tag:blogger.com,1999:blog-4948885059517209129.post1133330326304958421..comments2023-10-29T08:04:00.488-07:00Comments on Quintessence of Dust: Do ID theorists generate data?Stephen Mathesonhttp://www.blogger.com/profile/05057004085073574659noreply@blogger.comBlogger17125tag:blogger.com,1999:blog-4948885059517209129.post-34527100006547758102008-01-09T00:29:00.000-07:002008-01-09T00:29:00.000-07:00Thanks Stephen for that review. Very entertaining...Thanks Stephen for that review. Very entertaining and informative. Only a small point to make, and I'll make it about the review rather than the blatherings of Wells, as that gives much more chance of contributing to a scientific discourse. And who wants to shoot fish in a barrel? Anyway: the statement that cilia are absent in land plants is false, I think. (If you said "flowering land plants", you would be accurate.) Mosses, liverworts, ferns and their allies, and basal gymnosperms (I'm thinking of cycads) all produce motile sperm, bearing flagella, which are technically cilia. This doesn't affect the point being made, because there are so many other land plants that lack them, but I guess we might as well be accurate. Plus from the point of view of mitotic spindles, the cilia on sperm cells are probably pretty irrelevant. <BR/><BR/>Thanks again for a stimulating review.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-57688409809587155852007-12-07T09:22:00.000-07:002007-12-07T09:22:00.000-07:00Delicious, delightful, deconstruction! Thank you.I...Delicious, delightful, deconstruction! Thank you.<BR/><BR/>I hope that the first hypothesis ever tested on the lag of chromosome arms was just that they were being dragged through a gel with some friction.Monadohttps://www.blogger.com/profile/12523329434641725631noreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-57705739327253493622007-12-07T08:50:00.000-07:002007-12-07T08:50:00.000-07:00Thanks for taking the time to add to your post in ...Thanks for taking the time to add to your post in the comments. I need to do some more reading on this (meaning more reading on the experimental work; I think I can leave a careful reading of Wells' work to others better versed in MTs and the spindle).Ronhttps://www.blogger.com/profile/16773038413499255057noreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-4307552751821761672007-12-07T07:13:00.000-07:002007-12-07T07:13:00.000-07:00Thanks for the clarification. I should probably br...Thanks for the clarification. I should probably brush up on my cell biology.Sparkyhttps://www.blogger.com/profile/10444352252473400411noreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-49225456412181232422007-12-06T22:17:00.000-07:002007-12-06T22:17:00.000-07:00pzed--Nice alias :-) Thanks for the unsurprising ...pzed--<BR/>Nice alias :-) Thanks for the unsurprising report on citation of Wells' paper. I thought of mentioning the impact factor of <I>Rivista</I>, but I don't have data more recent than 2002, and John Lynch already <A HREF="http://scienceblogs.com/strangerfruit/2007/02/revisiting_rivista.php" REL="nofollow">posted that</A>.Stephen Mathesonhttps://www.blogger.com/profile/05057004085073574659noreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-70808393860730117282007-12-06T21:52:00.000-07:002007-12-06T21:52:00.000-07:00Thanks to everyone for your encouragement. My res...Thanks to everyone for your encouragement. My research career is focused on the cytoskeleton, so I've been itching to write something about Wells' paper since it came out. Now that it's done, I can go back to writing about the kind of science where people do experiments.<BR/><BR/>Ron raises a very interesting point about the polar ejection force in plants, noting that land plants do not possess centrioles. Wells makes this a centerpiece of his argument, actually, because he claims that plant cells don't exhibit the polar ejection force. Er...what he actually claims is that "higher plants" do not possess a "pre-anaphase polar ejection force." He provides two citations from the '70s which I haven't read, and a <A HREF="http://www.jcb.org/cgi/content/abstract/132/6/1093" REL="nofollow">much more recent citation</A> which demonstrates that plant cells do exhibit a polar ejection force <I>during anaphase</I>. There are, in fact, significant differences between the mechanisms of chromosome alignment in plant and animal cells, at least up to and including metaphase, and these differences are thought to correlate with the presence/absence of centrosomes (which includes centrioles). And I do think it should be noted that Wells' mechanism is meant to account for the pre-anaphase polar ejection force; he envisions the centriole-turbine vortex shutting down at the onset of anaphase. In other words, Wells' reasoning is fairly sound on this point. <BR/><BR/>This brings me to mwc's question regarding the "purpose" of the polar ejection force. I think my description of the force, by pointing at the lagging arms of moving chromosomes during anaphase, is confusing you and perhaps others. The polar ejection force acts throughout mitosis, not just at anaphase, and its function is to contribute to the gathering of all of the duplicated chromosomes at the middle of the cell. It's a critical function, that plant cells also require but carry out using somewhat different processes.<BR/><BR/>Sorry for all the techie stuff; now perhaps you can see why I didn't include it in the article...Stephen Mathesonhttps://www.blogger.com/profile/05057004085073574659noreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-74499383625225052602007-12-06T14:37:00.000-07:002007-12-06T14:37:00.000-07:00Very nice post, well reasoned and well-written. I ...Very nice post, well reasoned and well-written. I particularly admire the calm and rational tone. It isn't that I don't also enjoy the WTFBBQ sort of post (it is, after all, an almost overwhelming reaction of the scientifically literate to a great deal of ID creationist thought), but stepping out of that fray from time to time is refreshing, and leaves me feeling hopeful. Thank you!Form and Functionhttps://www.blogger.com/profile/12324247838381673885noreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-31318736411951337562007-12-06T14:24:00.000-07:002007-12-06T14:24:00.000-07:00Wells JDo centrioles generate a polar ejection for...Wells J<BR/>Do centrioles generate a polar ejection force? <BR/>RIVISTA DI BIOLOGIA-BIOLOGY FORUM 98 (1): 71-95 JAN-APR 2005<BR/>Times Cited: 0 <BR/>(from Science Citation Index, as of December 6, 2007)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-76846353478907945392007-12-06T11:59:00.000-07:002007-12-06T11:59:00.000-07:00"Cell biologists regularly identify patterns in bi..."Cell biologists regularly identify patterns in biology that make sense through reference to structure-function relationships, and cell biologists are happy to refer to those functions using the vocabulary of design, both literally and metaphorically."<BR/><BR/>I'm glad you wrote this. What ID proponents fail to understand is that natural selection produces what we would call design, although without the necessity or even the implication of a designer.<BR/><BR/>It is, therefore, a fools errand to look around for a "purposeful arrangement of parts" within the 3.5 billion-year end products of evolution and claim you have found God (sorry, an "Intellignet Designer").<BR/><BR/>If it wasn't for ID's obvious find-and-replace relationship with creationism, I wouldn't be opposed to scientific research in this direction.<BR/>Say if someone thought that aliens tinkered with our DNA 6 million years ago to make us fully bipedal and boost our intelligence. Such an "intelligent design" hypothesis could be tested. We could look for alien artifiacts left on Earth, and we could study our own DNA for the discontinuities indicative of genetic engineering. I personally think that, in the end, such a hypotheses would fail, but being testable it would at least stand a chance.<BR/><BR/>Of course IDers are not interested in identifying any particular designer(s), when they designed, by what mechanisms, and to what end, because the less they know, the more each individual IDer can go on believing whatever it is that they always have believed.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-4593479255634189572007-12-06T10:47:00.000-07:002007-12-06T10:47:00.000-07:00really nice blog, guess I-m going to be checking i...really nice blog, guess I-m going to be checking in more often.<BR/><BR/>Comming from Pharyngula *made a few comments on the linked Wells thread there...Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-70573552465919924682007-12-06T09:51:00.000-07:002007-12-06T09:51:00.000-07:00Great post; very informative. Thanks!Great post; very informative. Thanks!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-9168592092972894672007-12-06T08:59:00.000-07:002007-12-06T08:59:00.000-07:00(cross-comment from Pharyngula)What a beautiful pi...(cross-comment from Pharyngula)<BR/><BR/>What a beautiful piece of analysis. Anyone can just call Wells an idiot, and in all honesty that should be enough, but it takes real knowledge and discipline to take something so silly and dissect it so coolly, giving it the benefit of the doubt all the way through the point where you clearly and calmly show why it's utter lunacy. Wells gets the nasty words he deserves, but only at the end once they've really been earned - the lost art of building to a climax.<BR/><BR/>I, for one, am happy the ID-ists are willing to make testable predictions. I've thought for a long time that the ID hypothesis really could do that, in spite of everything, and proponents have just been trying to avoid it. Which makes sense, because here they made a clear prediction and it was flatly wrong. This way ID can be either conclusively invalidated, or forced to revise itself to become closer and closer to reality (e.g. there is a Designer, but He works through evolution) until the God-gap is so small that there'd be no reason to worship anything that fits in it. If re-proving modern science to them step by step is what it takes to bring the fundamentalists into the 21st century, I think that's a good opportunity and we should take it even if it seems like it shouldn't be necessary in an ideal world.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-4555034083771600452007-12-06T08:14:00.000-07:002007-12-06T08:14:00.000-07:00That's an excellent piece. I'm curious whether the...That's an excellent piece. I'm curious whether there is evidence that the polar ejection force serves any purpose. The design principle would imply that centrioles produce the polar ejection force only if the force does something for the cell. If the force is simply an accident, or detrimental, then the hypothesis wouldn't be reasonable (as ID) in the first place.Sparkyhttps://www.blogger.com/profile/10444352252473400411noreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-6666661668256700562007-12-06T05:15:00.000-07:002007-12-06T05:15:00.000-07:00Correct me if I'm wrong, but isn't chromosome beha...Correct me if I'm wrong, but isn't chromosome behavior (at least the bending indicating the "polar ejection force") similar in plants and animals? And plants lack centrioles.... Which would seem to indicate to me that centrioles are dispensable for the polar ejection force. Isn't this idea DOA?Ronhttps://www.blogger.com/profile/16773038413499255057noreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-86229626762251401492007-12-04T08:43:00.000-07:002007-12-04T08:43:00.000-07:00Be careful, Steve. You may find yourself on the DI...Be careful, Steve. You may find yourself on the DI's hit list soon.<BR/><BR/>;)John Farrellhttps://www.blogger.com/profile/18280296574996987228noreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-24569337392356807412007-12-03T14:01:00.000-07:002007-12-03T14:01:00.000-07:00Thanks Martin! Now it's time to move on to someth...Thanks Martin! Now it's time to move on to something better. Reading Wells makes me hungry for actual science.Stephen Mathesonhttps://www.blogger.com/profile/05057004085073574659noreply@blogger.comtag:blogger.com,1999:blog-4948885059517209129.post-87332422832615989652007-12-03T09:59:00.000-07:002007-12-03T09:59:00.000-07:00Thanks. That's a splendid piece of work.Thanks. That's a splendid piece of work.Martin LaBarhttps://www.blogger.com/profile/14629053725732957599noreply@blogger.com