Category Archives: fitness

Working Hard on Special Biological Relativity

I’ve been working hard on Special Biological Relativity and it is taking up most of my blogging energy.  However, I do have some fun results:

Define Biological Energy as the ability to do work, the ability to change the environment.  Then Fitness can be related to Energy because the higher the fitness the greater the ability to change the environment.

E ∝ f

If we consider an organism that lives in a place with infinite resources – a Garden of Eden – and also replicates at the speed of the chemical reaction of replication – there is no maturation process, it immediately starts to replicated as soon as it is created – then it’s life is identical to it’s replication process.  Define d to be the speed of the chemical process of replication.  Then the ability of this organism to change the environment is given by it’s fitness, the rate it replicates at and it’s life:

E = fd2

Or something.

Posted in biology, evolution, fitness, philosophy, science, Special Relativity. Tagged with , , , , , .

Special Relativistic Fitness, Preliminary Thought Experiment

Imagine two different tribes of biologists.  The first tribe is comprised of very fast people.  They survived for thousands of years by studying biology and being faster than their competitors.  The second tribe is comprised of very strong people.  They survived for thousands of years by studying biology and being stronger than their competitors.  After all this time, the first tribe is filled with very fast biologists and the second tribe is filled with very strong biologists.

Now imagine that two biologists, one from each tribe, are evaluating the fitness of two organisms.  One of the organisms is fast, the other is of average speed.  Other than the difference in speed, they are identical.  The strong biologist recognizes that one is faster than the other, but does not find this to be significant and assigns the two organisms equal fitness.  The fast biologist recognizes that one is faster and assigns it a slightly higher fitness because of its speed advantage.

Is the difference in fitness evaluations a matter of scientific opinion?  If it were an opinion that the fast organism was fitter, this would be a scientific opinion based upon environmental and competitive factors.  Given different competition and environment, the evaluation would have come out differently.  However, the fast biologist and her entire tribe have survived by being faster than their competition.  Her evaluation is not only scientifically based but also partly based upon her evolutionary heritage and Weltanschung that is finely attuned to how speed is beneficial.  It is these factors, unique to people of this tribe, that give more weight to speed as evolutionarily significant and makes it more than just a case of scientific disagreement.

Is the fast biologist unfairly biased? If we consider the perspective of the strong biologist, we can see that the strong biologist has no greater claim to her appraisal of an organism’s fitness: strength is just as arbitrary a trait as speed and this thought experiment could have equally been set up with two organisms that only differed in strength.  Hence the fast biologist could equally claim the strong biologist is unfairly biased toward strength and away from speed.  Generalizing, we can say that no one perspective, be it speed, strength, sight, etc., or any combination of traits, is privileged.  Hence their is no unfair bias because every scientific perspective based upon evolutionary heritage and an associated Weltanschung is as legitimate as any other.

Lastly, consider that every biologist will recognize the same amount of phenotypic difference between two organisms;  difference in phenotype does not permit variation in interpretation.  Therefore any difference in fitness evaluation is not due to a perceived physical difference by the biologists in the organisms studied.

Therefore this thought experiment implies that our determinations of fitness are not independent of the evolutionary history of the biologist(s) making those determinations.   Insofar as we cannot escape our own biology and how it shapes our views, it will determine the fitness value we assign to organisms, if only to a small extent.

Consequences:

In one sense everything on Earth has been evolving for the exact same amount of time, since the dawn of life, and hence no organism alive is any more evolved than any other.

However, from the perspective of the fast biologists, the fast organism is more evolved.  Insofar as the fast biologists believe that life is evolving towards moving faster, the organism that moves faster has adapted before the other organisms.  So, in the special circumstance of a population perceiving evolution to move regularly towards a trait, an organism with that trait can be considered more evolved.

—– the analogs —–
evolutionary significant events are specific adaptations :: physically significant events are light flashes
regular evolutionary change is a population with trait selection :: regular motion is a non-accelerating inertial frame
difference in phenotype does not permit variation in interpretation, regardless of observer :: failure of addition of velocities of light, regardless of observer.
upper limit to adaptation- by definition, no jumps :: speed of light in vacuum defined as c

Posted in biology, evolution, fitness, philosophy, Special Relativity. Tagged with , , , , , .

Deriving Natural Selection = Fitness × Acceleration

As you can see from my previous post, I now have postulated a direct relation between Natural Selection and Fitness (N.S.=F.×A.).  This relation follows from the theory.

The short short short version of the theory is this general postulate: one organism’s traits are another’s environment and vice versa.  Hence all competition can be viewed as environmental phenomena.  This gives Natural Selection as a result of Fitness and an environmental factor, which I refer to as Acceleration.

If you want to see the paper as it stands now, you can access it here or below.[6in/120mm ebook formatted]

Posted in biology, evolution, fitness, General Relativity, philosophy, physics, Relativity, science. Tagged with , , , , , , .

Natural Selection = Fitness × Acceleration

Natural Selection is the force that changes species.

Fitness is the resistance to change in the rate of change of the species.

Acceleration is change in the rate of change of the species.

Natural Selection = Fitness × Acceleration

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Rewrite of Evolution

New theory of evolution!  Hooray!

Patched a bunch of things together to make a nice story.  Fixed the little issue about fitness being circular.  Expanded natural selection to apply more generally.  Causal structure.  Epistemological foundations.  ooOoOO0Ooooooo.

And it’s good fun.  I swear.  Epistemology, history of physics, evolution… makes me happy.  You should really read it.

Download here. [pdf, 304kb]

Posted in biology, epistemology, evolution, fitness, General Relativity, measurement, philosophy, physics, Relativity, science. Tagged with , , , , , , , .

On Block and Kitcher on Fodor

Ned Block and Philip Kitcher have posted a review of Fodor/Piatelli-Palmarini’s “What Darwin Got Wrong” (via Leiter).

It is a well executed, though flawed, counter to Fodor’s arguments.  First they give a nice rundown of the underdetermination issue I posted about here.

Then they discuss the “intensional fallacy”.  They argue that the crux of F & P’s argument can be seen as trying to split up the causal efficacious trait and the selected-for trait.  This means that F & P believe that there is no way to connect the evolutionary reason – the trait that increased an organism’s fitness – with our explanation of the trait that was selected-for.  Block & Kitcher argue that it is trivial to match the two up because

selection-for is a causal notion, and, since causation is extensional, so is selection-for.

Insofar as we believe that our explanation of the selected-for trait is extensional, i.e. truth-preserving when switching between different names of the same thing, we can say that we do pick out the causally efficacious trait.

Unfortunately Block and Kitcher sacrificed our normal concept of explanation to make this counter-argument.  They note that explanations are never normally extensional, but that we are making an exception in this case.  This is ok to do because

we thinking beings can give (intensional) explanations in terms of [one trait] rather than the other properties. In giving the explanation, we (thinking beings) describe the property in our preferred way.

I do not understand what is going on here.  Basically it looks as if “preferred way” is just a fancy way to say “own words”, but describing something in our own words doesn’t make it right.  Nor is it a reason to change what should count as an explanation.

Unless Block and Kitcher are prepared to give further justification as to why we should disregard our normal understanding of explanation, it looks as if their solution to Fodor’s argument is ad hoc.  They are using explanation* — which is a special kind of explanation that can be extensional — but they have not given a reason why explanation* should be preferred over of regular explanation (outside of causing Fodor trouble).  Without this reason, the use of explanation* is ad hoc, and hence the argument fails because it turns on an ad hoc premise: the assumption that explanation* can be substituted for explanation.

However, I did say above that Block and Kitcher’s argument is well executed:  My argument against using an ad hoc term-term* distinction is obscure compared to their argument and so, for the vast majority of people, it will appear that their argument is effective.  Overall this is a good thing: less nonsense needs to surround evolution (though I’ll be a little sad to see it go: I’m #1 in a Google search for “fodor what darwin got wrong“).

[EDIT:  I’ve put up a new analysis (24 March 2010) of Fodor’s argument here: Hypotheses Natura Non Fingo.  It also includes a review of the responses of Block, Kitcher and Sober ]

For my take on what Fodor got wrong, see my post What Fodor Got Wrong, and the follow up Dismantling Fodor’s Argument (also linked above in reference to underdetermination).  I’ll post something soon specifically addressing the intensionality issue:  Fodor’s Intensional Criticism of Evolution.

Posted in argumentation, biology, evolution, fitness, news, philosophy, science. Tagged with , , , , , .

Sexual Reproduction, The Case for, Round 2

Let us assume that there are different kinds of adaptations.  Specifically, some are better than others in the long run:  some adaptations will only make a difference in an organism’s ability to reproduce viable offspring over a short period of time, whereas others will be beneficial for many generations.

In asexual reproduction there is no mechanism for distinguishing between a short term beneficial adaptation and a long term beneficial adaptation.  This subjects long term beneficial adaptations to being potentially overshadowed by short term beneficial adaptations and genetic drift:  if a short-term genetic change  sweeps through a population, some adaptations can be wiped out.  This sort of (selected for or not selected for) genetic drift would be tempered if it were forced to go across the different biologies of the two sexes.

With sexual selection there is a mechanism for selecting long term beneficial adaptations over short term ones.  Long term beneficial adaptations will have to be good for both sexes:  if an adaptation is beneficial to both the male and female – individuals with significantly different biologies – then it is more likely to be  good for the entire species.  Short term beneficial adaptations may only be good for particular individuals or one sex, depending on the mutation.  This makes it less likely for short term, provincial adaptations (or drift) to last because they won’t be as effective across different the different biological make-up of the two sexes.

Therefore by distributing mutations across two different sexes – two similar but different biologies – long term beneficial adaptations can be selected for.

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Sexual Reproduction

Say you are a single celled organism.  To reproduce you have to double your size and then you need to split yourself in half.  Repeat indefinitely.

Now say you are a single celled organism that has the option to reproduce sexually.  To reproduce you need to increase yourself to 3/2 your original size and find a similar mate.  Then you both contribute 1/2 to the new organism and repeat indefinitely.

Asexual reproduction requires you to double in size; sexual reproduction requires only a 3/2 increase.  Therefore the turn-around time for sexual reproduction is inherently shorter than for asexual reproduction (assuming there are viable mates readily available).

Is there a selective benefit to a shorter turn around time for reproduction?  If the species must constantly be adapting to a changing environment (that would be everyone), then having a higher rate at which new mutations (and thence adaptations) are introduced into the population is critical.

Secondly, given that there is enough food but it takes time to collect, I count more offspring for sexual reproduction:

Sexual Replication vs. Asexual Splitting

In sexual reproduction, there is an additional child from the first generation of children (as compared to asexual splitting) created in the same amount of time: At the +50% mark #1 & #2 mate to create #5, and #3 & #4 mate to create #6.  Then, at the 100% mark (or plus an additional 50%) #1 & #2 mate to create #7, #3 & #4 mate to create #8, and, at the same time, the initial children #5 & #6 mate to create #9.  #9 is also one generation ahead of the offspring of asexual replication.

Now, to be honest, I’m confused.  I don’t think that anything above is particularly complicated.  However, Wikipedia does not note this as a benefit of sexual reproduction.  It actually says that asexual reproduction is much faster.  This makes me think that I must have made a mistake or else someone would have added it.

The going theory appears to be that since every organism in an asexually reproducing species can give off children, then there is twice the potential for offspring.  This completely ignores any struggle that an organism might have that would prevent it from reproducing, or that work can be split with a mate making it easier to reproduce.

My main assumptions are, among others, that there already is a significant population of organisms, the organisms are not too fussy about their mates (no significant waste of energy searching for a mate),  energy / work is being split with the mate, and that the limiting factor has to do with gathering food.  I can’t see how, if these (reasonable?) assumptions hold, sexual reproduction isn’t the dominant, winning strategy.

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Dismantling Fodor’s Argument

Fodor argued that the theory of evolution is not a legitimate theory of science because it is either vacuously true or wrong.  He accused Darwin of committing the intentional fallacy. (synopsis here)

Insofar as he made no logical mistakes in his reasoning, we need a different strategy to defend the theory of evolution.  In this post I will argue that his argument is an instance of gerneral underdetermination, and hence not a problem of evolution but of philosophy of science.

Underdetermination means that we can’t specifically identify the exact cause of scientific phenomena.  For example, given some phenomenon, say darkness during the day, there can be many possible explanations: an eclipse, an exploding volcano shooting ash into the air, the sun has gone out, the electric company has blocked the sun to make more money, it was the work of Claw Vipers, etc.  The exact cause of the darkness is underdetermined; sure we can research the problem and eliminate some of the possible explanations, but because of our limitations we will never be able to check everything.  So the cause of the darkness can be said to be underdetermined, i.e. there is just not enough determining evidence.

Fodor argues that the theory of evolution is vacuous becuase given any trait we identify as benficial to the fitness of the organism is arbitrarily selected.  Since there are too many factors to identify within an ecosystem or organism acting within that ecosystem, any hypothesis we propose about the fitness of that organism in that ecosystem will be trivially compatible with evolution.

For example assume there is an argument that having a certain trait, say longer legs, increases a zebra’s fitness.   We can recognize that this argument could be unfounded because it might not be the longer legs but something else that increases the zebra’s fitness.  It just happened that increased leg length was a harmless side affect of this truly beneficial trait.  Either way, if it is the longer legs or some other unidentified trait, evolution is always compatible with our theories, and so it is trivially vacuously true.

In short I would say that he is arguing the cause of natural selection is underdetermined.  The task is to identify whether this is a unique case of underdetermination or an instance of general underdetermination.  I will now show that this sort of underdetermination can exist in physics*:

Imagine we are doing physics and we want to know which of two metal ingots is the more massive.  We pull out our scale, place each object on one of the trays and wait for the scale to indicate which is the more massive.

Why does the scale tip in the direction of object A?  We could argue that object A has a trait, it is composed of iron, and that trait makes it more massive than some other object.  However, maybe object B is connected to a helium balloon.  Maybe there is a gravitational anomaly in the location where we are doing our experiment.  Maybe the iron is magnetized and there is another ingot with the opposite polarity under the table.  Maybe a God is tampering with our experiment with a noodly appendage.  Feel free to make up as many of these as you want.  There any number of reasons why one object could tip the scale in its favor, and being more massive is among them, though selecting this as the reason is arbitrary.

(One of the things that is wrong here is that we don’t expect General Relativity to predict which objects are more massive.  The mass of an object is the result of the history of its creation and ‘life’ up till the point we measure it.  We do expect Relativity to suggest methods for testing such claims, which it does.  Likewise Evolution should not be expected to predict which organism is fitter, but to suggest methods for testing fitness.)

If I now recast Fodor’s criticism into physical terms, in reference to the above thought experiment, this is the result: The theory of General Relativity (gravity) is vacuous because any given trait we identify as increasing the mass of an object is arbitrarily selected.  Since there are too many factors to identify within a physical system, any hypothesis we propose about mass of the object in that physical system will be trivially compatible with General Relativity.

Therefore physics suffers from the same kind of underdetermination that Fodor accused of evolution.  Anyone who persists in disbelieving evolution on these grounds should also deny General Relativity.  Of course this is excessive: since the underdetermination criticism goes to the heart of our scientific theories in general, it is a problem of philosophy of science and not a problem of biology or physics specifically.  Insofar as underdetermination remains an issue within the philosophy of science we still have to take it into consideration, but this should not be seen as a reason to think our current scientific theories are wrong.

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[EDIT:  I’ve put up a new analysis (24 March 2010) of Fodor’s argument here: Hypotheses Natura Non Fingo]

See a continuation of the argument against Fodor in What Fodor Got Wrong, and in Fodor’s Intensional Criticism of Evolution.

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* This is the argument I presented Fodor with during our brief conversation after his talk at CUNY.  He tried to block it by saying that Natural Selection is statistical, whereas General Relativity is not.  In my previous post, What Fodor Got Wrong, I argued that this position begs the question or is just wrong.

Posted in biology, evolution, fitness, General Relativity, measurement, philosophy, physics, science. Tagged with , , , , , , , .

What Fodor Got Wrong

Jerry Fodor recently (4 March) gave a talk entitled “What Darwin Got Wrong” at the CUNY Graduate Center in New York City.  He accused Darwin of committing the intentional fallacy and hence said, straight out, that he didn’t believe in the theory of evolution.

So what exactly does Fodor think Darwin got wrong?

He believes that the theory of evolution is vacuously true (or just wrong) and hence not a worthwhile theory of science.

You can sink your teeth into the argument in this synopsis, but be forewarned, the argument is good: you may, depending upon your convictions, be forced to disbelieve the theory of evolution.  However, it doesn’t identify all the critical presuppositions that Fodor uses (this is no fault of the synopsis; it is accurate to the argument), and these are what are really necessary to show where Fodor is mistaken.

[The one day, the ONE DAY, a year that there is a talk specifically having to do with my work on philosophy of science and biology and I have an international plane flight to catch only a few hours after the talk.  I happily was able to catch the whole talk but I couldn’t stay for the question and answer session.  So I did the only thing I could think of and asked my questions during the break and ran out of the building (literally).  The following quote is accurate as far as I can remember, and, as far as I know, I am the only one who heard him say it.]

Fodor said,

“Natural Selection is statistical. It just is.”

What does this mean?

In my world Natural Selection is a force.  It is a force that changes species over time.  For example lets take some species of bacteria.  A few of the bacteria in that species adapt to be able to eat a novel sort of food and this gives them an advantage over the others.  Eventually these bacteria are able to replicate more often and eventually most of the overall bacteria population has this trait.  Hence the species has changed from not having a certain property to having a certain property.  If you ask me what caused this change in the bacteria population, I would say that Natural Selection was the cause or force behind the change in the species.

There are two ways I can think of interpreting Fodor’s statement: 1) Natural Selection is statistical and not a force.  2) Natural Selection is statistical and a force.

Taking the first interpretation that Natural Selection is statistical and not a force, how are we to understand my little story about the bacteria above?  Perhaps: “The change in the physiology of certain bacteria statistically increased their fitness over the other bacteria.  Hence those bacteria were able to replicate more readily and eventually outnumber bacteria without that trait.”  The thing that changed the species was the increased fitness, which was caused by the physiological change.  Natural Selection was the result of this change and can be observed statistically by seeing how individual organisms with that trait were able to fair better than their compatriots.  Therefore Natural Selection is a non-causal description or explanation of how species change.

This is immediately problematic because a description or explanation is always describing or explaining something that already exists: it will always be vacuously true, e.g. snow is white if(f) snow is white, or it will just be wrong, e.g. snow is blue.  Therefore, by assuming that Natural Selection is statistical and not a force, we have begged the question against Natural Selection.

Now let’s take a look at option 2: Natural Selection is statistical and a force.

As a force Natural Selection is the cause of things.  Causes can work directly, such as one object striking another and causing it to change direction, or as a field does, by creating an environmental disturbance of some sort which affects the object.  Natural Selection falls (more or less) into the latter category: the environment changes and this causes species to change, to adapt.

Is Natural Selection statistical under this interpretation? No.  If Natural Selection acts in the way a field does, by changing the environment which then affects things in that environment, then at every point there is some local interaction between the field and the object.  Otherwise we have a theory of action-at-a-distance, i.e. one thing is causing something to happen without any way for us to identify the underlying process: a theory of magic.  If something is acting statistically, then it is acting at different places with no known connection between them.  However, evolution comes with a ready made theory of local interactions: every organism is constantly struggling for survival.  The struggle for survival ensures that there is a connection between Natural Selection and the environment.  Therefore if Natural Selection is a force, it cannot also be statistical.

[I can confirm that Fodor believed that the struggle for survival was not critical because earlier in our brief conversation he said that the struggle for survival was merely a metaphor.  I responded by saying that Natural Selection is a metaphor then too, but he disagreed.]

In conclusion, by assuming that Natural Selection is statistical and ignoring the local interactions in the struggle for survival, Fodor has begged the question against evolution.  As a statistical non-causal explanation, Natural Selection cannot act as a force in evolution.  Once evolution has lost it’s driving force, it no longer can function as a working scientific theory.  However, believing that Natural Selection is a non-causal explanation is unfounded.  The theory of evolution provides a method – the struggle for survival – that explains how Natural Selection causes change in species via the environment, and ignoring this is what Fodor got wrong.

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[EDIT:  I’ve put up a new analysis (24 March 2010) of Fodor’s argument here: Hypotheses Natura Non Fingo]

See a continuation of the argument against Fodor in  Dismantling Fodor’s Argument, and in Fodor’s Intensional Criticism of Evolution.

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