It's kind of a cosmic yolk. On Fri, Jul 9, 2010 at 4:47 PM, Shawn Barr <[email protected]> wrote:
> Ted, > > I'm confused. Why would a genetic algorithm ever select a hen that > produces fewer eggs over a hen that produces more eggs? > > > Shawn > > > On Fri, Jul 9, 2010 at 2:57 PM, Ted Carmichael <[email protected]> wrote: > >> Nick, this is perfect. Thank you! >> >> BTW - the reason for this request is, my advisor and I were asked to write >> a chapter on Complex Adaptive Systems, for a cognitive science textbook. In >> it, I talk briefly about GA, and put this story about the chickens in >> because I thought it was a neat example. >> >> I'll add the references now. Much appreciated. >> >> -t >> >> On Fri, Jul 9, 2010 at 12:28 PM, Nicholas Thompson < >> [email protected]> wrote: >> >>> Ted, >>> >>> Ok. So, if I am correct, this was an actual EXPERIMENT done by two >>> researchers at Indiana University, I think. As I "tell" the "story", it >>> was the practice to use individual selection to identify the most productive >>> chickens, but the egg production method involved crates of nine chickens. >>> The individual selection method inadvertently selected for the most >>> aggressive chickens, so that once you threw them together in crates of nine, >>> it would be like asking nine prom queens to work together in a tug of war. >>> The chickens had to be debeaked or they would kill each other. So, the >>> researchers started selection for the best producing CRATES of chickens. >>> Aggression went down, mortality went down, crate production went up, and >>> debeaking became unnecessary. >>> >>> The experiment is described in Sober and Wilson's UNTO OTHERS or Wilson's >>> EVOLUTION FOR EVERYBODY, which are safely tucked away in my book case 2000 >>> miles away in Santa Fe. Fortunately, it is also described in >>> >>> Dave Wilson's blog >>> http://www.huffingtonpost.com/david-sloan-wilson/truth-and-reconciliation_b_266316.html >>> >>> Here is the original reference: >>> >>> GROUP SELECTION FOR ADAPTATION TO MULTIPLE-HEN CAGES : SELECTION PROGRAM >>> AND DIRECT RESPONSES >>> Auteur(s) / Author(s) >>> MUIR W. >>> M.<http://www.refdoc.fr/?traduire=en&FormRechercher=submit&FormRechercher_Txt_Recherche_name_attr=auteursNom:%20%28MUIR%29>; >>> Revue / Journal Title >>> Poultry >>> science<http://www.refdoc.fr/?traduire=en&FormRechercher=submit&FormRechercher_Txt_Recherche_name_attr=listeTitreSerie:%20%28Poultry%20science%29> >>> *ISSN* >>> 0032-5791<http://www.refdoc.fr/?traduire=en&FormRechercher=submit&FormRechercher_Txt_Recherche_name_attr=identifiantsDoc:%20%280032-5791%29> >>> *CODEN* POSCAL >>> Source / Source >>> 1996, vol. 75, no4, pp. 447-458 [12 page(s) (article)] >>> >>> If you Google "group selection in chickens," you will find lots of other >>> interesting stuff. >>> >>> >>> Let me know if this helps and what you think. >>> >>> N >>> >>> Nicholas S. Thompson >>> Emeritus Professor of Psychology and Ethology, >>> Clark University ([email protected]) >>> http://home.earthlink.net/~nickthompson/naturaldesigns/<http://home.earthlink.net/%7Enickthompson/naturaldesigns/> >>> http://www.cusf.org [City University of Santa Fe] >>> >>> >>> >>> >>> >>> ----- Original Message ----- >>> *From:* Ted Carmichael <[email protected]> >>> *To: *The Friday Morning Applied Complexity Coffee Group<[email protected]> >>> *Sent:* 7/9/2010 5:34:29 AM >>> *Subject:* [FRIAM] Real-world genetic algorithm example... help! >>> >>> Dear all, >>> >>> I'm trying to find reference to a story I read some time ago (a few >>> years, perhaps?), and I'm hoping that either: a) I heard it from someone on >>> this list, or b) someone on this list heard it, too. >>> >>> Anyway, it was a really cool example of a real-world genetic algorithm, >>> having to do with chickens. Traditionally, the best egg-producing chickens >>> were allowed to produce the offspring for future generations. However, >>> these new chickens rarely lived up to their potential. It was thought that >>> maybe there were unknown things going on in the *clusters *of chickens, >>> which represent the actual environment that these chickens are kept in. And >>> that the high producers, when gathered together in these groups, somehow >>> failed to produce as many eggs as expected. >>> >>> So researchers decided to apply the fitness function to *groups *of >>> chickens, rather than individuals. This would perhaps account for social >>> traits that are generally unknown, but may affect how many eggs were laid. >>> In fact, the researchers didn't care what those traits are, only that - >>> whatever they may be - they are preserved in future generations in a way >>> that increased production. >>> >>> And the experiment worked. Groups of chickens that produced the most >>> eggs were preserved, and subsequent generations were much more productive >>> than with the traditional methods. >>> >>> Anyway, that's the story. If anyone can provide a link, I would be very >>> grateful. (As I recall, it wasn't a technical paper, but rather a story in >>> a more accessible venue. Perhaps the NY Times article, or something >>> similar?) >>> >>> Thanks! >>> >>> -Ted >>> >>> >>> ============================================================ >>> FRIAM Applied Complexity Group listserv >>> Meets Fridays 9a-11:30 at cafe at St. John's College >>> lectures, archives, unsubscribe, maps at http://www.friam.org >>> >> >> >> ============================================================ >> FRIAM Applied Complexity Group listserv >> Meets Fridays 9a-11:30 at cafe at St. John's College >> lectures, archives, unsubscribe, maps at http://www.friam.org >> >
============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
