tag:blogger.com,1999:blog-32636283.post6515861430543424179..comments2023-03-26T03:50:25.501-04:00Comments on David's Secret Blog: Sounds Teleological To MeUnknownnoreply@blogger.comBlogger37125tag:blogger.com,1999:blog-32636283.post-29622416662024886152010-02-02T13:18:50.146-05:002010-02-02T13:18:50.146-05:00Obviously Professor Lowell wasn't trolling for...Obviously Professor Lowell wasn't trolling for a federal grant. Oh, for the good old days.erphttps://www.blogger.com/profile/09826044412670324694noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-2350667960310119542010-02-02T12:04:52.695-05:002010-02-02T12:04:52.695-05:00Sounds like ordinary hindsight bias to me. I can ...Sounds like ordinary hindsight bias to me. I can sympathize with the good professor not wanting to sound like a loon, but the way to handle this sort of thing is the way Percival Lowell (the astronomer who thought he saw canals on Mars) did. You may recall the story where William Hearst is supposed to have sent a telegram to Lowell : PLEASE WIRE 1000 WORDS IS THERE LIFE ON MARS, and Lowell supposedly wired back: NOBODY KNOWS NOBODY KNOWS NOBODY KNOWS, 500 times. That's a lot better than this guy just did.joe shropshirehttps://www.blogger.com/profile/12183662262318452612noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-26607598825384331232010-01-29T17:17:37.126-05:002010-01-29T17:17:37.126-05:00David, there is nothing in the theory that says yo...David, there is nothing in the theory that says you get intelligent life, and so far as we have any evidence of, you can go 3 billion years without even advancing to anything more complicated than a bacterium.<br /><br />However, if you do go toward intelligence, there are (perhaps, we don't know) not an infinite number of ways it could happen. Despite various airy speculations about silicon-based critters floating in hydrogen skies, it seems pretty likely to me that you're going to involve liquid water somehow.<br /><br />We know zip about other kinds of life, but we know a lot about chemistry, and the unusual abilities of H2O and carbon suggest that it would be difficult to get a great deal of complexity from any system that couldn't use those.Harry Eagarhttps://www.blogger.com/profile/04196202758858876402noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-43200178668962659372010-01-28T16:25:09.486-05:002010-01-28T16:25:09.486-05:00Makes the same amount of sense either way.Makes the same amount of sense either way.Hey Skipperhttps://www.blogger.com/profile/10798930502187234974noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-78880410185859801782010-01-28T06:49:07.178-05:002010-01-28T06:49:07.178-05:00Surely you all know I meant "less than one in...Surely you all know I meant "less than one in more than the number of atoms in the universe"? Surely.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32636283.post-21574143500381135312010-01-28T06:24:36.952-05:002010-01-28T06:24:36.952-05:00Once upon a time, a new scientific theory was deve...Once upon a time, a new scientific theory was developed to explain the development of life. It was called Darwinism. It posited that life evolved as a result of a localized survival competition among millions of random genetic mutations. There was no reason for any of these mutations, no direction they led to, no purpose to it all and no reason to pre-suppose any one mutation would prove more beneficial than another--one had to await the outcome of the battle for survival to determine that. Indeed, the proponents of Darwinism became noticeably cranky when anyone suggested anything drove this genetic battle other than the objective survival challenges their hosts encountered in their actual, specific environments.<br /><br />Then, gradually, this theory was repleaced by a completely different theory. Beginning with physics and moving slowly to biology, this new theory posited that the development of life was constrained tightly by many, many universal physical and biochemical laws, the provenance of which no one knew. The more these laws were studied, the more astoundingly fine-tuned they were seen to be, leading to tighter and tighter parameters that led progressively and inexorably to life as we know it today. Not only was the chance emergence of life itself calculated to be one in more of the number of atoms in the universe, gradually it became clear that the major features of life were constrained to the point of near-inevitability, and on a one-way trajectory. It was as if evolution had moved from a spontaneous neighbourhood pick-up game with no rules other than who could outmuscle whom, to a tightly refereed match with a common rulebook so thick, most of the players ended up being ejected from the game by higher authority rather than outmuscled.<br /><br />They called this new theory Darwinism.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32636283.post-46770639293575303122010-01-27T20:59:42.283-05:002010-01-27T20:59:42.283-05:00Peter:
But if we are now moving away from the min...Peter:<br /><br /><i>But if we are now moving away from the minutiae of a million just-so stories and dealing with sweeping universals about evolutionary competition that apply irrespective of local environments (except, of course, when they don't), surely the tautological objection to Darwinism has just gotten a lot stronger.</i><br /><br />The problem with your assertion presuming that it is possible to have both widely varying local environments and sentient life.<br /><br />True, it is nearly impossible to prove a negative. But taking just one premise as given: life requires carbon and widespread liquid water, then local environments simply don't get to vary much. That means all the physical constraints that apply to earth must be similar elsewhere. Reynolds number doesn't matter much for humans, but it certainly did for our very distant aquatic ancestors. Since water is not compressible, a planet's gravity, so long as it is sufficient to retain an atmosphere has (SFAIK) essentially no effect on what body plans work (in an engineering sense) best.<br /><br />Therefore, presuming life was aquatic to start -- and the reasons for that appear hard to avoid -- the body plans available from that beginning are going to be limited in precisely the same ways as on Earth.<br /><br />This is nowhere close to a tautology: the universe of <i>conceivable</i> airplane/bridge/fish designs is far larger than the subset of <i>possible</i> designs. <br /><br />Biomechanical limitations are inescapable. Exoskeletons do not work for anything much larger than will fit in your hand. Why? Can't breath. That upper size limit varies with O2 concentration, but not by a lot. Free oxygen seems to be necessary, which means CO2. Photosynthesis is the only known way to close that circle. But it doesn't provide sufficiently concentrated energy to support a brain. That means a sentient animal has to eat, which means an alimentary canal. Any environment capable of supporting a sentient being will also exhibit scarcity. Etc. <br /><br />Given just one entering assumption, the list of consequent constraints within which evolution must occur gets very long very quickly. <br /><br />It escapes me how teleology is even remotely involved.Hey Skipperhttps://www.blogger.com/profile/10798930502187234974noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-38105351608517711492010-01-27T18:43:16.581-05:002010-01-27T18:43:16.581-05:00David, I didn't mean to say what you said I sa...David, I didn't mean to say what you said I said, I only meant having a tail makes it so difficult to wear designer jeans and high heeled boots.erphttps://www.blogger.com/profile/09826044412670324694noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-52150033087303981212010-01-27T14:09:39.118-05:002010-01-27T14:09:39.118-05:00there are only a finite number of ways to do that....<i>there are only a finite number of ways to do that.</i><br /><br /><i>finite, adj.</i>---One, with a few minor variations in colour and style.<br /><br />David:<br /><br />After years at this game, I find myself completely impervious to accusations I am a total lunkhead about Darwinism, but being caught out in a simple spelling mistake is simply more than I can bear.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32636283.post-2088007411567271162010-01-27T13:35:57.898-05:002010-01-27T13:35:57.898-05:00Harry:
Any theory that says that, no matter what ...Harry:<br /><br />Any theory that says that, no matter what the starting point and after billions of years and millions of random mutations, you will end up with something more or less us (both physically and psychologically) will do until real teleology comes along.Davidhttps://www.blogger.com/profile/16902329503560660425noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-64014598264507137992010-01-27T13:30:46.573-05:002010-01-27T13:30:46.573-05:00Peter:
Though I'm reluctant to correct you at...Peter:<br /><br />Though I'm reluctant to correct you at this point, the proper response was, of course, "Yes, <a href="http://www.youtube.com/watch?v=f7nuZ825nxE" rel="nofollow">and don't call me Shirley</a>."Davidhttps://www.blogger.com/profile/16902329503560660425noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-91135235819360214732010-01-27T12:25:12.719-05:002010-01-27T12:25:12.719-05:00To go back to the heading, whatever it may be, it ...To go back to the heading, whatever it may be, it isn't any more teleological than limiting the number of planes that a crystal can grow in.<br /><br />If -- let's posit -- an intelligent being has to be mobile, then there are only a finite number of ways to do that.Harry Eagarhttps://www.blogger.com/profile/04196202758858876402noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-89318618859768374212010-01-27T12:12:07.447-05:002010-01-27T12:12:07.447-05:00Yeah, it is, but spare me that sniffy "surely...Yeah, it is, but spare me that sniffy "surely" nonsense. You aren't fooling me, I know you had to Google it to make sure yourself.<br /><br />Did you just buy a Park Avenue condo?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32636283.post-47564385569476365502010-01-27T11:58:49.563-05:002010-01-27T11:58:49.563-05:00Surely, it's "Jungle Gym?"Surely, it's "Jungle Gym?"Davidhttps://www.blogger.com/profile/16902329503560660425noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-1620588823873243372010-01-27T11:48:57.306-05:002010-01-27T11:48:57.306-05:00Yes it is a tricky one, because we're not real...Yes it is a tricky one, because we're not really sure any more how important natural selection is compared to other evolutionary factors. So this is as much a question about evolution on earth as speculation about other planets.Brithttps://www.blogger.com/profile/00390560583798960760noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-20220495448746998432010-01-27T11:29:07.410-05:002010-01-27T11:29:07.410-05:00it's not unreasonable to suggest, on the basis...<i>it's not unreasonable to suggest, on the basis of parallel evolution, that on an alien planet very like earth then things would look like earthlings.</i><br /><br />Perhaps, but that doesn't help the argument much, as it is just as reasonable to suggest, based upon the gazillions of random mutations, extinctions and different survival challenges that led us to where we are, that they wouldn't. I suppose that tends to happen when what you are arguing about doesn't exist.<br /><br /><i>As erp suggests, now we're just playing in the sandbox of the Anthropic Principle.</i><br /><br />Damn, that is good, David, and deserves pride of place in the pantheon of erudite, casual and devastating put downs. I'm already working on a few variations to use against unsuspecting leftists who assume conservatives are all stupid:<br /><br /><i>As Harry suggests, now we're just swinging on the Jungle Jim of the cosmological constant;</i><br /><br /><i>As Brit suggests, now we're just frolicking in the wading pool of the multiverse theory</i>;<br /><br /><i>As Skipper suggests, now we're just flailing in the boxing ring of the Fermi Paradox</i><br /><br />I knew all those archives would come in handy one day.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32636283.post-45056909454315767732010-01-27T10:54:14.975-05:002010-01-27T10:54:14.975-05:00But then again, it's not unreasonable to sugge...But then again, it's not unreasonable to suggest, on the basis of parallel evolution, that on an alien planet <i>very like earth</i> then things would look like earthlings. This is what Morris appears to be suggesting, though it's almost, as David always loved to say, trivial.Brithttps://www.blogger.com/profile/00390560583798960760noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-74036055902786250712010-01-27T10:35:04.349-05:002010-01-27T10:35:04.349-05:00As erp suggests, now we're just playing in the...As erp suggests, now we're just playing in the sandbox of the Anthropic Principle.Davidhttps://www.blogger.com/profile/16902329503560660425noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-46563353392215313382010-01-27T10:20:11.347-05:002010-01-27T10:20:11.347-05:00AOG:
I think I understand--sort of. But if we are...AOG:<br /><br />I think I understand--sort of. But if we are now moving away from the minutiae of a million just-so stories and dealing with sweeping universals about evolutionary competition that apply irrespective of local environments (except, of course, when they don't), surely the tautological objection to Darwinism has just gotten a lot stronger.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32636283.post-79839593434167952932010-01-27T09:38:50.073-05:002010-01-27T09:38:50.073-05:00As usual, the great bard says it best and in the f...As usual, the great bard says it best and in the fewest words, "There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy."<br /><br />Our experience is limited to what we can imagine, but there are probably unimaginable (to us) things in a universe as vast as ours? <br /><br />Be fun to be able to explore it.erphttps://www.blogger.com/profile/09826044412670324694noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-56653106843162095762010-01-27T08:48:41.022-05:002010-01-27T08:48:41.022-05:00Bret;
Like gas giant aliens who live in the cloud...Bret;<br /><br />Like gas giant aliens who live in the clouds? They're not going to have two legs :-).<br /><br />I do think that Skipper's probably right, that if you start with a terrestrial planet you'll probably end up with something roughly humanoid.<br /><br />Mr. Burnet;<br /><br />By "work" Skipper means "out compete the other forms". I have intended for years to do a post on this -- I think that the Cambrian explosion followed by a collapse is a nigh inevitable phase of early multi-cellular evolution. The possibility of structurally different aliens comes down to how much luck there is in shake out. Skipper's argument is that because the basic physics are the same, we should expect the same basic designs to win. I have a lot of sympathy for that view, that one has to radically change the environment to get substantively different results.Susan's Husbandhttps://www.blogger.com/profile/02862667802025231163noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-38794191556371140282010-01-27T05:51:35.907-05:002010-01-27T05:51:35.907-05:00Skipper:
I think the reason so few body forms sur...Skipper:<br /><br /><i>I think the reason so few body forms survived the Cambrian is that they are demonstrably superior in engineering terms: they just work better.</i><br /><br />Work better at what, if not at surviving in the local environment? AOG makes the argument that evolution is parsimonious--you evolve what you need to survive and no more--so are we now to assume that two eyes or two legs are equally "needed" throughout the universe? What possible meaning could your word "work" have in this across-the-board analysis?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32636283.post-39368200158421917742010-01-27T00:59:21.203-05:002010-01-27T00:59:21.203-05:00What if gravity were slightly greater or lesser th...What if gravity were slightly greater or lesser than on Earth? What if the atmosphere was a different composition? Wouldn't factors like that have a significant effect on the physiology of life forms?Brethttps://www.blogger.com/profile/15063508651955739056noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-42914072273574723412010-01-27T00:37:47.360-05:002010-01-27T00:37:47.360-05:00Oh, and like erp said, tail optional.Oh, and like erp said, tail optional.Hey Skipperhttps://www.blogger.com/profile/10798930502187234974noreply@blogger.comtag:blogger.com,1999:blog-32636283.post-49870821188442560682010-01-27T00:37:29.601-05:002010-01-27T00:37:29.601-05:00Peter:
No, I'm saying fitness cannot exist in...Peter:<br /><br />No, I'm saying fitness cannot exist independently of physics.<br /><br />Step away from humans for a bit. A bird doesn't get to be any shape: its wings have to be at the side, not top and bottom. The centers of gravity, lift, and drag all have to be very close together. So the design constraints mean anything that functions like a bird is likely to look a lot like a bird, no matter what planet it is on. It can't look like anything else and still fly, because no matter what planet it is on it will still have to deal with gravity, air, and Reynolds number.<br /><br />Despite having followed very different evolutionary paths, birds and bats are structurally similar.<br /><br />Is there some larger reason for two legs? SH has a point -- it could be pure luck of the draw that collapsed the plethora of Cambrian body plans to just a few, so what we see today isn't required, but purely contingent. So we <i>could</i> have ended up with four legs and two arms.<br /><br />However, based on my limited engineering knowledge, I think the reason so few body forms survived the Cambrian is that they are demonstrably superior in engineering terms: they just work better.<br /><br />For a ground dwelling animal larger than insects (I am excluding snakes), four is better than two, and six offers nothing four can't provide. Any technologically capable animal will require at least two hands, but if the starting point is four legs, then the result will likely be bipedal locomotion and two arms.Hey Skipperhttps://www.blogger.com/profile/10798930502187234974noreply@blogger.com