john edser

JE:-
An exact, finite, measure of fitness DOES exist
which is not just a guess! Further more it can
be tested to refutation, i.e. it does meet a
minimal Popperian requirement for the sciences.
I have termed it: Absolute Darwinian fitness.
This fitness was always implicit within
Darwin's writings.

_____________________________________________
Absolute Darwinian Fitness (ADF):

The total number of fertile forms reproduced
into one population by each parent.

Notes:

1) At the gene level this fitness is
entirely gene fitness epistatic, i.e. it
is measured as a _non_ additive fitness.
This being the case it is just deleted
within gene centric Neo Darwinism using
Fisher's dictum: only non epistatic traits
are heritable and thus selectable. The
refutation of Haldane's basis for the so
called "Haldane's Dilemma" refutes Fisher's
proposition that only non epistatic fitnesses
are heritable. The human genome is too small
to restrict heritability to just additive gene
information.

2) ADF is not infinite it is finite.

3) ADF cannot be selected to be lowered so it
constitutes a valid fitness maximand for the
science of biology.

4) This maximand can be tested to refutation.

5) I have outlined an experiment that can test
ADF to refutation. It also allows so called
"evolution" via random processes such as genetic
drift to be tested to non verification (which
is not definitive).
_____________________________________________

In BIOLOGY fitness remains finite and objective
so that it can be exactly measured. It can be shown
that Darwinian fitness is just the default
comparison of the ADF of each selectee within
one population where ADF is assumed to
have a high heritable component. PS's infinite
view of fitness remains entirely gene centric and
not at all organism centric forcing fitness to
become just an infinite non testable model. A
model is not a theory it is just a simplification
of an existing theory. The only way you can attempt
to measure an infinite model fitness is by just
a guess. A guess cannot VALIDLY compete against
any exact measure, especially a measure that
allows a point of refutation! Infinite
models of gene centric fitnesses are
utterly misused when they attempt to replace
the theory they were simplified from.


Regards,

John Edser
Independent Researcher

PO Box 266
Church Pt
NSW 2105
Australia

edser@tpg.com.au

phillip smith

in article cnu0s1$2t5c$1@darwin.ediacara.org, John Edser at edser@tpg.com.au


How can we know this. Presumably we can only know this when the individual
is dead. As they may other wise have more offspring in the future. Also do
you count the fertile offspring if they all fail to reproduce even if though
are fertile. They may be fertile but have a mutated mate recognition system
or perhaps they breed but the next generation dies.
Mutations like grandchild less

http://www.ucalgary.ca/UofC/eduweb/virtualembryo/mago.html

Would up set your case. If you parents produced offspring with the
grandchildless phenotype would be fertile but would have no grandchildren

Are you sure of this? Are you saying that all organisms are producing as
many offspring as they can regardless of consequence. Or are you suggesting
that every individual is producing the "just right" number of offspring.

I don't think you have shown this.


I should perhaps clear up a misconception. I am not in favour of a gene
centric view of evolution. Quite the opposite in fact. At the moment I am
more interested in whole genomes than genes. I am not a fan of fitness
either. What I am trying to point out is that fitness and genes are tied
together, with the species concept, these three wobbly legs prop up the
neo-darminism stool. If any of these can legs can be nocked out the whole
thing come crashing down. It is our duty to keep trying to do this.


I'm not sure what you mean by infinite model? Is you finite model giving no probabilistic measure of fitness?

ekurtz

How can we know this. Presumably we can only know this when the individual

Looking at this issue from the point of view of an outsider, I get the
feeling that "fitness", which is essentially a statement about probability
of survival (of something) over time, has been reified into an attribute of
an organism, similar to objective characteristics such as weight and color.
As a result, we are eternally immersed in pointless theological disputes
about its meaning and relevance.
Consider the case of a ***ual species into which a parthenogenic female is
introduced by mutation. Assuming that she and her immediate offspring
survive, and that the population size is constant, her offspring will
effectively displace the ***ual type in a few dozen generations. But
ultimately the population will likely suc***b to disease as a result of lack
of genetic diversity. So what is the "fitness" of the mutation that caused
the transformation? A meaningless question, in my view. The only thing that
matters is the probability at any time after the mutation is introduced that
its populational frequency has a given value. Without the introduction of
time and probability, no understanding of fitness is possible.
When we say that a novel variation confers "fitness", we are merely guessing
about its effect on the population in the near future.

anon.

One thing that is stressed to students (and then, no doubt, subsequently
forgotten) is that fitness is defined with respect to a particular
environment. Change the environment, change the fitness. In that
sense, it is a property of an individual: in environment X, individual Y
will have fitness Z.

Of course, from an instrumentalist perspective, you're right that it's
the frequency in a population that is ultimately important, but fitness
is a major determinant of that. Hence its importance.

Bob

--
Bob O'Hara
Department of Mathematics and Statistics
P.O. Box 68 (Gustaf Hällströmin katu 2b)
FIN-00014 University of Helsinki
Finland

Telephone: +358-9-191 51479
Mobile: +358 50 599 0540
Fax: +358-9-191 51400
WWW: http://www.RNI.Helsinki.FI/~boh/
Journal of Negative Results - EEB: http://www.jnr-eeb.org

william morse

This has been much discussed, but I will jump in again. I can agree that
fitness is a statement about probability of survival, but that
probability _is determined by_ objective attributes of an organism. To
grossly oversimplify a complex subject, in a number of niches organisms
that can fly will survive better than those that can't, unless they
happen to wind up on an island with no significant predators. Organisms
with long pointed snouts, strong claws, and no teeth will be better at
eating ants than those with different characteristics. Organisms that can
see will survive better than those that can't, unless they happen to live
in caves.

Now probability is definitely important, as witness the significance of
drift in evolution. And fitness is always relative to the environment,
which changes with time. So I also agree that any statement about the
"fitness" of a novel variation can only be a probabilistic assessment.
But let us not throw out the baby with the bathwater. We can in fact make
assessments about probable futures (e.g. via Markov chains), so if we can
come up with a realistic estimate of the added fitness of a given
variation (the devil as usual is in the details), we can make meaningful
predictions.

Yours,

Bill Morse

peter f

(Talking about "importance"

What greater "importance" of modern
Darwinian natural philosophy (not the same as molecular
genetics) is there, other than the extent to which it can
provide a complementary ****ytical approach to
getting to know ourselves!?

Given roughly repeating patterns in the phylogeny of fauna,
the possibility of recognizing "generic types" of lifetime
challenges (come naturally selective situations) can be
put to use [in the manner of "Opportunity type" selective pressures
+ SHITS (+CURSES) => AEVASIVE] to an effect similar to
holding up a mirror in front of ourselves.

However, [for precisely this set of EPTly abbreviated reasons - inserted above] people automatically
prefer less disconcerting theoretical sights.

P


--
Partly inspired by MAD (cold war shaming acronym), I arrived at EPT
[e.g: eclectically Explanatory perversely Pert
philosophical Terminology] and by concEPTual lenses/tools saw/grasped how
and why AEVASIVE preoccupations (personalities) normally preclude making
in dEPTh sense (of themselves).
In the acronym for Ambiadvantageously Evolved 'V-word' Actention
Selection (System) Involving Various Endorphins, AS(S) stand for how we
think/emote/behave based on our individual repertoire of competing {by
mutual inhibition) whilst cheered and booed {by current and past
environmental influences) "actention modules", & AE refer to the didactic
division of the Evolutionary Pressure Totality into relevant dialectic
lifetime juxtapositions of:
1. Opportunity
2. Adversity - here especially SHITS [Synaptic Hibernation Imploring
{naturally selective AND 'motivating' of selective unconsciousness)
Traumatic {also tardily so) Situations] normally repercussively retained as
CURSES type memory aka "Pain" (Janov)

an588

"EKurtz" (NoJunk@ForgetIt.com) writes:

Even if the parthenogenetic individuals average only 1.5
fertile offspring each, they will tend to take over the whole
population. The ***ual ones could be declining while
averaging 1.8 offspring each, while the parthenogenetic ones
grow exponentially at 1.5 offspring each. So number of
fertile offspring is not a very useful definition of "fitness".

I hypothesize that ***ual species alive today have characteristics
that make it difficult for parthenogenesis to occur, as a result
of billions of years of evolution in which species after species
was taken over by parthenogenesis and then suc***bed to
changes in the environment better handled by ***ual species.

It would not be an elaborate mechanism to prevent parthenogenesis;
that could easily be mutated away. It would have to be a more
subtle near-inability to mutate to parthenogenesis -- for example,
a chemical in sperm without which eggs cannot begin dividing,
not simply because the eggs respond to a "signal" -- the instruction
to wait for a signal could mutate away -- but because the chemical
is absolutely essential to cell division and the genome does
not specify the manufacture of this chemical in eggs.
Or something like that. Something that makes the sudden
appearance of parthenogenesis almost as unlikely as the
appearance of eyes in sightless species.

Sometimes an inability is an asset, as Pinker
explains in "How the Mind Works."
--
Cathy

ekurtz99

Exactly. The effect of the displacement of one type by the other will be
compounded as the number of males declines, since males will presumably
not be able to distinguish ***ual from non-***ual females, and thus will
mate unproductively with the non-***ual type more and more as the
proportion of the ***ual type dwindles.

Unless of course the mutation that causes parthenogenesis simultaneously
causes the affected females to reject males. This seems unlikely. In one
case the females actually mate with each other!

animaldiversity.ummz.umich.edu/accounts/cnemidophorus/c._sonorae$narrative.html

"Cnemidophorus sonorae [the sonoran spotted whiptail lizard] is a
uni***ual, all-female species that breeds by parthenogenesis (Goldberg
et al. 1997, Routman and Hulse 1984, Porter et al. 1994). Ovulation is
often stimulated by "pseudocourtship" among the females; the
unfertilized eggs develop into hatchlings that are genetically identical to their mothers."

I would suggest that the correct term to describe it is "useless".

The "number of fertile offspring" also fails in the case of a species
that contains one type of female that produces a large number of weak
but fertile offspring and another than produces a small number of strong
and fertile offspring. A sufficiently large proportion of the strong
type could survive and ultimately displace the "fitter" weak type.

It fails also in the case where the "fitter" type produces, say, 8
offspring every year and the "less fit" type produces 6 offpring every 6
months.

The success or failure of a genetic alteration, such as a mutation, is a
consequence, not of a unary measure of fitness, but of the entire
situation of the organism in which the alteration takes place. This
includes not only the effect of the environment on the organism, but the
organism's effect on its environment (which is usually neglected in
discussions of fitness). It is also a function of time, as the example
of parthenogenesis shows, since initally adaptive changes can later become fatally maladaptive.


Indeed. ***uality survives by default. Could this be the explanation of
all the extinctions we see in the fossil record?

One of Pinker's assets is the confidence to produce a work of that name
when he in fact has no idea "How the Mind Works", and neither does anyone else.

tim tyler

Yes - all other things being equal.

However a***ual reproduction affects other things besides how fast the
population can reproduce. In particular it affects the success rates of
parasites adapted to one individual in afflicting that individual's
friends and relatives.

....so in practice other things are rarely equal.
--
__________
|im |yler http://timtyler.org/ tim@tt1lock.org Remove lock to reply.

william morse

But what if (as is normally the case for most organisms) the average number
of offspring (before predation and disease) is on the order of hundreds to
thousands? In this case the parthenogenetic individuals have very little
advantage in terms of having more offspring - they invest less energy per
offspring but that investment is not particularly large - while their
offspring suffer higher rates of predation and especially disease. Under
these cir***stances (which again are the norm for most organisms)
parthenogenesis does not have any advantage.


Yours,

Bill Morse