It is pretty brazen to take your description whether it is right or wrong and say that is all there is to it. For one, you just gave a hopelessly vague description of any processes that might be involved. In addition, the actual phenomenon of consciousness is not really addressed at all. Even the MIT professors tend to steer clear of this question so I view anyone that claims to have the answer with great suspicion unless they have the theoretical framework to back it up. That just isn’t there.
Your example is to evolution as a magician saying “your card is the ace of spades” is to mindreading.
As you point out, it’s an old standby but an urban legend nonetheless. Bumblebees can’t glide (which is what the original, back-of-the-envelope calculations [possibly apocryphal] showed), but it’s been understood since at least the '70s how they generate sufficient lift through the creation of eddies at the end of the fore- and back-strokes of their wings. See here and here for a couple of nice explanations.
- I can’t believe that I spelled ‘apocryphal’ correecktly.
Sorry about my delayed response to this thread, which not only addressed an already answered question but also was totally orthogonal to the current discussion. I guess I thought that I had done a recent refresh, but seems like not.
The thing with the dice shows a population evolving due to selective forces.
The analogy with biological evoultion is very broad, and I’m not exactly sure what pedagogical purpose the analogy is supposed to serve. Still, as far as I can tell, the analogy is accurate as far as it goes.
What’s the objection again? For that matter, what do you guys take yourselves to be objecting to exactly?
-FrL-
The magic trick looks like mindreading, but isn’t really mindreading.
So you seem to be saying that the thing with the dice looks like evolution, but isn’t really evolution.
What is this “evolution” which you acknowledge it looks like, but claim it does not exemplify?
Do you mean by “evolution” the same thing yelimS means by it? What does yelimS mean by the term? Is there anything deficient about his/her use of the term? If so, what?
-FrL-
Looking back through the thread, it appears several, perhaps most, people understood his/her intent from the beginning.
Forewent post reading in favor of mind reading, did we? :smack:
-FrL-
One of the big problems with yelimS’ example is that evolution requires that differences be inheritable, which was not the case with dice. A die that has six spots showing is no more likely than any other die to have 6 spots showing the next time it’s rolled, which means the system fails one of the essential criteria for evolution. If there are traits which are more advantageous to their hosts than not, but they do not get or cannot be passed down, evolution does not occur.
I understand that biological evolution by natural selection in fact procedes as it does in part because of the heritability of traits. But it is not my understanding that the concept of evolution requires that heritability of traits plays this role.
Can you tell me where you got this information, that heritability is essential for evolution?
-FrL-
Seriously? Inheritance of intrinsic (in the case of biological organisms, genetic) characteristics is fundamental to natural selection. If preferred characteristics aren’t passed on to the next generation in some fashion, there’s no “evolution”; all you have is drift and random combination of genes or instructions. Even in nonbiological concepts of evolution–for instance, the concept of “cultural evolution” or conceptual memetics–it’s intrinsic that information about past states and consequences is passed on, albeit in a fashion more akin to Lamarcks transmission of acquired characteristics than preferential selection of inherent qualities.
The dice analogy was a bias toward a statistical distribution of sixes in the Yatzee cup. There’s nothing carried on from one roll to the next–the dice neither know nor care what face they come up with–and unlike biological evolution, there is an ultimate, teleological goal (maximize the sixes) which doesn’t shift or show any competing influences once you’ve achieved the median. This make it, at best, a misleading analogue to natural selection, which is always a moving target. There is no ultimate predator, no top of the chain; everything eats everything else, and as the lion runs faster, so do the wildebeast, each only stopping when they come to an acceptible equilibrium of predation versus starvation.
With regard to biological organisms (save for humans and perhaps, to a very limited extent, a few other mammals) “genetic evolution”, i.e. natural selection is the only way in which evolution affects species. Changes are not “random” in any sense of the word; even if we assume that the input is a random spectrum (i.e. a population is subjected to predation in an entirely unbiased selection process), the result is decidedly non-random, with a bias going toward the animals who are best able to avoid being dinner, either by outrunning the predator or (in the case of herd animals) their herdmates. Even if we restrict the meaning of your statement to genetic mutations, these are not random, either. It’s well understood that some parts of the genome of any given animal are more prone to mutation than other parts, and that strongly entrenched genotypes are, generally speaking, highly resistant to mutation (most likely because they have a multifaceted purpose such that a defect or change would affect so many different developmental characteristics as to render the carrier nonviable).
In the dice example, coming up sixes is the characteristic selected for. But the dice aren’t punished or selected out for coming up some other number. They’ll roll again and again, regardless of which number comes up. The lack of consequences to either the individual die or to the system as a whole, nor any way to alter the rules means that there is no possibility of improvement in the direction of the selective pressure. What you have here is just a biased probability distribution (I think this is an exponential distribution, but someone will no doubt come 'round and correct my statistical misapprehension and/or laziness) rather than the asymmetric, non-zero-sum game that is characteristic of typical natural selection processes.
Stranger
I hope you’uns don’t mind if I ignore the fascinating discussion on evolution and get back to physics?
Quantum gravity has already been mentioned on the previous page, in various forms. We know there has to be some sort of theory of quantum gravity, but we don’t know what it is. The string model (which is not a theory by a long shot, contrary to popular belief) is one of our best guesses, but it’s still not a very good guess (at least, not yet). But this isn’t perhaps such a good example for this thread, since we’ve never yet actually observed any quantum gravity phenomena which need explaining.
My favorite, though, is the question of why the cosmological constant is so small. The cosmological evidence is now pretty much overwhelming that there’s some phenomenon at work in our Universe which causes an accelerating gravitational expansion of space. Effectively, it looks like a force which repels everything from everything else, and which (unlike ordinary gravity) increases in strength at increasing distance. Well, our current models of particle physics predict that there should be a sort of energy associated with the vacuum of spacetime itself, which should behave qualitatively in exactly the manner required to explain the cosmological acceleration. Qualitatively. We can’t precisely predict the exact strength this vacuum energy should have (our particle physics theories are not yet sufficiently complete), but we can estimate it. The problem is, if we take our estimates from particle physics, and compare it with the cosmologically observed value, our estimates are 120 orders of magnitude too high. Not a factor of 120; 120 orders of magnitude. As in, a factor of a hundred million trillion googol too high.
Now, it would be one thing if our estimates predicted one value, and the observed value was exactly zero. That could be easily enough explained: Maybe some of the terms in our estimate should have minus signs, and the negative terms exactly match the positive terms, so they all cancel out exactly. Likewise, if it were only a factor of ten, or a thousand, that wouldn’t be too bad, either: Maybe most of the terms cancel out, but there are a few which don’t. But 120 orders of magnitude? There’s really no good explanation for how things could cancel out that much, but not quite completely.
I wasn’t asking about natural selection, but evolution.
In the rest of your post, you seem to me to continue to confuse the two. There’s evolution, there’s selection, there’s natural selection (which is a phrase denoting a certain process which involves inherited traits, just as you say) and there’s evolution by natural selection. All of these are different concepts, and not all of them involve heritability.
I think you guys are just talking past each other.
-FrL-
Look, anyway, there is an inherited trait being selected for in the dice example. It’s just that the unit carrying this trait isn’t the individual die, but rather, is the set of dice as a whole. The heritable trait is the statistical distribution of numbers amongst the dice. (With just 10 dice, this distribution won’t appear so “heritable” but make it a thousand dice and the analogy becomes more clear.) This trait is inherited from one generation to the next, almost always with some small variance (read “mutation”) where a “generation” can be defined as an instance of the rerolling of at least one die from the group.
If you’re bothered by the fact that, most likely, no generation will have exactly the same statistical distribution as its “ancestor,” (I don’t think you should be, but if you are,) then think of the possible traits as being not just any distribution but rather ranges of distributions.
Anyway, I still don’t think heritability is part of the concept of evolution yelimS is employing, and I do think there’s a perfectly fine use of the term “evolution” to which s/he is adhering in her usage.
-FrL-
In the first paragraph of the above post there should be a comma after ‘…mutation")’
-FrL-
Stranger: You shouldn’t mind so much that a system as simple as in the dice example don’t make a perfect analogy of what goes on with species (at all, I’ll readily admit). The entire point of the example was to show that if a trait is more favorable than others, it tends to prevail regardles of whether or not it is coded into genes. I’ve no objection whatsoever as to the great evolutionary advantages of genes (or memes, or any analogue), but as Frylock says (all excellent posts, by the way), consider the system of dice as a whole and imagine that the larger the sum of all dice, the stronger the system becomes in competition with other such systems. (If rules for competition with other groups-of-dice were implemented, would you be more accepting? If the rules were good enough, I imagine a variant of genes could arise, too) That I’ve decided on these rules instead of using natural rules is completely irrelevant.
As to my extended use of the term evolution, I still believe it’s in line with Dawkins, and he should be enough of an authority there. As stated earlier, I don’t have The Selfish Gene handy, but i think I remember that a key line was something like evolution doesn’t mean survival of the fittest, but survival of the most stable. Apply that to the dice example and I hope you’ll agree calling it evolution isn’t too far a stretch. And it would still be perfectly reasonable to distinguish from what goes on with species by calling that genetic or biological evolution, so I do think my use of the term is a very practical one (and I’m absolutely fine with calling biological evolution just evolution, as long as the debate isn’t specific with regards to the kind of evolution going on).
And how, exactly, do you suppose this trait came about? How do you suppose genes came about? In the long run, they both proved more stable than their adversaries, and thus prevailed. If it’s a stretch calling that evolution, then [insert wisecrack].
Natural selection, mutation - it doesn’t matter. Biological evolution is change over time, which could not occur without heritability.
[unimportant aside]
Following up on yelimS’ curiosity, I rewrote my little routine and found an error. Here are results after 10 million minutes:
1: 4.7613%
2: 9.5266%
3: 14.2940%
4: 19.0557%
5: 23.7952%
6: 28.5672%
[/ua]
So - what verified and commonly observable physical phenomena can science currently not explain?
[/QUOTE]
The method or methods by which pigeons home in unexplained by modern science. While many theories abound, none are considered to have been scientifically ‘proven’.