Group Selection

in article [email hidden], John Edser at [email hidden]
wrote on 2/18/04 9:39 PM:

Quoted message said:

JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat:

"A larger group is NOT necessarily naturally selected over a smaller group".

This is definitely true, just as larger individual organisms don't always have higher fitnesses than
smaller individual organisms. Indeed, the only trait that can be universally advantageous (i.e., not
contingent upon environmental conditions) is higher fitness itself.

Guy

<< > "A larger group is NOT necessarily

Quoted message said:

naturally selected over a smaller group". >>

Perhaps, but isn't the fact that the larger group has a larger gene pool to choose from favor it
over a group with a smaller gene pool though that smaller pool has more drift?

Quoted message said:

JE:-
I _was_ making a _valid_ and specific
point re: group selection which I shall
repeat:

"A larger group is NOT necessarily naturally selected over a smaller group".

GH:- This is definitely true, just as larger individual organisms don't always have higher fitnesses
than smaller individual organisms. Indeed, the only trait that can be universally advantageous
(i.e., not contingent upon environmental conditions) is higher fitness itself.

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to why
this is the case.

Respectfully,

John Edser Independent Researcher

PO Box 266 Church Pt NSW 2105 Australia

[email hidden]

Quoted message said:

JE:- "A larger group is NOT necessarily naturally selected over a smaller group". >>

TH:- Perhaps, but isn't the fact that the larger group has a larger gene pool to choose from favor
it over a group with a smaller gene pool though that smaller pool has more drift?

JE:- Because one group is more variable than the other does not mean that one group has been
measured to be fitter than the other. One group may appear potentially more fit but we are only
discussing how actual fitness is measured in this case.

Respectfully,

John Edser Independent Researcher

PO Box 266 Church Pt NSW 2105 Australia

[email hidden]

John Edser said:

Quoted message said:

JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat:

"A larger group is NOT necessarily naturally selected over a smaller group".

GH:- This is definitely true, just as larger individual organisms don't always have higher
fitnesses than smaller individual organisms. Indeed, the only trait that can be universally
advantageous (i.e., not contingent upon environmental conditions) is higher fitness itself.

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to
why this is the case.

isn't the logic rather upfront? Any other trait would be adaptive dependant on the situation,
whereas higher fitness is allways 'good'. Being stronger faster and better could but you at a
disadvantage compared to an organism that is weaker slower and worse if its -somehow- able to be
more fit. Its not much of a statement to say high fitness is allways good, but i think the author
was trying to point out that, why should a large group be selected, there is nothing special about
it per se.

snip

Quoted message said:

Quoted message said:

JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat: "A
larger group is NOT necessarily naturally selected over a smaller group".

Quoted message said:

GH:- This is definitely true, just as larger individual organisms don't always have higher
fitnesses than smaller individual organisms. Indeed, the only trait that can be universally
advantageous (i.e., not contingent upon environmental conditions) is higher fitness itself.

Quoted message said:

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to
why this is the case.

RS:- isn't the logic rather upfront?

JE:- Definitely not.

RS:- Any other trait would be adaptive dependant on the situation, whereas higher fitness is
allways 'good'.

JE:- How exactly do you measure higher fitness in this case?

Quoted message said:

snip<

John Edser Independent Researcher

PO Box 266 Church Pt NSW 2105 Australia

[email hidden]

John Edser said:

Quoted message said:

JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat:

"A larger group is NOT necessarily naturally selected over a smaller group".

GH:- This is definitely true, just as larger individual organisms don't always have higher
fitnesses than smaller individual organisms. Indeed, the only trait that can be universally
advantageous (i.e., not contingent upon environmental conditions) is higher fitness itself.

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to
why this is the case.

You need to see the logic behind a tautology? How do you define fitness? Obviously it's whatever
improves an organism's reproductive success. Which is the same as having an advantage.

--Jeff

--
Ho, ho, ho, hee, hee, hee and a couple of ha, ha, has; That's how we pass the day away, in the merry
old land of Oz.

Quoted message said:

Quoted message said:

JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat: "A
larger group is NOT necessarily naturally selected over a smaller group".

Quoted message said:

GH:- This is definitely true, just as larger individual organisms don't always have higher
fitnesses than smaller individual organisms. Indeed, the only trait that can be universally
advantageous (i.e., not contingent upon environmental conditions) is higher fitness itself.

Quoted message said:

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to
why this is the case.

J:- You need to see the logic behind a tautology?

JE:- No tautology was proposed, AFAICS.

K:- How do you define fitness?

JE:- That is the unanswered question.

L:- Obviously it's whatever improves an organism's reproductive success.

JE:- Reproducing exactly what?

M:- Which is the same as having an advantage.

JE:- Fitness gain causes the advantage. Unless fitness can be exactly defined no advantage can
be measured.

Regards,

John Edser Independent Researcher

PO Box 266 Church Pt NSW 2105 Australia

[email hidden]

in article [email hidden], John Edser at [email hidden]
wrote on 2/23/04 10:08 AM:

Quoted message said:

Quoted message said:

Quoted message said:

JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat: "A
larger group is NOT necessarily naturally selected over a smaller group".

Quoted message said:

GH:- This is definitely true, just as larger individual organisms don't always have higher
fitnesses than smaller individual organisms. Indeed, the only trait that can be universally
advantageous (i.e., not contingent upon environmental conditions) is higher fitness itself.

Quoted message said:

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to
why this is the case.

J:- You need to see the logic behind a tautology?

JE:- No tautology was proposed, AFAICS.

J:- How do you define fitness?

JE:- That is the unanswered question.

J:- Obviously it's whatever improves an organism's reproductive success.

JE:- Reproducing exactly what?

In the context of individual level selection, we are simply talking about old organisms producing
new organisms that are much like themselves (i.e., with some heritability).

Quoted message said:

J:- Which is the same as having an advantage.

JE:- Fitness gain causes the advantage. Unless fitness can be exactly defined no advantage can be
measured.

I is more logical for me to think of the advantageous trait causing a fitness gain, rather than
the other way around. How could you ascribe fitness to an organism without considering all of
its traits?

Regarding the meaning of fitness, I have posted several times on sbe that I view fitness as a useful
concept that has no real existence. Fitness is not an entity or a process. It cannot have an exact
and correct definition in the absence of something real that is being described. It can only have a
vague definition, or an exact definition limited to use in a carefully proscribed context. Fitness
is a concept that has often been defined in exact and concrete ways for the purpose of model
building, but we should not confuse that useful procedure with the notion of fitness as reality.

Cheers,

Guy

in article [email hidden], John Edser at [email hidden]
wrote on 2/20/04 10:31 PM:

Quoted message said:

Quoted message said:

JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat:

"A larger group is NOT necessarily naturally selected over a smaller group".

GH:- This is definitely true, just as larger individual organisms don't always have higher
fitnesses than smaller individual organisms. Indeed, the only trait that can be universally
advantageous (i.e., not contingent upon environmental conditions) is higher fitness itself.

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to
why this is the case.

As another responder noted, higher fitness us universally favored by natural selection
tautologically. Because the relationship between fitness and any other trait (e.g., size) is
necessarily contingent upon the external environment, the universal relationship between fitness and
selective bias cannot exist for any particular trait other than fitness itself.

Guy

John Edser said:

Quoted message said:

Quoted message said:

JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat: "A
larger group is NOT necessarily naturally selected over a smaller group".

Quoted message said:

GH:- This is definitely true, just as larger individual organisms don't always have higher
fitnesses than smaller individual organisms. Indeed, the only trait that can be universally
advantageous (i.e., not contingent upon environmental conditions) is higher fitness itself.

Quoted message said:

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to
why this is the case.

J:- You need to see the logic behind a tautology?

JE:- No tautology was proposed, AFAICS.

J:- How do you define fitness?

JE:- That is the unanswered question.

J:- Obviously it's whatever improves an organism's reproductive success.

JE:- Reproducing exactly what?

Having the most offspring. Isn't that the whole point of evolution? Then again, however you define
an advantage - doesn't that imply that the species is more fit?

Quoted message said:

J:- Which is the same as having an advantage.

JE:- Fitness gain causes the advantage. Unless fitness can be exactly defined no advantage can be
measured.

Now you've stumped me. I thought species competed for ecological niches and that winning a niche was
evidence of both fitness and an evolutionary advantage. Why am I beginning to feel like Alice in
Wonderland?

--Jeff

And why do the threads in this NG not line up?

--
Ho, ho, ho, hee, hee, hee and a couple of ha, ha, has; That's how we pass the day away, in the merry
old land of Oz.

Quoted message said:

Quoted message said:

Quoted message said:

JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat: "A
larger group is NOT necessarily naturally selected over a smaller group".

Quoted message said:

Quoted message said:

GH:- This is definitely true, just as larger individual organisms don't always have higher
fitnesses than smaller individual organisms. Indeed, the

only

Quoted message said:

Quoted message said:

trait that can be universally advantageous (i.e., not contingent upon environmental conditions)
is higher fitness itself.

Quoted message said:

Quoted message said:

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to
why this is the case.

Quoted message said:

J:- You need to see the logic behind a tautology?

Quoted message said:

JE:- No tautology was proposed, AFAICS.

Quoted message said:

J:- How do you define fitness?

Quoted message said:

JE:- That is the unanswered question.

Quoted message said:

J:- Obviously it's whatever improves an organism's reproductive success.

JE:- Reproducing exactly what?

GH;- In the context of individual level selection, we are simply talking about old organisms
producing new organisms that are much like themselves (i.e., with some heritability).

JE:- I think you have to be more specific. I defined reproduced organisms as only _fertile_
reproductions, i.e. I have specifically excluded infertile immatures as valid units of fitness. I
suggest that when Darwin talked about parents raising their offspring, he was talking about the same
thing; _fertile_ forms. Once genes were identified then surely this is just obvious because genes
trapped within a sterile body cannot be selected for or against only using a sterile body.

Quoted message said:

J:- Which is the same as having an advantage.

Quoted message said:

JE:- Fitness gain causes the advantage. Unless fitness can be exactly defined no advantage can be
measured.

GH:- It is more logical for me to think of the advantageous trait causing a fitness gain, rather
than the other way around. How could you ascribe fitness to an organism without considering all of
its traits?

JE:- I can only conclude you have reversed cause and effect reducing evolutionary theory to just a
non testable status in the process.

I agree you have to include all traits. This means each _individual_ trait's fitness must be
_dependent_. What must now be defined is exactly what each trait is dependent on. Remember, we are
trying to provide the logic as to why a larger group is not necessarily fitter than a smaller group.
We have concluded that a trait that expands a population when selected at the organism group level
(but not at the individual level) does not necessarily provide a increase in fitness as measured at
the _group_ level of selection. A logic must be supplied for this conclusion otherwise it is just
pointless hand waving.

GH:- Regarding the meaning of fitness, I have posted several times on sbe that I view fitness as a
useful concept that has no real existence.

JE:- If this was the case then Darwinian evolution by natural selection was never a testable process
and no valid scientific view of evolution exists.

GH:- Fitness is not an entity or a process.

JE:- Fitness is just an objective count of _something_ allowing the prediction that some biological
entity will be selected for/against.

GH;- It cannot have an exact and correct definition in the absence of something real that is being
described.

JE:- Yes, fitness must be able to be counted in reality, i.e. within _nature_ e.g. not just within a
computer simulation.

GH:- It can only have a vague definition, or an exact definition limited to use in a carefully
proscribed context.

JE:- No. Only _contesting_ and _exact_ definitions of fitness allow scientific research into
evolution. Different propositions of fitness must be eliminated by the Popperian process of
refutation until just one exists on the table.

GH:- Fitness is a concept that has often been defined in exact and concrete ways for the
purpose of model building, but we should not confuse that useful procedure with the notion of
fitness as reality.

JE:- I agree that any over simplified model of fitness cannot validly contest and win against any
theory that provided n objective measure of fitness in-the-first-place.

Since you have already posted that "fitness as a useful concept that has no real existence" where
this statement stands in stark _contradiction_ to what you subsequently wrote: "but we should not
confuse that useful procedure with the notion of fitness as reality" then sbe reader's can have no
idea what you mean by "fitness". How can such a contradictory notion of fitness allow you to validly
conclude that a larger group is not necessarily fitter than a smaller group?

Regards,

John Edser Independent Researcher

PO Box 266 Church Pt NSW 2105 Australia

[email hidden]

Quoted message said:

Quoted message said:

JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat: "A
larger group is NOT necessarily naturally selected over a smaller group".

Quoted message said:

GH:- This is definitely true, just as larger individual organisms don't always have higher
fitnesses than smaller individual organisms. Indeed, the only trait that can be universally
advantageous (i.e., not contingent upon environmental conditions) is higher fitness itself.

Quoted message said:

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to
why this is the case.

GH:- As another responder noted, higher fitness us universally favored by natural selection
tautologically.

JE:- Such a view has little merit unless fitness can be objectively measured.

GH:- Because the relationship between fitness and any other trait (e.g., size) is necessarily
contingent upon the external environment, the universal relationship between fitness and selective
bias cannot exist for any particular trait other than fitness itself.

JE:- Does what you wrote mean that each trait's fitness is dependent? If so, what is each trait's
fitness dependent on?

Respectfully,

John Edser Independent Researcher

PO Box 266 Church Pt NSW 2105 Australia

[email hidden]

Quoted message said:

Quoted message said:

Quoted message said:

JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat: "A
larger group is NOT necessarily naturally selected over a smaller group".

Quoted message said:

Quoted message said:

GH:- This is definitely true, just as larger individual organisms don't always have higher
fitnesses than smaller individual organisms. Indeed, the only trait that can be universally
advantageous (i.e., not contingent upon environmental conditions) is higher fitness itself.

Quoted message said:

Quoted message said:

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to
why this is the case.

Quoted message said:

J:- You need to see the logic behind a tautology?

Quoted message said:

JE:- No tautology was proposed, AFAICS.

Quoted message said:

J:- How do you define fitness?

Quoted message said:

JE:- That is the unanswered question.

Quoted message said:

J:- Obviously it's whatever improves an organism's reproductive success.

Quoted message said:

JE:- Reproducing exactly what?

J:- Having the most offspring. Isn't that the whole point of evolution? Then again, however you
define an advantage - doesn't that imply that the species is more fit?

JE:- If these offspring are sterile so that their genes cannot be passed on until they become
fertile, then such forms can only have zero fitness until they become fertile.

Species are just an arbitrary grouping of Darwinian fertile forms that exist in separate evolving
populations. Once you start talking about the fitness of a species you are making the classical
group selective argument. Such a grouped fitness is only the addition of the Darwinian fitness of
each separately selected fertile form within it. In this instance, a species as one unit of
selection can only be group selected after selection at the fertile form level that exists within it
has been completed. This means that group selection cannot contradict selection at the individual
level since when it does so the fitness of both levels of selection must be reduced.

Quoted message said:

J:- Which is the same as having an advantage.

Quoted message said:

JE:- Fitness gain causes the advantage. Unless fitness can be exactly defined no advantage can be
measured.

K:- Now you've stumped me.

JE:- If a fitness gain does not cause the advantage then no way exists to measure any supposed
advantage so the supposed advantage is just subjective hand waving.

L:- I thought species competed for ecological niches and that winning a niche was evidence of both
fitness and an evolutionary advantage.

JE: Competition is _firstly_ happening _within_ a species grouping and not between species groups.

M:- Why am I beginning to feel like Alice in Wonderland?

JE:- Because you appear to be making a self contradictory argument. You have to decide if you think
group selection:

1) Is happening at all.
2) Provide a fitness measure for group selection.
3) Decide if the Darwinian fertile organism level of selection dominates the group level or
vice versa.

Regards,

John Edser Independent Researcher

PO Box 266 Church Pt NSW 2105 Australia

[email hidden]

in article [email hidden], John Edser at [email hidden]
wrote on 2/25/04 9:04 AM:

Quoted message said:

Quoted message said:

Quoted message said:

> JE:- I _was_ making a _valid_ and specific point re: group selection which I shall repeat: "A
> larger group is NOT necessarily naturally selected over a smaller group".

Quoted message said:

Quoted message said:

GH:- This is definitely true, just as larger individual organisms don't always have higher
fitnesses than smaller individual organisms. Indeed, the

only

Quoted message said:

Quoted message said:

trait that can be universally advantageous (i.e., not contingent upon environmental conditions)
is higher fitness itself.

Quoted message said:

Quoted message said:

JE:- I think it would be of enormous benefit to sbe readers if you could outline the logic as to
why this is the case.

Quoted message said:

J:- You need to see the logic behind a tautology?

Quoted message said:

JE:- No tautology was proposed, AFAICS.

Quoted message said:

J:- How do you define fitness?

Quoted message said:

JE:- That is the unanswered question.

Quoted message said:

J:- Obviously it's whatever improves an organism's reproductive success.

JE:- Reproducing exactly what?

GH;- In the context of individual level selection, we are simply talking about old organisms
producing new organisms that are much like themselves (i.e., with some heritability).

JE:- I think you have to be more specific.

GH:- You asked what it was that reproduces and I answered with complete specificity in the context
of individual level selection.

Quoted message said:

I defined reproduced organisms as only _fertile_ reproductions, i.e. I have specifically excluded
infertile immatures as valid units of fitness. I suggest that when Darwin talked about parents
raising their offspring, he was talking about the same thing; _fertile_ forms. Once genes were
identified then surely this is just obvious because genes trapped within a sterile body cannot be
selected for or against only using a sterile body.

GH:- Are you concerned that I may have implied a role for the reproduction of unfertile forms. That
would be a bizarre source of confusion that must come from an agenda that had nothing to do with my
answer above.

Quoted message said:

Quoted message said:

J:- Which is the same as having an advantage.

Quoted message said:

JE:- Fitness gain causes the advantage. Unless fitness can be exactly defined no advantage can be
measured.

GH:- It is more logical for me to think of the advantageous trait causing a fitness gain, rather
than the other way around. How could you ascribe fitness to an organism without considering all of
its traits?

JE:- I can only conclude you have reversed cause and effect reducing evolutionary theory to just a
non testable status in the process.

I agree you have to include all traits. This means each _individual_ trait's fitness must be
_dependent_.

GH:- Traits can't really have fitness because they don't actually exist, except as abstractions.
Aside from this minor point, I agree that the fitness of an individual involves the integrated
affects of all its traits.

Quoted message said:

JE:- What must now be defined is exactly what each trait is dependent on.

GH:- I presume you mean the fitness of each trait, which is a slippery concept for me, given the
abstract nature of traits. Still, I will go along with your logic for now. I don't see, however, why
this is a necessary next step.

Quoted message said:

JE:- Remember, we are trying to provide the logic as to why a larger group is not necessarily
fitter than a smaller group.

GH:- OK.

Quoted message said:

JE:- We have concluded that a trait that expands a population when selected at the organism group
level (but not at the individual level) does not necessarily provide a increase in fitness as
measured at the _group_ level of selection.

GH:- This is coming out of the blue to me. I am certainly not part of your "we" that ever arrived at
such a conclusion. I argue that a response to selection at any level generically tends to increase
fitness at that level in a constant environment.

[snip]

Quoted message said:

GH:- Regarding the meaning of fitness, I have posted several times on sbe that I view fitness as a
useful concept that has no real existence.

JE:- If this was the case then Darwinian evolution by natural selection was never a testable
process and no valid scientific view of evolution exists.

GH:- That may well be the case in your conceptual framework for science, which I do not share.

Quoted message said:

GH:- Fitness is not an entity or a process.

JE:- Fitness is just an objective count of _something_ allowing the prediction that some
biological entity will be selected for/against.

GH:- So then, you agree with me that fitness does not have any natural existence.

Quoted message said:

GH;- It cannot have an exact and correct definition in the absence of something real that is being
described.

JE:- Yes, fitness must be able to be counted in reality, i.e. within _nature_ e.g. not just within
a computer simulation.

GH:- I agree that operational definitions of fitness surely ought to be quantifiable.

Quoted message said:

GH:- It can only have a vague definition, or an exact definition limited to use in a carefully
proscribed context.

JE:- No. Only _contesting_ and _exact_ definitions of fitness allow scientific research into
evolution. Different propositions of fitness must be eliminated by the Popperian process of
refutation until just one exists on the table.

GH:- I disagree. This is a completely worthless exercise for something like fitness, which has no
natural existence.

Quoted message said:

GH:- Fitness is a concept that has often been defined in exact and concrete ways for the purpose
of model building, but we should not confuse that useful procedure with the notion of fitness as
reality.

JE:- I agree that any over simplified model of fitness cannot validly contest and win against any
theory that provided n objective measure of fitness in-the-first-place.

Since you have already posted that "fitness as a useful concept that has no real existence" where
this statement stands in stark _contradiction_ to what you subsequently wrote: "but we should not
confuse that useful procedure with the notion of fitness as reality" then sbe reader's can have no
idea what you mean by "fitness". How can such a contradictory notion of fitness allow you to
validly conclude that a larger group is not necessarily fitter than a smaller group?

What contradiction? Those statements seem unambiguously consistent to me. To review: fitness does
not really exist, but it is a heuristically useful concept. Fitness should, and usually is,
operationally defined in concrete terms for the purpose of modeling. The diversity of selection
models has appropriately resulted in a plethora of concrete, operational, measurable definitions;
but none of these concrete definitions should blind us to the fact that fitness is merely a vague
conceptual tool in the general theory.

Cheers,

Guy