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 <teds...@gmail.com> 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 < > nickthomp...@earthlink.net> 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 (nthomp...@clarku.edu) >> 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 <teds...@gmail.com> >> *To: *The Friday Morning Applied Complexity Coffee Group<friam@redfish.com> >> *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 >
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