it is now and will become. To me, the complexity of evolutionary theory gives glory to God, rather than detracts from His Glory.
This post was brought to you by the one-woman Evolution Is Not Anti-Christian Movement. I now return you to your regularly scheduled high-level biological debate.
Well, guys, I’ve been doing some more mulling since my last post, and I hate to tell you, but I’ve got some bad news…
(Already, from the other side of the planet, I can hear Abe’s teeth gnashing and his hair being pulled out by the roots…)
Let me start from the most recent responses and try to work my way back. First off, very nice sentiments, Siege. Can I join your movement? I can sing a bar of “Alice’s Restaurant” if you like.
Next, Abe:
Yea, verily.
While crossing the great wastes of Ardor, they were forced to eat Sir Abe’s minstrels.
And there was much rejoicing.
(yeaa)
In the words of Ali G, “Respect, mon.”
On the other hand, either I was more obtuse then than I am now (and I mean, let’s face it: I’m still pretty obtuse), or you nevertheless failed to provide such a clear cut example as the one that recently caused me changed my mind. But stick around; I’m about to change it back again.
Here’s why, in part:
Alas, Abe! You just made my argument for me. This difficulty in deriving falsifiable observation statements from evolutionary theory (which you outline above) is precisely what led me to argue that the theory isn’t falsifiable in the first place. As you point out, the theory presupposes factors like “chance,” “competition,” “survival of the fittest,” and the “irremediably immersive nature of the environment” (whatever the hell that might be) which, on the one hand, allow us to describe all possible observable outcomes of an assumed evolutionary process in terms of the theory, but, on the other hand, make it impossible to derive specific falsifiable observation statements. Congratulations! In one short paragraph you have concisely summarized those specific characteristics of evolutionary theory that make it unfalsifiable; it falls prey to exactly the same sort of limitations as classical psychoanalytic theory.
Clearly (provided that the above analysis is correct, and that one is a falsificationist a la Popper), one cannot exclude psychoanalysis from the field of science without excluding evolution theory, which shares many of the same weaknesses. This leaves us with one of three possibilities: 1) we must accept that classical psychoanalysis is scientific after all; or, 2) we must abandon the idea that evolutionary theory is scientific; or… 3) we must give up the conceit that the falsification criterion provides us with a useful method of demarcating science from pseudo-science and non-science. May your humble servant suggest that option 3 appears to be the most rational course of action?
I would like to suggest that both Apos’ and Diogenes’ explications of the mechanism of evolution (does anyone see where I’m going with this yet?) provide, paradoxically, excellent examples of my point. While both are imminently logical, scientific explanations of how the evolutionary process works, I can’t think of a single falsifiable observation implied by either one. I am at a loss as to how one might go about falsifying a theoretical assertion such as the following (by Apos):
If you stop and think about it for a second, the above explanation is in fact based on a tautology (as far as I can tell). How do we identify the “traits that proved most successful in the last generation?” Because they’re the ones that survived, silly! But why did they survive? Because they were the most successful, of course! And can literally any trait a creature possesses be reasonably described in terms of the theory, as an evolutionary advantage? You betcha! Having tails is an advantage! Not having tails is an advantage! Bright plumage is an advantage! Camouflage is an advantage! Being big is an advantage! Being little is an advantage! Being medium-sized is an advantage! Having thumbs is an advantage! Not having thumbs is an advantage! Long life-spans are an advantage! Short life spans are an advantage! Living in groups is an advantage! Living alone is an advantage! Having many mates is an advantage! Having only one mate is an advantage! (Etc., ad infinitum.)
No doubt everyone participating in this thread recognizes this “tool-box” approach to explaining natural diversity. If nothing else, it is a quite common feature of nature documentaries and such. Basically, in the face of any sort of characteristic we find in an animal or plant, we pull our “adaptive advantage” tool out of the evolutionary toolbox and employ to explain this otherwise baffling characteristic/ behavior.
To reiterate: I am not arguing that these post hoc explanations are unreasonable, or unscientific (although some of them may be); I’m simply arguing that they are unfalsifiable.
Of course, by now y’all must be wondering how I could possibly being making this argument while having simultaneously admitted that evolutionary theory is falsifiable. I’m not planning to take that statement back, you may be relieved to learn. I just want to modify it a bit. Darwin’s Finch made an important point on page one of this thread:
This ties into one of the really tricky questions surrounding the falsification criterion, which, approximately, goes like this: where, within the theoretical structure, should the criterion be applied? In this case, we have two “components”: pathways and mechanisms. I’m satisfied that cajela’s and tom’s examples of falsifiable observation statements can be derived from evolutionary theory; but they are only relevant, as far as I can tell, to the pathways. I have yet to be convinced, obtuse as I am, that they apply to the posited mechanisms of evolution.
I remain, of course, more than willing to be convinced otherwise. Go to it, Popperians! cajela:
My pleasure. Welcome to boards, by the way!
Working backwards, still:
If we hold ourselves strictly to Popper, then, unless I’m greatly mistaken, the reaction of the scientific community to an instance of falsification isn’t really relevant to the criterion. It is enough that the theory implies observation statements that are potentially falsifiable.
Yes, we appear to be on approximately the same sheet of music. NoCool:
*I’m flattered that you would waste your time listening to me blather on about this stuff.
Well, in a nutshell, the part that claims that “falsifiability, or testability,” is a sufficient criterion for the demarcation between scientific statements and all other statements. For a lot of reasons, such as: the underdetermined relationship between theory and evidence; the difficulty deciding what constitutes a falsification (see the disagreement between Tom, David, and myself, over the falsifiability of ID, as an example); the fact that practically all scientific theories are, at least in part, unfalsifiable (especially once they reach a certain level of abstraction), while, at the same time, many non-scientific theories, such as astrology, for example, are falsifiable; and so on. Many reasons. Can go into more detail in the next couple of posts, if you wish.
(P.S: Cool user name, by the way! ;)) Voyager:
Dude! Wrong answer!
If you’re going to make dogmatic statements about the scientificity of Einstein, it would behoove you to at least get your facts straight. As TVAA correctly pointed out, you’ve mixed two separate experiments. In addition, the discovery that the glitch in Mercury’s orbit might possibly be explicable by means of Einstein’s theory was not Einstein’s own work, but that of a little-known astrophysicist who was playing around with the application of the theory to the movement of the planets.
Actually, the more I think about this the more I think the common ancestor wouldbe an ape. If it weren’t, we’d have to assume that at least two other species (daughter species of the hypothetical ancestral “ape”) evolved into apes independently of each other.
The more interesting question for me is at what point in the human line (after the split from the human/chimp ancestor) do you stop calling a species an ape. But then, I’d be conmfortable with just admitting that humans are, in fact, apes and not something entirely different.
On the contrary, Behe’s arguments contradict each other. He will present a claim that is falsifiable, and then when it is falsified, modify it to make it unfalsifiable so that he can claim victory. To give just one example:
**
I saw Behe directly confronted with such a falsification. He was told that some IC structures were clearly the result of exon shuffling, and exon shuffling is random. There you have it: ID has been falsified.
His response was that ID hasn’t been disproven unless you can show that God isn’t magically manipulating apparently “random” events behind the scenes. There you have it: ID can never be falsified.
I could go on. For example, Behe is using a “Tower of Why” argument, just like anyone who commits the fallacy of argument from ignorance. You can provide evidence to disprove ID in specific cases, but the overall theory as a whole is unfalsifiable, because even if ID falls on its face a million times, Behe can point to IC system # 1,000,001 and claim that science will never, ever explain how it evolved.
He believes that nearly everything in biology is irreducibly complex. For example, he claimed that pretty much all proteins were designed, because their structures are IC. (And he did so using a strawman argument: he assumed that there was no such thing as a neutral mutation, which came as a bit of a surprise to the audience.)
The problem with Mercury had been known since 1859. Einstein published a paper in 1915 rxplaining the discrepancy with relativity. (He actually published a bunch, correcting mistakes.) After several false steps two British expeditions confirmed his prediction. That confirmation was what made relativity big news.
Yes, the position of stars is also displaced due to the sun’s gravity, but I don’t recall this as a critical factor. The main, easy to understand, issue was that Mercury was not where it was supposed to be according to Newtonian laws, and Einstein’s paper gave the answer without needing to add mass to Venus or give Mercury satellites. That made the result understandable by headline writers. The point here is that the overthrowing of supposed scientific laws is not resisted by scientists, if there is enough evidence.
