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. ;
Revue / Journal Title
Poultry science ISSN 0032-5791 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://www.cusf.org [City University of Santa Fe]
----- Original Message -----
From: Ted Carmichael
To: The Friday Morning Applied Complexity Coffee Group
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
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