Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Douglas Roberts
Practically my philosophy of life.

No coincidence that Wally (Dilbert comic strip) is my main hero.

On Mon, Mar 29, 2010 at 6:45 PM, Vladimyr Ivan Burachynsky
wrote:

>  The cunning riders peel off very quickly and work themselves back into
> the pack and try and hang in but out of the inner recycling.
>

FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
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Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Nicholas Thompson
Hugh, 

I think there is something publishable lurking here.  That, and five bucks will 
buy you a cup of coffee in any restaurant in Santa Fe ... but you better hurry. 
 

Nick 



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: Hugh Trenchard 
To: ERIC P. CHARLES;Nicholas Thompson
Cc: Friam@redfish.com
Sent: 3/29/2010 4:58:42 PM 
Subject: Re: [FRIAM] Sperm pelotons; article in Nature


Thanks, Eric.  That puts it nice and succinctly. That said, I take the points 
about how best to characterize "fitness" and will adjust my draft accordingly 
(and I had some chuckles over the lighter responses too). I'll revise it and 
re-send it sometime over the next few days (it might be old news by then, but 
at least it motivates me to keep working on it!).  I've just seen Vladimir 
Burachynsky's post, and will respond to that momentarily too. 

Hugh
- Original Message - 
From: ERIC P. CHARLES 
To: Nicholas Thompson 
Cc: Hugh Trenchard ; Friam@redfish.com 
Sent: Monday, March 29, 2010 10:13 AM
Subject: Re: [FRIAM] Sperm pelotons; article in Nature


But Nick,
Hugh's point is that we DO NOT need trait-group selection to explain the 
clustering sperm. We merely need sperm to swim in the same direction, AND have 
a variety of abilities. Given that alone, Hugh thinks he can prove, sperm will 
cluster based on their swimming abilities (which he calls 'fitness'). Thus I 
(captial 'I') declare that the real empirical question is whether or not 
sperm-in-clusters are more genetically similar than Hugh's model would predict. 
Only if THAT were true, would we conclude that group selection was involved, as 
the authors of the Nature article have claimed. That is, the authors of the 
Nature article have a flawed notion of what would happen by chance if sperm 
were swimming along without 'relatedness' detectors, and hence they have a 
flawed 'null hypothesis', and hence they have a flawed statistical test. 

(This is all in the same sense that Schank's models have convincingly 
demonstrated that the results of so-called 'menstrual synchrony' research are 
exactly what you would expect due to chance. Those who think they showed 
'menstrual synchrony' just have a flawed notion of what happens by chance.)

Eric




On Mon, Mar 29, 2010 12:30 PM, "Nicholas Thompson"  
wrote:

Hugh, 

I yield to no man in my ignorance of subject we are talking about.  However, 
two points: 

The term "genefur" is one I use to remind myself (and anyone who happens to be 
listening) that the common expression, "a gene for",  (as in "a gene for blue 
eyes" or "a gene for prostate cancer" is deeply problematic.  I should probably 
say something with more words, such as, "a gene for peletonizing, whatever the 
hell that might mean."   Although we know that the path from a trait in parents 
to the same trait in an offspring is much more tortured than a Dawkinsian 
argument requires, and that the material basis for parent-offspring is not as 
"atomic" as the expression "a gene for" implies, we continue to need a term for 
a unit of inheritance and "genefur" is a quietly ironic way to speak of units 
of inheritance while acknowledging that that sort of speech is silly.  

As I understand this discussion it has a lot to do with the group/individual 
selection argument.  Think of it this way.  Think of a bike race containing 20 
riders from 5 teams.  Let it be the case that the winning  TEAM  takes down all 
the prize money but that it is shared unequally by members of the team, with 
half taken by the winning rider, a quarter by the second rider, and the an 
eighth by the 3rd rider, and the balance by the fourth, etc.  Now we have set 
up a conflict between group level and individual level success.  

My comments on fitness are only to remind us that "fitness" in a Darwinian 
conversation means winning the race by any means.  In your terms, "fitness" 
means using your resources to produce the maximum output.   Call these 
"fitnessD" and "fitnessT".  One could be "fitT" all by oneself on a stationary 
bike. However, as the scene in Breaking Away demonstrates, there are lots of 
way to be "fitD" without being "FitT".  

I wish we could engage David Sloan Wilson in this discussion, but he is too 
damned busy running around the world being famous and talking about the 
evolution of religion.  Gawd I hate when that happens.  

Nick 



Nicholas S. Thompson
Emeritus Professor of Psychology and Ethology, 
Clark University (nthomp...@clarku.edu)
http://home.earthlink.net/~nickthompson/naturaldesigns/

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Hugh Trenchard
Thanks, Eric.  That puts it nice and succinctly. That said, I take the points 
about how best to characterize "fitness" and will adjust my draft accordingly 
(and I had some chuckles over the lighter responses too). I'll revise it and 
re-send it sometime over the next few days (it might be old news by then, but 
at least it motivates me to keep working on it!).  I've just seen Vladimir 
Burachynsky's post, and will respond to that momentarily too. 

Hugh
  - Original Message - 
  From: ERIC P. CHARLES 
  To: Nicholas Thompson 
  Cc: Hugh Trenchard ; Friam@redfish.com 
  Sent: Monday, March 29, 2010 10:13 AM
  Subject: Re: [FRIAM] Sperm pelotons; article in Nature


  But Nick,
  Hugh's point is that we DO NOT need trait-group selection to explain the 
clustering sperm. We merely need sperm to swim in the same direction, AND have 
a variety of abilities. Given that alone, Hugh thinks he can prove, sperm will 
cluster based on their swimming abilities (which he calls 'fitness'). Thus I 
(captial 'I') declare that the real empirical question is whether or not 
sperm-in-clusters are more genetically similar than Hugh's model would predict. 
Only if THAT were true, would we conclude that group selection was involved, as 
the authors of the Nature article have claimed. That is, the authors of the 
Nature article have a flawed notion of what would happen by chance if sperm 
were swimming along without 'relatedness' detectors, and hence they have a 
flawed 'null hypothesis', and hence they have a flawed statistical test. 

  (This is all in the same sense that Schank's models have convincingly 
demonstrated that the results of so-called 'menstrual synchrony' research are 
exactly what you would expect due to chance. Those who think they showed 
'menstrual synchrony' just have a flawed notion of what happens by chance.)

  Eric




  On Mon, Mar 29, 2010 12:30 PM, "Nicholas Thompson" 
 wrote:

Hugh, 

I yield to no man in my ignorance of subject we are talking about.  
However, two points: 

The term "genefur" is one I use to remind myself (and anyone who happens to 
be listening) that the common expression, "a gene for",  (as in "a gene for 
blue eyes" or "a gene for prostate cancer" is deeply problematic.  I should 
probably say something with more words, such as, "a gene for peletonizing, 
whatever the hell that might mean."   Although we know that the path from a 
trait in parents to the same trait in an offspring is much more tortured than a 
Dawkinsian argument requires, and that the material basis for parent-offspring 
is not as "atomic" as the expression "a gene for" implies, we continue to need 
a term for a unit of inheritance and "genefur" is a quietly ironic way to speak 
of units of inheritance while acknowledging that that sort of speech is silly.  

As I understand this discussion it has a lot to do with the 
group/individual selection argument.  Think of it this way.  Think of a bike 
race containing 20 riders from 5 teams.  Let it be the case that the winning  
TEAM  takes down all the prize money but that it is shared unequally by members 
of the team, with half taken by the winning rider, a quarter by the second 
rider, and the an eighth by the 3rd rider, and the balance by the fourth, etc.  
Now we have set up a conflict between group level and individual level success. 
 

My comments on fitness are only to remind us that "fitness" in a Darwinian 
conversation means winning the race by any means.  In your terms, "fitness" 
means using your resources to produce the maximum output.   Call these 
"fitnessD" and "fitnessT".  One could be "fitT" all by oneself on a stationary 
bike. However, as the scene in Breaking Away demonstrates, there are lots of 
way to be "fitD" without being "FitT".  

I wish we could engage David Sloan Wilson in this discussion, but he is too 
damned busy running around the world being famous and talking about the 
evolution of religion.  Gawd I hate when that happens.  

Nick 



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: Hugh Trenchard 
  To: ERIC P. CHARLES;Nicholas Thompson 
  Cc: friam@redfish.com 
  Sent: 3/29/2010 9:42:09 AM 
  Subject: Re: [FRIAM] Sperm pelotons; article in Nature


  Thanks Eric for taking the time to look through my post.  For Nick's last 
post, I am not entirely sure what a "genefur" is, although it sounds like it is 
a reference to an inherent genetic trait, as you also discuss.

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Nicholas Thompson
Eric, 

That much I figured out.  I need to know more about the structure of cycle 
races.  I thought it was the case that races contained teams and that the team 
that produced a winning rider won the race, even if all the other team members 
died in the effort.  Not true? 

if it IS true than group effects are obviously relevant, 

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: ERIC P. CHARLES 
To: Nicholas Thompson
Cc: Hugh Trenchard; Friam@redfish.com
Sent: 3/29/2010 11:13:31 AM 
Subject: Re: [FRIAM] Sperm pelotons; article in Nature


But Nick,
Hugh's point is that we DO NOT need trait-group selection to explain the 
clustering sperm. We merely need sperm to swim in the same direction, AND have 
a variety of abilities. Given that alone, Hugh thinks he can prove, sperm will 
cluster based on their swimming abilities (which he calls 'fitness'). Thus I 
(captial 'I') declare that the real empirical question is whether or not 
sperm-in-clusters are more genetically similar than Hugh's model would predict. 
Only if THAT were true, would we conclude that group selection was involved, as 
the authors of the Nature article have claimed. That is, the authors of the 
Nature article have a flawed notion of what would happen by chance if sperm 
were swimming along without 'relatedness' detectors, and hence they have a 
flawed 'null hypothesis', and hence they have a flawed statistical test. 

(This is all in the same sense that Schank's models have convincingly 
demonstrated that the results of so-called 'menstrual synchrony' research are 
exactly what you would expect due to chance. Those who think they showed 
'menstrual synchrony' just have a flawed notion of what happens by chance.)

Eric




On Mon, Mar 29, 2010 12:30 PM, "Nicholas Thompson"  
wrote:

Hugh, 

I yield to no man in my ignorance of subject we are talking about.  However, 
two points: 

The term "genefur" is one I use to remind myself (and anyone who happens to be 
listening) that the common expression, "a gene for",  (as in "a gene for blue 
eyes" or "a gene for prostate cancer" is deeply problematic.  I should probably 
say something with more words, such as, "a gene for peletonizing, whatever the 
hell that might mean."   Although we know that the path from a trait in parents 
to the same trait in an offspring is much more tortured than a Dawkinsian 
argument requires, and that the material basis for parent-offspring is not as 
"atomic" as the expression "a gene for" implies, we continue to need a term for 
a unit of inheritance and "genefur" is a quietly ironic way to speak of units 
of inheritance while acknowledging that that sort of speech is silly.  

As I understand this discussion it has a lot to do with the group/individual 
selection argument.  Think of it this way.  Think of a bike race containing 20 
riders from 5 teams.  Let it be the case that the winning  TEAM  takes down all 
the prize money but that it is shared unequally by members of the team, with 
half taken by the winning rider, a quarter by the second rider, and the an 
eighth by the 3rd rider, and the balance by the fourth, etc.  Now we have set 
up a conflict between group level and individual level success.  

My comments on fitness are only to remind us that "fitness" in a Darwinian 
conversation means winning the race by any means.  In your terms, "fitness" 
means using your resources to produce the maximum output.   Call these 
"fitnessD" and "fitnessT".  One could be "fitT" all by oneself on a stationary 
bike. However, as the scene in Breaking Away demonstrates, there are lots of 
way to be "fitD" without being "FitT".  

I wish we could engage David Sloan Wilson in this discussion, but he is too 
damned busy running around the world being famous and talking about the 
evolution of religion.  Gawd I hate when that happens.  

Nick 



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: Hugh Trenchard 
To: ERIC P. CHARLES;Nicholas Thompson 
Cc: friam@redfish.com 
Sent: 3/29/2010 9:42:09 AM 
Subject: Re: [FRIAM] Sperm pelotons; article in Nature


Thanks Eric for taking the time to look through my post.  For Nick's last post, 
I am not entirely sure what a "genefur" is, although it sounds like it is a 
reference to an inherent genetic trait, as you also discuss.

Yes, I agree it will help my argument if I hone i

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Vladimyr Ivan Burachynsky
ers and attempts to keep them close (just how close is
Hugh's problem) In cycling it is possible to dispose of a follower by simply
slowing your pace and letting your back wheel touch the following front
wheel. Such dirty tricks are not uncommon. The follower almost always loses
control. If not, he will return with a major attitude ! In this case the
goal is not to win but to eliminate the opponents.  One has to be careful
when doing this or the falling rider might take out a group of your affinity
clan as well!  On the other hand this may be the function of some  sperm to
eliminate competition from behind. 

 

I will follow your progress Hugh, as you build your model , with  much
enthusiasm. 

 

I just pumped my skinny tires up and hope to do some lazy riding as spring
arrives in Winnipeg. 

 

 

Dr.Vladimyr Ivan Burachynsky

Ph.D.(Civil Eng.), M.Sc.(Mech.Eng.), M.Sc.(Biology)

 

120-1053 Beaverhill Blvd.

Winnipeg, Manitoba

CANADA R2J 3R2 

(204) 2548321  Phone/Fax

 <mailto:vbur...@shaw.ca> vbur...@shaw.ca 

 

 

-Original Message-
From: friam-boun...@redfish.com [mailto:friam-boun...@redfish.com] On Behalf
Of Hugh Trenchard
Sent: March 29, 2010 10:42 AM
To: ERIC P. CHARLES; Nicholas Thompson
Cc: friam@redfish.com
Subject: Re: [FRIAM] Sperm pelotons; article in Nature

 

Thanks Eric for taking the time to look through my post.  For Nick's last
post, I am not entirely sure what a "genefur" is, although it sounds like it
is a reference to an inherent genetic trait, as you also discuss.

 

Yes, I agree it will help my argument if I hone in more closely on what I
mean by fitness, and I will add some description to clarify this. My useage
relates to inherent physical fitness in terms of maximum power output
capacity. That too needs fine-tuning because I refer to "maximum sustainable
output", which is not the same as absolute maximum power output, and I would
need to outline more carefully what this means.  Regardless, I  think there
are ways of testing for the actual power-output capacities of individual
sperm - I have seen references in the literature to testing procedures for
this. 

 

Because I know very little about genetics, for my part I would be treading
dangerously to begin describing the process in a gene-related sense (and I
would not want to get into discussion about chromosomes), but to address the
issue you raise (if I understand it correctly), it would be necessary to
measure the power output of the sperm of individual male mice to determine
the range of their output capacities and/or the sperms' average output. This
is no doubt not easy, but I imagine there would be some sampling size that
would provide an accurate indication of the overall output range. And
certainly one would want clearly to correspond average sperm outputs and
ranges with the genetic descriptions of the various mice tested, but this
could be done according to a replication of the Fisher and Hoesktra
procedures.  It would also be necessary to determine percentages of energy
savings that occur when sperm are coupled (if this does in fact occur).

 

My model assumes that there is a difference in the average power output of
individual males' sperm, whether related or unrelated or of the same species
or not - a difference sufficiently significant to demonstrate that sorting
occurs according to fitness (in the power-output sense) and not according to
some mechanism for identifying the genetic relatedness of the sperm, as the
authors of the Nature article appear to suggest.  The fact that sperm
aggregate indicates coupling and energy savings, which is why (in my view)
the peloton model applies.

 

In terms of chance, it seems to me Fisher and Hoekstra have taken a lot of
care to establish that there is sorting beyond chance, but implicitly
ascribe that sorting to some sensory/perceptual capacity of the sperm to
identify related sperm.  My model begins with their proven result that there
is sorting beyond chance, and asks whether there is some sorting mechanism
involved other than an unidentified mechanism to perceive the location of
related sperm, which is intuitively problematic because (it seems) sperm do
not have a sufficiently developed sensory system (i.e. eyes, ears, or other)
to do this. 

 

My model provides a simpler explanation for the sorting process than the
Hoekstra & Fisher explanation, because, in my model, sorting occurs
according to self-organized energetic principles, and not according to a
perceptual/sensory mechanism, as apparently implied by the authors.  

 

I can see how a basic computer simulation would be helpful as a starting
point for making predictions according to my model, which I see is really my
next step. 

 

Does anyone know how/where one could apply for some funding to resource such
a simulation?  I could develop it myself (and have developed at least one
simulation, but it really needs to be worked through again), but it would

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Pamela McCorduck

This man is a treasure. Yeah, you, Doug.


On Mar 29, 2010, at 2:30 PM, Douglas Roberts wrote:


Gentlemen,

It was certainly not my intention to hijack this thread...

--Doug

On Mon, Mar 29, 2010 at 12:22 PM, Steve Smith   
wrote:

Nick -


Doug,

Clearly you have never looked closely at Sperm under a microscope.

That is not what his middle school science teacher told me!

- Steve



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

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Douglas Roberts
Gentlemen,

It was certainly not my intention to hijack this thread...

--Doug

On Mon, Mar 29, 2010 at 12:22 PM, Steve Smith  wrote:

>  Nick -
>
>  Doug,
>
> Clearly you have never looked closely at Sperm under a microscope.
>
> That is not what his middle school science teacher told me!
>
> - Steve
>
>

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

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Steve Smith




Nick -

  
  
  Doug, 
   
  Clearly you have never looked closely
at Sperm under a microscope. 
  
  

That is not what his middle school science teacher told me!

- Steve





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

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread ERIC P. CHARLES
But Nick,
Hugh's point is that we DO NOT need trait-group selection to explain the
clustering sperm. We merely need sperm to swim in the same direction, AND have
a variety of abilities. Given that alone, Hugh thinks he can prove, sperm will
cluster based on their swimming abilities (which he calls 'fitness'). Thus I
(captial 'I') declare that the real empirical question is whether or not
sperm-in-clusters are more genetically similar than Hugh's model would predict.
Only if THAT were true, would we conclude that group selection was involved, as
the authors of the Nature article have claimed. That is, the authors of the
Nature article have a flawed notion of what would happen by chance if sperm
were swimming along without 'relatedness' detectors, and hence they have a
flawed 'null hypothesis', and hence they have a flawed statistical test. 

(This is all in the same sense that Schank's models have convincingly
demonstrated that the results of so-called 'menstrual synchrony' research are
exactly what you would expect due to chance. Those who think they showed
'menstrual synchrony' just have a flawed notion of what happens by chance.)

Eric




On Mon, Mar 29, 2010 12:30 PM, "Nicholas Thompson" 
wrote:
>
>
>
>>
>>Hugh, 
>> 
>>I yield to no man in my ignorance of subject we are talking about.  However,
two points: 
>> 
>>The term "genefur" is one I use to remind myself (and anyone who happens to
be listening) that the common expression, "a gene for",  (as in "a gene for
blue eyes" or "a gene for prostate cancer" is deeply problematic.  I should
probably say something with more words, such as, "a gene for peletonizing,
whatever the hell that might mean."   Although we know that the path from a
trait in parents to the same trait in an offspring is much more tortured than a
Dawkinsian argument requires, and that the material basis for parent-offspring
is not as "atomic" as the expression "a gene for" implies, we continue to need
a term for a unit of inheritance and "genefur" is a quietly ironic way to speak
of units of inheritance while acknowledging that that sort of speech is silly.  
>> 
>>As I understand this discussion it has a lot to do with the group/individual
selection argument.  Think of it this way.  Think of a bike race containing 20
riders from 5 teams.  Let it be the case that the winning  TEAM  takes down all
the prize money but that it is shared unequally by members of the team, with
half taken by the winning rider, a quarter by the second rider, and the an
eighth by the 3rd rider, and the balance by the fourth, etc.  Now we have set
up a conflict between group level and individual level success.  
>> 
>>My comments on fitness are only to remind us that "fitness" in a Darwinian
conversation means winning the race by any means.  In your terms, "fitness"
means using your resources to produce the maximum output.   Call these
"fitnessD" and "fitnessT".  One could be "fitT" all by oneself on a stationary
bike. However, as the scene in Breaking Away demonstrates, there are lots of
way to be "fitD" without being "FitT".  
>> 
>>I wish we could engage David Sloan Wilson in this discussion, but he is too
damned busy running around the world being famous and talking about the
evolution of religion.  Gawd I hate when that happens.  
>> 
>>Nick 
>> 
>> 
>> 
>>
>>Nicholas S. Thompson
>>Emeritus Professor of Psychology and Ethology, 
>>Clark University (<#>)
>><http://home.earthlink.net/%7Enickthompson/naturaldesigns/>
>>
><http://www.cusf.org> [City University of Santa Fe]
>> 
>> 
>> 
>
>
>> 
>
>>- Original Message - 
>>
>From: Hugh Trenchard 
>>
>To: ERIC P. CHARLES;Nicholas
Thompson
>>
>Cc: friam@redfish.com
>
>>
>Sent: 3/29/2010 9:42:09 AM 
>>
>Subject: Re: [FRIAM] Sperm pelotons; article in Nature
>>
>
>
>>Thanks Eric for taking the time to look through my post.  For Nick's last
post, I am not entirely sure what a "genefur" is, although it sounds like it is
a reference to an inherent genetic trait, as you also discuss.
>>
> 
>>Yes, I agree it will help my argument if I hone in more closely on what I
mean by fitness, and I will add some description to clarify this. My useage
relates to inherent physical fitness in terms of maximum power output capacity.
That too needs fine-tuning because I refer to "maximum sustainable output",
which is not the same as absolute maximum power output, and I would need to
outline more carefully what this means.  Regardless, I  t

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Douglas Roberts
h I see is really my
>> next step.
>>
>> Does anyone know how/where one could apply for some funding to resource
>> such a simulation?  I could develop it myself (and have developed at least
>> one simulation, but it really needs to be worked through again), but it
>> would happen a whole lot faster if I could engage someone more adept at
>> computer modelling than me.
>>
>>
>> - Original Message -
>>
>> *From:* ERIC P. CHARLES 
>> *To:* Nicholas Thompson 
>> *Cc:* Hugh Trenchard  ; friam@redfish.com
>> *Sent:* Saturday, March 27, 2010 2:54 PM
>> *Subject:* Re: [FRIAM] Sperm pelotons; article in Nature
>>
>> Hugh,
>> Very interesting model! One of my doctoral adviser's, Jeffrey Schank has
>> demonstrated repeatedly that scientists are very bad at predicting what
>> 'chance' looks like when trying to do experiments involving synchrony. This
>> seems one of those situations, and the only way around it is modeling.
>>
>> Nick's sarcasm aside, he has a point, and it has to do with some of the
>> flavor text surrounding your model (for geeks of the wrong variety to know
>> what flavor text is, see: http://en.wikipedia.org/wiki/Flavor_text). If I
>> can take a shot at identifying the problem:
>>
>> Rather than looking at 'fitness' as if it were a unified trait, you have
>> created a model that needs some mutli-stage selection language (the better
>> term escapes me at the moment). The reality is that what makes a 'fit' sperm
>> is not necessarily what makes a 'fit' organism. To fix the flavor text of
>> your model, you would need to explicitly recognize that (if the sperm sort,
>> then) the sperm are going to sort based on a similarity in the genes that
>> 'build' the sperm. Their sorting will be completely independent of all the
>> other genes, or of any role that the sperm-building genes might later play
>> as body-building genes. Ignoring chromosomal linkages (which you shouldn't),
>> two sperm could be identical on all the genes important for building sperm,
>> but completely different in terms of all other genes.
>>
>> Your model would thus al! low a much clearer test of the prediction that
>> sperm identify each other in some way. It does so because it provides a
>> vastly improved predicted relatedness due to chance. GIVEN: We would expect
>> sperm to cluster along the race track based on the similarity of certain,
>> specifiable genes. MODEL: If we know the genes important for building sperm,
>> we can model the expected relatedness of sperms within a cluster. IF: Sperm
>> are implementing some weird sort of kin selection mechanism - THEN: we would
>> expect the relatedness to be significantly larger that what our model
>> predicts.
>>
>> Any help?
>>
>> Eric
>>
>>
>> On Sat, Mar 27, 2010 01:36 PM, *"Nicholas Thompson" <
>> nickthomp...@earthlink.net>* wrote:
>>
>> Hugh,
>>
>> Even if it has nothing to do with sperm it is a nifty model.
>>
>> There is an idea lurking here that i dont know whether it plays a covert
>>
>> role in your thinking or not, but what about the fate of a "genefur"
>> peletonizing.
>>
>> My email program is misbehaving and my computer is about to crash so I wont
>> say more, now.
>>
>>  Nick
>>
>>
>> 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: Hugh Trenchard 
>>
>> > To: ; The Friday Morning Applied
>> Complexity
>> Coffee Group 
>>
>> > Date: 3/27/2010 10:54:41 AM
>> > Subject: Re: [FRIAM] Sperm pelotons; article in Nature
>> >
>> > Thanks for taking a peek at my post. Great que!
>>  stions, and they help me to
>> > see how/where my descriptions can be clarified.
>> >
>> > On the paradox part - that is one of the really interesting features of a
>> > peloton: the energy savings effect of drafting narrows the range of
>>
>> fitness
>> > between the strongest and weakest riders.  In contrast, think of a pack
>> of
>> > runners of varying fitness levels.  There is negligible drafting effect
>> -
>> > there is some, esp if running into a headwind, but overall it's small
>>
>> enough
>> 

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Roger Critchlow
Hugh --

I like the analysis very much.  There should be other cases of velocity
sorting in microbiology and perhaps in developmental biology, any place
where cells are potentially crowded and need to get some where.

I think that sustainability for sperm is an oxymoron -- they have fixed food
reserves and run until they succeed or starve.  Fitness is probably the
wrong word, too, you can frame this in terms of individual and group
efficiency:  the "peloton" goes further and gets anywhere sooner than any of
its individuals could do by itself.

So the doggerel version of the proposal would be able to start with:
 "promiscuous peromyscus spermatozoa".

Perhaps Doug can get over his brightly colored spandex fixation and finish
it for us?

-- rec --
**

On Mon, Mar 29, 2010 at 9:42 AM, Hugh Trenchard  wrote:

>  Thanks Eric for taking the time to look through my post.  For Nick's last
> post, I am not entirely sure what a "genefur" is, although it sounds like it
> is a reference to an inherent genetic trait, as you also discuss.
>
> Yes, I agree it will help my argument if I hone in more closely on what I
> mean by fitness, and I will add some description to clarify this. My useage
> relates to inherent physical fitness in terms of maximum power output
> capacity. That too needs fine-tuning because I refer to "maximum sustainable
> output", which is not the same as absolute maximum power output, and I would
> need to outline more carefully what this means.  Regardless, I  think there
> are ways of testing for the actual power-output capacities of individual
> sperm - I have seen references in the literature to testing procedures for
> this.
>
> Because I know very little about genetics, for my part I would be treading
> dangerously to begin describing the process in a gene-related sense (and
> I would not want to get into discussion about chromosomes), but to address
> the issue you raise (if I understand it correctly), it would be necessary to
> measure the power output of the sperm of individual male mice to determine
> the range of their output capacities and/or the sperms' average output. This
> is no doubt not easy, but I imagine there would be some sampling size that
> would provide an accurate indication of the overall output range. And
> certainly one would want clearly to correspond average sperm outputs and
> ranges with the genetic descriptions of the various mice tested, but this
> could be done according to a replication of the Fisher and Hoesktra
> procedures.  It would also be necessary to determine percentages of energy
> savings that occur when sperm are coupled (if this does in fact occur).
>
> My model assumes that there is a difference in the average power output of
> individual males' sperm, whether related or unrelated or of the same species
> or not - a difference sufficiently significant to demonstrate that sorting
> occurs according to fitness (in the power-output sense) and not according to
> some mechanism for identifying the genetic relatedness of the sperm, as the
> authors of the Nature article appear to suggest.  The fact that sperm
> aggregate indicates coupling and energy savings, which is why (in my view)
> the peloton model applies.
>
> In terms of chance, it seems to me Fisher and Hoekstra have taken a lot of
> care to establish that there is sorting beyond chance, but implicitly
> ascribe that sorting to some sensory/perceptual capacity of the sperm to
> identify related sperm.  My model begins with their proven result that there
> is sorting beyond chance, and asks whether there is some
> sorting mechanism involved other than an unidentified mechanism to perceive
> the location of related sperm, which is intuitively problematic because (it
> seems) sperm do not have a sufficiently developed sensory system (i.e. eyes,
> ears, or other) to do this.
>
> My model provides a simpler explanation for the sorting process than the
> Hoekstra & Fisher explanation, because, in my model, sorting occurs
> according to self-organized energetic principles, and not according to a
> perceptual/sensory mechanism, as apparently implied by the authors.
>
> I can see how a basic computer simulation would be helpful as a starting
> point for making predictions according to my model, which I see is really my
> next step.
>
> Does anyone know how/where one could apply for some funding to resource
> such a simulation?  I could develop it myself (and have developed at least
> one simulation, but it really needs to be worked through again), but it
> would happen a whole lot faster if I could engage someone more adept at
> computer modelling than me.
>
>
> - Original Message -
>
> *From:* ERIC P. CHARLES 
> *To:* Nicholas Thompson 
&

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Nicholas Thompson
Doug, 

Clearly you have never looked closely at Sperm under a microscope.  

We have made enormous strides in micro-visualization technology in the last 
generation. 

Nick 

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: Douglas Roberts 
To: The Friday Morning Applied Complexity Coffee Group
Sent: 3/29/2010 9:48:32 AM 
Subject: Re: [FRIAM] Sperm pelotons; article in Nature


Does anybody besides me have problems getting past the term "sperm pelotons"  
without having bizarre mental images of teeny little bicycles, spandex, and 
colorful itty bitty jerseys?



--Doug


On Mon, Mar 29, 2010 at 9:42 AM, Hugh Trenchard  wrote:

Thanks Eric for taking the time to look through my post.  For Nick's last post, 
I am not entirely sure what a "genefur" is, although it sounds like it is a 
reference to an inherent genetic trait, as you also discuss.

Yes, I agree it will help my argument if I hone in more closely on what I mean 
by fitness, and I will add some description to clarify this. My useage relates 
to inherent physical fitness in terms of maximum power output capacity. That 
too needs fine-tuning because I refer to "maximum sustainable output", which is 
not the same as absolute maximum power output, and I would need to outline more 
carefully what this means.  Regardless, I  think there are ways of testing for 
the actual power-output capacities of individual sperm - I have seen references 
in the literature to testing procedures for this. 

Because I know very little about genetics, for my part I would be treading 
dangerously to begin describing the process in a gene-related sense (and I 
would not want to get into discussion about chromosomes), but to address the 
issue you raise (if I understand it correctly), it would be necessary to 
measure the power output of the sperm of individual male mice to determine the 
range of their output capacities and/or the sperms' average output. This is no 
doubt not easy, but I imagine there would be some sampling size that would 
provide an accurate indication of the overall output range. And certainly one 
would want clearly to correspond average sperm outputs and ranges with the 
genetic descriptions of the various mice tested, but this could be done 
according to a replication of the Fisher and Hoesktra procedures.  It would 
also be necessary to determine percentages of energy savings that occur when 
sperm are coupled (if this does in fact occur).

My model assumes that there is a difference in the average power output of 
individual males' sperm, whether related or unrelated or of the same species or 
not - a difference sufficiently significant to demonstrate that sorting occurs 
according to fitness (in the power-output sense) and not according to some 
mechanism for identifying the genetic relatedness of the sperm, as the authors 
of the Nature article appear to suggest.  The fact that sperm aggregate 
indicates coupling and energy savings, which is why (in my view) the peloton 
model applies.

In terms of chance, it seems to me Fisher and Hoekstra have taken a lot of care 
to establish that there is sorting beyond chance, but implicitly ascribe that 
sorting to some sensory/perceptual capacity of the sperm to identify related 
sperm.  My model begins with their proven result that there is sorting beyond 
chance, and asks whether there is some sorting mechanism involved other than an 
unidentified mechanism to perceive the location of related sperm, which is 
intuitively problematic because (it seems) sperm do not have a sufficiently 
developed sensory system (i.e. eyes, ears, or other) to do this. 

My model provides a simpler explanation for the sorting process than the 
Hoekstra & Fisher explanation, because, in my model, sorting occurs according 
to self-organized energetic principles, and not according to a 
perceptual/sensory mechanism, as apparently implied by the authors.  

I can see how a basic computer simulation would be helpful as a starting point 
for making predictions according to my model, which I see is really my next 
step. 

Does anyone know how/where one could apply for some funding to resource such a 
simulation?  I could develop it myself (and have developed at least one 
simulation, but it really needs to be worked through again), but it would 
happen a whole lot faster if I could engage someone more adept at computer 
modelling than me.


- Original Message - 
From: ERIC P. CHARLES 
To: Nicholas Thompson 
Cc: Hugh Trenchard ; friam@redfish.com 
Sent: Saturday, March 27, 2010 2:54 PM
Subject: Re: [FRIAM] Sperm pelotons; article in Nature


Hugh, 
Very interesting model! One of my doctoral adviser's, Jeffrey Schank has 
demonstrated repeatedly that scientists are

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Nicholas Thompson
Hugh, 

I yield to no man in my ignorance of subject we are talking about.  However, 
two points: 

The term "genefur" is one I use to remind myself (and anyone who happens to be 
listening) that the common expression, "a gene for",  (as in "a gene for blue 
eyes" or "a gene for prostate cancer" is deeply problematic.  I should probably 
say something with more words, such as, "a gene for peletonizing, whatever the 
hell that might mean."   Although we know that the path from a trait in parents 
to the same trait in an offspring is much more tortured than a Dawkinsian 
argument requires, and that the material basis for parent-offspring is not as 
"atomic" as the expression "a gene for" implies, we continue to need a term for 
a unit of inheritance and "genefur" is a quietly ironic way to speak of units 
of inheritance while acknowledging that that sort of speech is silly.  

As I understand this discussion it has a lot to do with the group/individual 
selection argument.  Think of it this way.  Think of a bike race containing 20 
riders from 5 teams.  Let it be the case that the winning  TEAM  takes down all 
the prize money but that it is shared unequally by members of the team, with 
half taken by the winning rider, a quarter by the second rider, and the an 
eighth by the 3rd rider, and the balance by the fourth, etc.  Now we have set 
up a conflict between group level and individual level success.  

My comments on fitness are only to remind us that "fitness" in a Darwinian 
conversation means winning the race by any means.  In your terms, "fitness" 
means using your resources to produce the maximum output.   Call these 
"fitnessD" and "fitnessT".  One could be "fitT" all by oneself on a stationary 
bike. However, as the scene in Breaking Away demonstrates, there are lots of 
way to be "fitD" without being "FitT".  

I wish we could engage David Sloan Wilson in this discussion, but he is too 
damned busy running around the world being famous and talking about the 
evolution of religion.  Gawd I hate when that happens.  

Nick 



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: Hugh Trenchard 
To: ERIC P. CHARLES;Nicholas Thompson
Cc: friam@redfish.com
Sent: 3/29/2010 9:42:09 AM 
Subject: Re: [FRIAM] Sperm pelotons; article in Nature


Thanks Eric for taking the time to look through my post.  For Nick's last post, 
I am not entirely sure what a "genefur" is, although it sounds like it is a 
reference to an inherent genetic trait, as you also discuss.

Yes, I agree it will help my argument if I hone in more closely on what I mean 
by fitness, and I will add some description to clarify this. My useage relates 
to inherent physical fitness in terms of maximum power output capacity. That 
too needs fine-tuning because I refer to "maximum sustainable output", which is 
not the same as absolute maximum power output, and I would need to outline more 
carefully what this means.  Regardless, I  think there are ways of testing for 
the actual power-output capacities of individual sperm - I have seen references 
in the literature to testing procedures for this. 

Because I know very little about genetics, for my part I would be treading 
dangerously to begin describing the process in a gene-related sense (and I 
would not want to get into discussion about chromosomes), but to address the 
issue you raise (if I understand it correctly), it would be necessary to 
measure the power output of the sperm of individual male mice to determine the 
range of their output capacities and/or the sperms' average output. This is no 
doubt not easy, but I imagine there would be some sampling size that would 
provide an accurate indication of the overall output range. And certainly one 
would want clearly to correspond average sperm outputs and ranges with the 
genetic descriptions of the various mice tested, but this could be done 
according to a replication of the Fisher and Hoesktra procedures.  It would 
also be necessary to determine percentages of energy savings that occur when 
sperm are coupled (if this does in fact occur).

My model assumes that there is a difference in the average power output of 
individual males' sperm, whether related or unrelated or of the same species or 
not - a difference sufficiently significant to demonstrate that sorting occurs 
according to fitness (in the power-output sense) and not according to some 
mechanism for identifying the genetic relatedness of the sperm, as the authors 
of the Nature article appear to suggest.  The fact that sperm aggregate 
indicates coupling and energy savings, which is why (i

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Douglas Roberts
Does anybody besides me have problems getting past the term "sperm pelotons"
 without having bizarre mental images of teeny little bicycles, spandex, and
colorful itty bitty jerseys?

--Doug

On Mon, Mar 29, 2010 at 9:42 AM, Hugh Trenchard  wrote:

>  Thanks Eric for taking the time to look through my post.  For Nick's last
> post, I am not entirely sure what a "genefur" is, although it sounds like it
> is a reference to an inherent genetic trait, as you also discuss.
>
> Yes, I agree it will help my argument if I hone in more closely on what I
> mean by fitness, and I will add some description to clarify this. My useage
> relates to inherent physical fitness in terms of maximum power output
> capacity. That too needs fine-tuning because I refer to "maximum sustainable
> output", which is not the same as absolute maximum power output, and I would
> need to outline more carefully what this means.  Regardless, I  think there
> are ways of testing for the actual power-output capacities of individual
> sperm - I have seen references in the literature to testing procedures for
> this.
>
> Because I know very little about genetics, for my part I would be treading
> dangerously to begin describing the process in a gene-related sense (and
> I would not want to get into discussion about chromosomes), but to address
> the issue you raise (if I understand it correctly), it would be necessary to
> measure the power output of the sperm of individual male mice to determine
> the range of their output capacities and/or the sperms' average output. This
> is no doubt not easy, but I imagine there would be some sampling size that
> would provide an accurate indication of the overall output range. And
> certainly one would want clearly to correspond average sperm outputs and
> ranges with the genetic descriptions of the various mice tested, but this
> could be done according to a replication of the Fisher and Hoesktra
> procedures.  It would also be necessary to determine percentages of energy
> savings that occur when sperm are coupled (if this does in fact occur).
>
> My model assumes that there is a difference in the average power output of
> individual males' sperm, whether related or unrelated or of the same species
> or not - a difference sufficiently significant to demonstrate that sorting
> occurs according to fitness (in the power-output sense) and not according to
> some mechanism for identifying the genetic relatedness of the sperm, as the
> authors of the Nature article appear to suggest.  The fact that sperm
> aggregate indicates coupling and energy savings, which is why (in my view)
> the peloton model applies.
>
> In terms of chance, it seems to me Fisher and Hoekstra have taken a lot of
> care to establish that there is sorting beyond chance, but implicitly
> ascribe that sorting to some sensory/perceptual capacity of the sperm to
> identify related sperm.  My model begins with their proven result that there
> is sorting beyond chance, and asks whether there is some
> sorting mechanism involved other than an unidentified mechanism to perceive
> the location of related sperm, which is intuitively problematic because (it
> seems) sperm do not have a sufficiently developed sensory system (i.e. eyes,
> ears, or other) to do this.
>
> My model provides a simpler explanation for the sorting process than the
> Hoekstra & Fisher explanation, because, in my model, sorting occurs
> according to self-organized energetic principles, and not according to a
> perceptual/sensory mechanism, as apparently implied by the authors.
>
> I can see how a basic computer simulation would be helpful as a starting
> point for making predictions according to my model, which I see is really my
> next step.
>
> Does anyone know how/where one could apply for some funding to resource
> such a simulation?  I could develop it myself (and have developed at least
> one simulation, but it really needs to be worked through again), but it
> would happen a whole lot faster if I could engage someone more adept at
> computer modelling than me.
>
>
> - Original Message -
>
> *From:* ERIC P. CHARLES 
> *To:* Nicholas Thompson 
> *Cc:* Hugh Trenchard  ; friam@redfish.com
> *Sent:* Saturday, March 27, 2010 2:54 PM
> *Subject:* Re: [FRIAM] Sperm pelotons; article in Nature
>
> Hugh,
> Very interesting model! One of my doctoral adviser's, Jeffrey Schank has
> demonstrated repeatedly that scientists are very bad at predicting what
> 'chance' looks like when trying to do experiments involving synchrony. This
> seems one of those situations, and the only way around it is modeling.
>
> Nick's sarcasm aside, he has a point, and it has to do with some of

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-29 Thread Hugh Trenchard
Thanks Eric for taking the time to look through my post.  For Nick's last post, 
I am not entirely sure what a "genefur" is, although it sounds like it is a 
reference to an inherent genetic trait, as you also discuss.

Yes, I agree it will help my argument if I hone in more closely on what I mean 
by fitness, and I will add some description to clarify this. My useage relates 
to inherent physical fitness in terms of maximum power output capacity. That 
too needs fine-tuning because I refer to "maximum sustainable output", which is 
not the same as absolute maximum power output, and I would need to outline more 
carefully what this means.  Regardless, I  think there are ways of testing for 
the actual power-output capacities of individual sperm - I have seen references 
in the literature to testing procedures for this. 

Because I know very little about genetics, for my part I would be treading 
dangerously to begin describing the process in a gene-related sense (and I 
would not want to get into discussion about chromosomes), but to address the 
issue you raise (if I understand it correctly), it would be necessary to 
measure the power output of the sperm of individual male mice to determine the 
range of their output capacities and/or the sperms' average output. This is no 
doubt not easy, but I imagine there would be some sampling size that would 
provide an accurate indication of the overall output range. And certainly one 
would want clearly to correspond average sperm outputs and ranges with the 
genetic descriptions of the various mice tested, but this could be done 
according to a replication of the Fisher and Hoesktra procedures.  It would 
also be necessary to determine percentages of energy savings that occur when 
sperm are coupled (if this does in fact occur).
 
My model assumes that there is a difference in the average power output of 
individual males' sperm, whether related or unrelated or of the same species or 
not - a difference sufficiently significant to demonstrate that sorting occurs 
according to fitness (in the power-output sense) and not according to some 
mechanism for identifying the genetic relatedness of the sperm, as the authors 
of the Nature article appear to suggest.  The fact that sperm aggregate 
indicates coupling and energy savings, which is why (in my view) the peloton 
model applies.

In terms of chance, it seems to me Fisher and Hoekstra have taken a lot of care 
to establish that there is sorting beyond chance, but implicitly ascribe that 
sorting to some sensory/perceptual capacity of the sperm to identify related 
sperm.  My model begins with their proven result that there is sorting beyond 
chance, and asks whether there is some sorting mechanism involved other than an 
unidentified mechanism to perceive the location of related sperm, which is 
intuitively problematic because (it seems) sperm do not have a sufficiently 
developed sensory system (i.e. eyes, ears, or other) to do this. 

My model provides a simpler explanation for the sorting process than the 
Hoekstra & Fisher explanation, because, in my model, sorting occurs according 
to self-organized energetic principles, and not according to a 
perceptual/sensory mechanism, as apparently implied by the authors.  

I can see how a basic computer simulation would be helpful as a starting point 
for making predictions according to my model, which I see is really my next 
step. 

Does anyone know how/where one could apply for some funding to resource such a 
simulation?  I could develop it myself (and have developed at least one 
simulation, but it really needs to be worked through again), but it would 
happen a whole lot faster if I could engage someone more adept at computer 
modelling than me.


- Original Message - 
  From: ERIC P. CHARLES 
  To: Nicholas Thompson 
  Cc: Hugh Trenchard ; friam@redfish.com 
  Sent: Saturday, March 27, 2010 2:54 PM
  Subject: Re: [FRIAM] Sperm pelotons; article in Nature


  Hugh, 
  Very interesting model! One of my doctoral adviser's, Jeffrey Schank has 
demonstrated repeatedly that scientists are very bad at predicting what 
'chance' looks like when trying to do experiments involving synchrony. This 
seems one of those situations, and the only way around it is modeling. 

  Nick's sarcasm aside, he has a point, and it has to do with some of the 
flavor text surrounding your model (for geeks of the wrong variety to know what 
flavor text is, see: http://en.wikipedia.org/wiki/Flavor_text). If I can take a 
shot at identifying the problem:

  Rather than looking at 'fitness' as if it were a unified trait, you have 
created a model that needs some mutli-stage selection language (the better term 
escapes me at the moment). The reality is that what makes a 'fit' sperm is not 
necessarily what makes a 'fit' organism. To fix the flavor text of your model, 
you would need to ex

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-27 Thread Nicholas Thompson
YIKES!  Eric, please don't encourage anybody to read sarcasm into my message.  
Absolutely none was intended.  

The question I am toying with,  is, does the model work without a "genefur" 
peletonizing?  If you see me leaning toward some conclusion, it would only be 
that if such a gene is lurking in the model, it could only be supported by 
Wilsonian group selection.  Hugh's model could be unpacked as a version of 
trait-group selection.  

But really I havent thought carefully enough about the model to be sarcastic, 
or enthusiastic, either.  

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: ERIC P. CHARLES 
To: Nicholas Thompson
Cc: Hugh Trenchard; friam@redfish.com
Sent: 3/27/2010 3:54:23 PM 
Subject: Re: [FRIAM] Sperm pelotons; article in Nature


Hugh, 
Very interesting model! One of my doctoral adviser's, Jeffrey Schank has 
demonstrated repeatedly that scientists are very bad at predicting what 
'chance' looks like when trying to do experiments involving synchrony. This 
seems one of those situations, and the only way around it is modeling. 

Nick's sarcasm aside, he has a point, and it has to do with some of the flavor 
text surrounding your model (for geeks of the wrong variety to know what flavor 
text is, see: http://en.wikipedia.org/wiki/Flavor_text). If I can take a shot 
at identifying the problem:

Rather than looking at 'fitness' as if it were a unified trait, you have 
created a model that needs some mutli-stage selection language (the better term 
escapes me at the moment). The reality is that what makes a 'fit' sperm is not 
necessarily what makes a 'fit' organism. To fix the flavor text of your model, 
you would need to explicitly recognize that (if the sperm sort, then) the sperm 
are going to sort based on a similarity in the genes that 'build' the sperm. 
Their sorting will be completely independent of all the other genes, or of any 
role that the sperm-building genes might later play as body-building genes. 
Ignoring chromosomal linkages (which you shouldn't), two sperm could be 
identical on all the genes important for building sperm, but completely 
different in terms of all other genes. 

Your model would thus al! low a much clearer test of the prediction that sperm 
identify each other in some way. It does so because it provides a vastly 
improved predicted relatedness due to chance. GIVEN: We would expect sperm to 
cluster along the race track based on the similarity of certain, specifiable 
genes. MODEL: If we know the genes important for building sperm, we can model 
the expected relatedness of sperms within a cluster. IF: Sperm are implementing 
some weird sort of kin selection mechanism - THEN: we would expect the 
relatedness to be significantly larger that what our model predicts. 

Any help?

Eric


On Sat, Mar 27, 2010 01:36 PM, "Nicholas Thompson"  
wrote:

Hugh, Even if it has nothing to do with sperm it is a nifty model.  There is an 
idea lurking here that i dont know whether it plays a covertrole in your 
thinking or not, but what about the fate of a "genefur"peletonizing.  My email 
program is misbehaving and my computer is about to crash so I wontsay more, 
now.  Nick Nicholas S. ThompsonEmeritus 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: Hugh Trenchard 
> To: ; The Friday Morning 
AppliedComplexityCoffee Group > Date: 3/27/2010 10:54:41 AM> 
Subject: Re: [FRIAM] Sperm pelotons; article in Nature>> Thanks for taking a 
peek at my post. Great que!
 stions, and they help me to > see how/where my descriptions can be 
clarified.>> On the paradox part - that is one of the really interesting 
features of a > peloton: the energy savings effect of drafting narrows the 
range offitness > between the strongest and weakest riders.  In contrast, think 
of a packof > runners of varying fitness levels.  There is negligible drafting 
effect - > there is some, esp if running into a headwind, but overall it's 
smallenough > that it can be ignored for this illustration.  Say there are 50 
runners,all > separated incrementally by 1% difference in fitness; say they run 
acouple > of miles. If they all start off slowly at say the max speed of 
theslowest > runner, they can all run in a big group, separated only by 
enoughdistance > between them to keep them from kicking and elbowing each 
other.  As they > pick up speed, the gr!
 oup thins into a line and are separatedincrementally &!
 gt; by d
istances that correspond to their d

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-27 Thread ERIC P. CHARLES
Hugh, 
Very interesting model! One of my doctoral adviser's, Jeffrey Schank has
demonstrated repeatedly that scientists are very bad at predicting what
'chance' looks like when trying to do experiments involving synchrony. This
seems one of those situations, and the only way around it is modeling. 

Nick's sarcasm aside, he has a point, and it has to do with some of the flavor
text surrounding your model (for geeks of the wrong variety to know what flavor
text is, see: <http://en.wikipedia.org/wiki/Flavor_text>). If I can take a shot
at identifying the problem:

Rather than looking at 'fitness' as if it were a unified trait, you have
created a model that needs some mutli-stage selection language (the better term
escapes me at the moment). The reality is that what makes a 'fit' sperm is not
necessarily what makes a 'fit' organism. To fix the flavor text of your model,
you would need to explicitly recognize that (if the sperm sort, then) the sperm
are going to sort based on a similarity in the genes that 'build' the sperm.
Their sorting will be completely independent of all the other genes, or of any
role that the sperm-building genes might later play as body-building genes.
Ignoring chromosomal linkages (which you shouldn't), two sperm could be
identical on all the genes important for building sperm, but completely
different in terms of all other genes. 

Your model would thus allow a much clearer test of the prediction that sperm
identify each other in some way. It does so because it provides a vastly
improved predicted relatedness due to chance. GIVEN: We would expect sperm to
cluster along the race track based on the similarity of certain, specifiable
genes. MODEL: If we know the genes important for building sperm, we can model
the expected relatedness of sperms within a cluster. IF: Sperm are implementing
some weird sort of kin selection mechanism - THEN: we would expect the
relatedness to be significantly larger that what our model predicts. 

Any help?

Eric


On Sat, Mar 27, 2010 01:36 PM, "Nicholas Thompson" 
wrote:
>
Hugh, 
>
>Even if it has nothing to do with sperm it is a nifty model.  
>
>There is an idea lurking here that i dont know whether it plays a covert
>role in your thinking or not, but what about the fate of a "genefur"
>peletonizing.  
>
>My email program is misbehaving and my computer is about to crash so I wont
>say more, now. 
>
> Nick 
>
>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: Hugh Trenchard 
>> To: ; The Friday Morning Applied
>Complexity
>Coffee Group 
>> Date: 3/27/2010 10:54:41 AM
>> Subject: Re: [FRIAM] Sperm pelotons; article in Nature
>>
>> Thanks for taking a peek at my post. Great questions, and they help me to 
>> see how/where my descriptions can be clarified.
>>
>> On the paradox part - that is one of the really interesting features of a 
>> peloton: the energy savings effect of drafting narrows the range of
>fitness 
>> between the strongest and weakest riders.  In contrast, think of a pack
>of 
>> runners of varying fitness levels.  There is negligible drafting effect 
>- 
>> there is some, esp if running into a headwind, but overall it's small
>enough 
>> that it can be ignored for this illustration.  Say there are 50 runners,
>all 
>> separated incrementally by 1% difference in fitness; say they run a
>couple 
>> of miles. If they all start off slowly at say the max speed of the
>slowest 
>> runner, they can all run in a big group, separated only by enough
>distance 
>> between them to keep them from kicking and elbowing each other.  As they 
>> pick up speed, the group thins into a line and are separated
>incrementally 
>> by distances that correspond to their differences in fitness.  In the
>space 
>> of two miles, they all finish individually in a single long line
>according 
>> to their fitness, and it can be predicted accurately where runners will 
>> finish if you know their starting levels of fitness.
>>
>> This is not the case with a peloton.  For example at 25mph, riders can
>save 
>> at least 25% by drafting (approx savings 1%/mph) - all the
>riders who are 
>> within 25% fitness of the fastest rider can ride together even at the max 
>> speed of the strongest rider.   So their fitness levels are effectively 
>> narrowed, and they can all finish together as a group (ie. globally
>coupled 
>> by finishing within drafting range of each other), and so the

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-27 Thread Nicholas Thompson
Hugh, 

Even if it has nothing to do with sperm it is a nifty model.  

There is an idea lurking here that i dont know whether it plays a covert
role in your thinking or not, but what about the fate of a "genefur"
peletonizing.  

My email program is misbehaving and my computer is about to crash so I wont
say more, now. 

 Nick 

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: Hugh Trenchard 
> To: ; The Friday Morning Applied Complexity
Coffee Group 
> Date: 3/27/2010 10:54:41 AM
> Subject: Re: [FRIAM] Sperm pelotons; article in Nature
>
> Thanks for taking a peek at my post. Great questions, and they help me to 
> see how/where my descriptions can be clarified.
>
> On the paradox part - that is one of the really interesting features of a 
> peloton: the energy savings effect of drafting narrows the range of
fitness 
> between the strongest and weakest riders.  In contrast, think of a pack
of 
> runners of varying fitness levels.  There is negligible drafting effect 
- 
> there is some, esp if running into a headwind, but overall it's small
enough 
> that it can be ignored for this illustration.  Say there are 50 runners,
all 
> separated incrementally by 1% difference in fitness; say they run a
couple 
> of miles. If they all start off slowly at say the max speed of the
slowest 
> runner, they can all run in a big group, separated only by enough
distance 
> between them to keep them from kicking and elbowing each other.  As they 
> pick up speed, the group thins into a line and are separated
incrementally 
> by distances that correspond to their differences in fitness.  In the
space 
> of two miles, they all finish individually in a single long line
according 
> to their fitness, and it can be predicted accurately where runners will 
> finish if you know their starting levels of fitness.
>
> This is not the case with a peloton.  For example at 25mph, riders can
save 
> at least 25% by drafting (approx savings 1%/mph) - all the riders who are 
> within 25% fitness of the fastest rider can ride together even at the max 
> speed of the strongest rider.   So their fitness levels are effectively 
> narrowed, and they can all finish together as a group (ie. globally
coupled 
> by finishing within drafting range of each other), and so the paradox. 
Part 
> of the paradox is also that, while fitness levels are effectively
narrowed 
> by drafting, it means, conversely, that a broader range of fitness levels 
> can ride together in a group, which maybe isn't something that is clear
from 
> my initial post (though it is certainly implied).  Also, there are other 
> important things going on in a peloton which precede the sorting of
riders 
> into groups, some of which I see I do need to clarify to make my model 
> clearer.
>
> Of these, particularly important are 1) the occurrence of peloton
rotations, 
> and 2) points of instability when riders are forced into positions where 
> they do not have optimal drafting advantage. Below a certain output 
> threshold, when all drafting riders in a group are sufficiently below max 
> output, riders have sufficient energy to shift relative positions within
the 
> peloton, and in this particular phase, a self-organized rotational
pattern 
> forms whereby riders advance up the peripheries and riders are forced 
> backward down the middle of the peloton. However, instabilities in pace 
> occur along the way, caused by such things as course obstacles, hills
(when 
> lower speeds reduce drafting advantage, but when output may be at least
as 
> high), cross-winds, narrowing of the course, or short anaerobic bursts
among 
> riders at the front - all of which cause splits (i.e. PDR>1 at these 
> points).   In a competitive situation, instabilities occur frequently 
> causing temporary splits at various places in the peloton, but these are 
> often closed when the cause of the instability has ceased.  Sorting thus 
> occurs according to some combination of peloton rotations in which
stronger 
> riders are able to get to the front and the continual splits in the
peloton 
> at points of instability and reintegrations. I would need to develop the 
> model some more to show this as an equation (though I touch on a basic 
> version of it in my Appendix).
>
> For sperm, I don't know what the initial state of the aggregates are when 
> they begin their travels, but I am assuming (perhaps quite incorrectly), 
> that there is some initial phase in which they are mixed (such as
cyclists 
> on a starting line), and then they begin to sort as they increase speed. 
> During the p

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-27 Thread Hugh Trenchard
e as clear as day!


In any event, my aim is really to ask the question - are there energetic and 
coupling principles that allow sperm to end up in groups which otherwise 
appear to have occurred because genetically related sperm can somehow 
identify each other?   I am really only suggesting the existence of some 
dynamics of the sperm aggregations that could be studied for, which don't 
yet appear to have been addressed.


Hugh

- Original Message - 
From: "Nicholas Thompson" 

To: 
Sent: Friday, March 26, 2010 8:04 PM
Subject: Re: [FRIAM] Sperm pelotons; article in Nature



This is fun to think about.  Hopefully, REC will help me:

Is there a paradox here.  let it be the case that sperm sort themselves by
fitness;  let it further be the case that sperm in peletons have an
advantage over sperm that dont.  Isnt it now the case that sperm are no
longer sorting themselves by fitness?

Ok, forget that:  so let be the case that "fitness" is not defined by
fertization probability, but more in the sense of "physical fitness". 
Some
of the sperm go to the gym, and some don't.  Or some are more muscular 
than

others.  So let it be the case that sperm sort themselves by swimming
speed. The more muscular sperm swim side by side and the less muscular
sperm swim side by side.  But wait a minute, other things being equal
wouldnt everybody bet the peleton effect?  Ok,  forget THAT, too.

All these models assume that everbody starts from the same starting point,
right?  Are they  jostling at the starting gate in the prostate as they 
are

mixed with the seminal fluid.  Is there an advantage to being in the first
pulsation?  So f orth.  Wouldnt these factors overwhelm the peleton 
effect?


And, what about the kamakaze sperm, that stick pumps in the spokes of
unrelated sperm as in that unforgettable scene in Breaking Away.

Ok.  Sorry.  Forget the whole thing.  I do so like metaphors.

Nick

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: Hugh Trenchard 
To: The Friday Morning Applied Complexity Coffee Group 


Date: 3/26/2010 8:38:22 PM
Subject: [FRIAM]  Sperm pelotons; article in Nature

On February 12, Roger Critchlow posted a reference to "sperm pelotons",
which inspired me to read the Nature article and to think a bit about how
principles of peloton interactions could be applied to sperm

aggregations.

I've outlined some thoughts below.



__

DRAFT



Applications of a peloton model to sperm aggregration dynamics

An analysis of article: Fisher, H., Hoekstra, H. (2010) Competition

drives

cooperation among closely related sperm of deer mice. Nature. Vol. 463,

11

Feb 801-803

Hugh Trenchard


Abstract

The Nature article by Fisher and Hoekstra suggests that a mechanism

exists

among the sperm of certain species of mice to identify genetic relatives.
The identification mechanism itself is not apparent and, based upon
observations of analogous processes in bicycle pelotons, an alternative
hypothesis is suggested.  There are similarities between bicycle pelotons
and sperm aggregations: they are both competitive dynamical systems, and
there are energy savings mechanisms by which agents couple and facilitate
self-organized aggregate formations.  A model for the division of a

peloton

at critical output levels is shown and suggested as analogous to certain,
but not all, sperm aggregations, and a model for the relative energy
consumption of coupled and non-coupled aggregates is shown, which

suggests

how sub-aggregates may form that are composed of agents within a narrowed
fitness range, and also why the strongest individual agents may not

always

reach the target objective first.  This suggests that no mechanism is
required for the identification of genetic relatives, but that sorting
occurs according to a self-organized metabolic process whereby sperm with
close fitness levels will aggregate.  Sorting among sperm is hypothesized

to

occur at a critical output threshold, and is more likely to occur among
promiscuous species than monogamous species because sperm velocity of
monogamous species may not be high enough to reach the critical sorting
threshold.  Genetically related sperm are more likely to have closer

average

fitness levels, and so will naturally sort into groups composed of
predominantly related sperm. Thus proposed is an alternative framework by
which to analyze the data.
___





Introduction
Fisher and Hoekstra (2010) provide evidence that supports the
hypothesis that sperm identify related sperm, aggregate and cooperate

with

them and, through increased velocity when travelling in aggregations,
provide an advantage to genetically related sperm in advancing one of

their

Re: [FRIAM] Sperm pelotons; article in Nature

2010-03-26 Thread Nicholas Thompson
This is fun to think about.  Hopefully, REC will help me:

Is there a paradox here.  let it be the case that sperm sort themselves by
fitness;  let it further be the case that sperm in peletons have an
advantage over sperm that dont.  Isnt it now the case that sperm are no
longer sorting themselves by fitness? 

Ok, forget that:  so let be the case that "fitness" is not defined by
fertization probability, but more in the sense of "physical fitness".  Some
of the sperm go to the gym, and some don't.  Or some are more muscular than
others.  So let it be the case that sperm sort themselves by swimming
speed. The more muscular sperm swim side by side and the less muscular
sperm swim side by side.  But wait a minute, other things being equal
wouldnt everybody bet the peleton effect?  Ok,  forget THAT, too.  

All these models assume that everbody starts from the same starting point,
right?  Are they  jostling at the starting gate in the prostate as they are
mixed with the seminal fluid.  Is there an advantage to being in the first
pulsation?  So f orth.  Wouldnt these factors overwhelm the peleton effect?

And, what about the kamakaze sperm, that stick pumps in the spokes of
unrelated sperm as in that unforgettable scene in Breaking Away.  

Ok.  Sorry.  Forget the whole thing.  I do so like metaphors. 

Nick   

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: Hugh Trenchard 
> To: The Friday Morning Applied Complexity Coffee Group 
> Date: 3/26/2010 8:38:22 PM
> Subject: [FRIAM]  Sperm pelotons; article in Nature
>
> On February 12, Roger Critchlow posted a reference to "sperm pelotons", 
> which inspired me to read the Nature article and to think a bit about how 
> principles of peloton interactions could be applied to sperm
aggregations. 
> I've outlined some thoughts below.
>
>
>
> __
>
> DRAFT
>
>
>
> Applications of a peloton model to sperm aggregration dynamics
>
> An analysis of article: Fisher, H., Hoekstra, H. (2010) Competition
drives 
> cooperation among closely related sperm of deer mice. Nature. Vol. 463,
11 
> Feb 801-803
>
> Hugh Trenchard
>
>
> Abstract
>
> The Nature article by Fisher and Hoekstra suggests that a mechanism
exists 
> among the sperm of certain species of mice to identify genetic relatives. 
> The identification mechanism itself is not apparent and, based upon 
> observations of analogous processes in bicycle pelotons, an alternative 
> hypothesis is suggested.  There are similarities between bicycle pelotons 
> and sperm aggregations: they are both competitive dynamical systems, and 
> there are energy savings mechanisms by which agents couple and facilitate 
> self-organized aggregate formations.  A model for the division of a
peloton 
> at critical output levels is shown and suggested as analogous to certain, 
> but not all, sperm aggregations, and a model for the relative energy 
> consumption of coupled and non-coupled aggregates is shown, which
suggests 
> how sub-aggregates may form that are composed of agents within a narrowed 
> fitness range, and also why the strongest individual agents may not
always 
> reach the target objective first.  This suggests that no mechanism is 
> required for the identification of genetic relatives, but that sorting 
> occurs according to a self-organized metabolic process whereby sperm with 
> close fitness levels will aggregate.  Sorting among sperm is hypothesized
to 
> occur at a critical output threshold, and is more likely to occur among 
> promiscuous species than monogamous species because sperm velocity of 
> monogamous species may not be high enough to reach the critical sorting 
> threshold.  Genetically related sperm are more likely to have closer
average 
> fitness levels, and so will naturally sort into groups composed of 
> predominantly related sperm. Thus proposed is an alternative framework by 
> which to analyze the data.
> ___
>
>
>
>
>
> Introduction
> Fisher and Hoekstra (2010) provide evidence that supports the 
> hypothesis that sperm identify related sperm, aggregate and cooperate
with 
> them and, through increased velocity when travelling in aggregations, 
> provide an advantage to genetically related sperm in advancing one of
their 
> kind to impregnate the egg. The authors report a species of mouse whose 
> sperm exhibits "the ability to recognize sperm based on genetic
relatedness 
> and preferentially cooperate with the most closely related sperm." The 
> question was raised: "how do sperm identify their brothers?" (FRIAM,
2010). 
> The question reveals a problem in Fisher's and Hoekstra's analysis, and a 
> clear mechanism for this identification process does not appear to be 
> suggested in their article.
>
> Observations of peloton dynamic