Changes

::::I am trying to get answers to some simple,  basic questions about the experiment.  Is there something wrong with that?

::::I am trying to get answers to some simple,  basic questions about the experiment.  Is there something wrong with that?

::::Also,  the "semantics" -- as you call them -- of "goal" are very important.    A lot of people have the mistaken idea that a goal is necessarily an expected result or is necessarily an intended result.    Just going around telling people that the Cit+ evolution was not a goal can be very misleading.  

::::Also,  the "semantics" -- as you call them -- of "goal" are very important.    A lot of people have the mistaken idea that a goal is necessarily an expected result or is necessarily an intended result.    Just going around telling people that the Cit+ evolution was not a goal can be very misleading.  

:::::If you want to expand the term 'goal' to the point that you including unexpected, unintended results then you rob it of all meaning. By your reasoning, my getting into a fatal car accident is the 'goal' of my driving to the grocery store. If you think that 'goal' is a term of art that describes the entire universe of possible outcomes of an action, you are mistaken. If you want Blount  et al to admit that the emergence of a Cit+ mutant was '''possible''', given the experimental protocol, then I think that you already have your answer: yes. Was it expected? No. Was the experiment designed from the beginning to favor Cit+ mutation over some other pathway? No.--[[User:Brossa|Brossa]] 23:22, 29 June 2008 (EDT)

:::::If you want to expand the term 'goal' to the point that you include unexpected, unintended results then you rob it of all meaning. By your reasoning, my getting into a fatal car accident is the 'goal' of my driving to the grocery store. If you think that 'goal' is a term of art that describes the entire universe of possible outcomes of an action, you are mistaken. If you want Blount  et al to admit that the emergence of a Cit+ mutant was '''possible''', given the experimental protocol, then I think that you already have your answer: yes. Was it expected? No. Was the experiment designed from the beginning to favor Cit+ mutation over some other pathway? No.--[[User:Brossa|Brossa]] 23:22, 29 June 2008 (EDT)

::::''"The purpose of the 'glucose cycling' is to provide the bacteria with an environment that will favor those mutants that are better able to exploit a limited critical resource."''

::::''"The purpose of the 'glucose cycling' is to provide the bacteria with an environment that will favor those mutants that are better able to exploit a limited critical resource."''

::::That statement is too vague.

::::That statement is too vague.

::::''"The glucose cycling does not inherently favor the development of a Cit+ strain any more than it favors other potential solutions to the problem - like secreting a toxin to kill your competitors, or faster reproduction to outbreed them, or photosynthesis, or cannibalism, or what have you."''

::::''"The glucose cycling does not inherently favor the development of a Cit+ strain any more than it favors other potential solutions to the problem - like secreting a toxin to kill your competitors, or faster reproduction to outbreed them, or photosynthesis, or cannibalism, or what have you."''

::::The glucose cycling gives an especially big advantage to Cit+ bacteria because they have something to eat after the glucose supply is exhausted whereas their Cit- neighbors do not.

::::The glucose cycling gives an especially big advantage to Cit+ bacteria because they have something to eat after the glucose supply is exhausted whereas their Cit- neighbors do not.

:::::It gives them '''an''' advantage. It's impossible to predict ahead of time how '''big''' an advantage it is, because instead of being unable to metabolize citrate they may merely be terrible at it. If the Cit- cells are better at glucose metabolism than the Cit+ ones are, they may completely swamp out the Cit+ in the early, glucose-dependent phase. Even if the Cit+ cells continue to grow after the glucose is exhausted, they may never completely outcompete the Cit- cells by the time the next population sample is taken. In fact, this appears to be what has happened, as the experiment has shown that two populations of cells originating from the Ara-3 line have reached a temporary equilibrium: a grows-very-fast-on-glucose Cit- population (10%) and a grows-more-slowly-on-glucose-but-keeps-growing-on-citrate Cit+ population (90%). Using the island analogy: the Cit- folks can eat a candy bar and divide in half a day rather than a day. The Cit+ folks can eat a candy bar and divide once a day, and once the candy bars are gone they can eat the wrappers and divide every day and a half. Now it's just the timing of the helicopter ride that determines whether there are more Cit+ or Cit- people carried to the next island. If the helicopter comes quickly, the Cit- will be favored. If it comes late, the Cit+ will be favored.--[[User:Brossa|Brossa]] 23:26, 29 June 2008 (EDT)  

:::::It gives them '''an''' advantage. It's impossible to predict ahead of time how '''big''' an advantage it is, because instead of being unable to metabolize citrate they may merely be terrible at it. If the Cit- cells are better at glucose metabolism than the Cit+ ones are, they may completely swamp out the Cit+ in the early, glucose-dependent phase. Even if the Cit+ cells continue to grow after the glucose is exhausted, they may never completely outcompete the Cit- cells by the time the next population sample is taken. In fact, this appears to be what has happened, as the experiment has shown that two populations of cells originating from the Ara-3 line have reached a temporary equilibrium: a grows-very-fast-on-glucose Cit- population (10%) and a grows-more-slowly-on-glucose-but-keeps-growing-on-citrate Cit+ population (90%). --[[User:Brossa|Brossa]] 12:05, 30 June 2008 (EDT)

::::''"Citrate is present in the growth medium as a chelating agent and buffer -- it was not added solely to serve as a potential carbon source, although it is one."''

::::''"Citrate is present in the growth medium as a chelating agent and buffer -- it was not added solely to serve as a potential carbon source, although it is one."''

::::Yes,  I know it is there as a chelating agent -- but I also want to know if Cit+ evolution was a goal (again, a goal does not have to be an expected result and can even be an unlikely result) and if favoring Cit+ evolution was a purpose or one of the purposes of the glucose-cycling (I also would like to know if there were other purposes of the glucose-cycling and exactly how any other purposes work).  The fact that Cit+ evolution was observed once previously adds to my hunch that it was a goal.  Also,  the bacteria already had the ability to metabolize citrate and just needed to evolve a way to pass citrate through the cell wall.

::::Yes,  I know it is there as a chelating agent -- but I also want to know if Cit+ evolution was a goal (again, a goal does not have to be an expected result and can even be an unlikely result) and if favoring Cit+ evolution was a purpose or one of the purposes of the glucose-cycling (I also would like to know if there were other purposes of the glucose-cycling and exactly how any other purposes work).  The fact that Cit+ evolution was observed once previously adds to my hunch that it was a goal.  Also,  the bacteria already had the ability to metabolize citrate and just needed to evolve a way to pass citrate through the cell wall.

::::''"You seem to believe that the reason that Lenski is getting acclaim for this research is just that has isolated a strain of E. coli that can metabolize citrate under unusual conditions"''

::::''"You seem to believe that the reason that Lenski is getting acclaim for this research is just that has isolated a strain of E. coli that can metabolize citrate under unusual conditions"''

::::Well,  he is getting a lot of acclaim for it,  isn't he?  The paper has been widely ballyhooed all over the Internet.  The Internet has several articles and hundreds of comments about it.  

::::Well,  he is getting a lot of acclaim for it,  isn't he?  The paper has been widely ballyhooed all over the Internet.  The Internet has several articles and hundreds of comments about it.  

:::::He does not deserve acclaim because he is a farmer who a goose that lays golden eggs, but because he can demonstrate in rough form how the goose came to lay golden eggs when it's grandparents could not. In fact, he has gone back and re-bred the grandparents and gotten golden-egg laying geese again and again, even though none of his other geese, or even the great-grandparents of the golden goose, can breed golden-egg-layers. The real achievement is not having the goose, it's reproducing it against all the odds, and showing that there's something special about the grandparents compared to the greatgrandparents, even though the grandparents appear to be normal. The fact that many folks, including those in the media, can't get past the 'ohmygoshgoldeneggs!!!' phase is not Lenski's fault.--[[User:Brossa|Brossa]] 23:29, 29 June 2008 (EDT)

:::::He does not deserve acclaim because he is a farmer who has a goose that lays golden eggs, but because he can demonstrate in rough form how the goose came to lay golden eggs when it's grandparents could not. In fact, he has gone back and re-bred the grandparents and gotten golden-egg laying geese again and again, even though none of his other geese, or even the great-grandparents of the golden goose, can breed golden-egg-layers. The real achievement is not having the goose, it's reproducing it against all the odds, and showing that there's something special about the grandparents compared to the greatgrandparents, even though the grandparents appear to be normal. The fact that many folks, including those in the media, can't get past the 'ohmygoshgoldeneggs!!!' phase is not Lenski's fault.--[[User:Brossa|Brossa]] 23:29, 29 June 2008 (EDT)

::::''"If you could clearly state what your suspicions are"''

::::''"If you could clearly state what your suspicions are"''

::::Right now I am just trying to understand the experiment. [[User:LarryFarma|LarryFarma]] 20:46, 29 June 2008 (EDT)

::::Right now I am just trying to understand the experiment. [[User:LarryFarma|LarryFarma]] 20:46, 29 June 2008 (EDT)