Sorry, Glen. I left out a crucial detail. Before "things get tough", they reproduce by cell division. So, each cell has the choice to throw in with the group, or to continue to reproduce by division. This sets up the "group selection problem" because only some of the individuals that form the fruiting body ever get to be spores.
Nick Nicholas Thompson Emeritus Professor of Ethology and Psychology Clark University thompnicks...@gmail.com https://wordpress.clarku.edu/nthompson/ -----Original Message----- From: Friam <friam-boun...@redfish.com> On Behalf Of ? u?l? Sent: Monday, July 6, 2020 4:28 PM To: FriAM <friam@redfish.com> Subject: Re: [FRIAM] The theory of everything I don't know why I inverted the Mach number. [sigh] What do you mean "when things get tough"? Wikipedia says when food is in short supply. But that sounds like the trigger to become social and, once collected, there might be another (set of) trigger(s) to reproduce? Or is it the case that, once together, they will inevitably reproduce? So, 3 collective behaviors reproduce, move, and harden up? I can imagine that the signal(s) to harden up can be more non-local than the signal(s) to reproduce, whatever it(they) might be. On 7/6/20 2:11 PM, thompnicks...@gmail.com wrote: > Speaking of Reynolds numbers? > > A great many years ago I had an undergraduate honors student who wanted to > work with slime molds. These are social single celled organisms that, when > things get tough, flow together to form a stem and a fruiting body. From the > fruiting body are distributed spores for the next generation. Only some small > percentage of the original cells get into the fruiting body, so they pose a > problem of the "group selection" type. We were wondering whether we should > be thinking of fruiting bodies as like dandelions or like burrs. A little > reflection about scale and viscosity suggested that dandelions was a stupid > model. The student devoted some time to mimicking with a probe what would > happen if an ant brushed up against a fruiting body, and found that, indeed, > they were extremely sticky. We were overjoyed. But then the student fell > in love, and I never saw him again. -- ☣ uǝlƃ - .... . -..-. . -. -.. -..-. .. ... -..-. .... . .-. . FRIAM Applied Complexity Group listserv Zoom Fridays 9:30a-12p Mtn GMT-6 bit.ly/virtualfriam un/subscribe http://redfish.com/mailman/listinfo/friam_redfish.com archives: http://friam.471366.n2.nabble.com/ FRIAM-COMIC http://friam-comic.blogspot.com/ - .... . -..-. . -. -.. -..-. .. ... -..-. .... . .-. . FRIAM Applied Complexity Group listserv Zoom Fridays 9:30a-12p Mtn GMT-6 bit.ly/virtualfriam un/subscribe http://redfish.com/mailman/listinfo/friam_redfish.com archives: http://friam.471366.n2.nabble.com/ FRIAM-COMIC http://friam-comic.blogspot.com/
