Tag Archives: science

On the defense of ‘Evolutionary and Newtonian Forces’

Dr. Ellen Clark, a.k.a. Philosomama, has written a good review of Velasco & Hitchcock’s Evolutionary and Newtonian Forces [no paywall], one of the first papers to appear in the new open access journal Ergo. She points out that although V&H are trying to show how evolutionary forces are well described by analogy to classical causal Newtonian forces, they very nearly prove their opponent’s — the statisticalist — position. However, she comes to their defense.

Briefly, the causalist position is that evolutionary forces are causal like the force of Newtonian gravity. Natural Selection is a causal force that acts on biological organisms. The statisticalist position claims evolutionary phenomena are just the statistical result of the underlying causal physical processes. Hence, for the statisticalist, evolutionary phenomena have no force of their own.

V&H want to argue that evolutionary forces are like friction or elasticity. Dr. Clark points out that these forces can be problematic for their view, as they too note:

As Velasco & Hitchcock acknowledge, friction and elasticity are usually thought of by physicists as emerging “from the aggregate statistical behaviour of more elementary forces in certain kinds of system.” … But this is grist to the statistical view’s mill, we might say. They argue that natural selection supervenes on more basic causal events, without adding any extra causal power of its own. So these critics might happily accept that evolutionary forces are analagous to non-fundamental Newtonian forces, whilst holding their ground on the claim that natural selection is not causal.

However, causalist vs. statistical isn’t what I would like to discuss here; see her review for more discussion. Instead I’d like to focus on her appeal to the unknown as a defense of V&H’s causalist position. She claims that it is OK to consider evolutionary forces causal, like Newtonian forces, because Newtonian forces are mysterious. Since Newtonian forces are mysterious, we shouldn’t privilege their causality and should grant that right to not well understood biological forces as well. She says:

If there is anything magical about thinking of natural selection as an overall force producing all the multifarious births and deaths that we actually observe, then it is in very good company lumped in with physical forces.

This is an example of my favorite fallacy, Ignotum Per Ignotius: explaining something unknown by appealing to something even less understood. Let me explain why this is really problematic for her defense and ultimately for V&H.

Imagine a statisticalist pointing to their analogies and explanations of evolutionary phenomena and saying, “Evolution isn’t mysterious at all, and we have a perfectly good statistical explanation right here. The only causality is in the underlying fundamental physics.” The evolutionary causalist is then in the uncomfortable luddite position of insisting, without reason, that we don’t understand evolution. Appealing to an analogy with physics that supports the causal position is question begging, if there is no deeper reason why this analogy holds other than it supports the claim that evolutionary phenomena are mysterious and hence causal. Therefore without some other reason to support the causal view of evolutionary phenomena, appealing to mysteriousness does not justify the causalist position.

Moreover, without a supporting causalist argument, V&H have done the statisticalist’s work for them. As noted above, they have gone and shown exactly how evolutionary phenomena are like statistical results of underlying forces.

Posted in biology, evolution, philosophy, physics. Tagged with , , , , .

An Introduction to the Game Theoretic Semantics view of Scientific Theory

What is a scientific theory?  In an abstract sense, a scientific theory is a group of statements about the world.  For instance the Special Theory of Relativity has, “The speed of light in a vacuum is invariant,” as a core statement, among others, about the world.  This statement is scientific because, in part, it is meant to hold in a ‘law-like’ fashion: it holds across time, space and observer.

The Popperian view is that we have scientific theories and we test those theories with experiments.  This means that given a scientific theory, a set of scientific statements about phenomena, we can deductively generate predictions.  These predictions are further statements about the world.  If our experiments yield results that run counter to what the theory predicts — the experiments generate statements that contradict the predictions, the theory did not hold across time, space or observer — then the theory eventually becomes falsified.  Else the theory may be considered ‘true’ (or at least not falsified) and it lives to fight another day.

The game theoretic semantics (GTS) view is that truth is the existence of a winning strategy in a game.  In terms of the philosophy of science, this means that our theories are strategic games (of imperfect information) played between ourselves and Nature.  Each statement of a theory is a description of a certain way the world is, or could be.  An experiment is a certain set of moves — a strategy for setting up the world in a certain way — that yields predicted situations according to the statements of the theory.  If our theory is true and an experiment is run, then this means that there is no way for Nature to do anything other than yield the predicted situation.  Said slightly differently: truth of a scientific theory is knowing a guaranteed strategy for obtaining a predicted Natural outcome by performing experiments.  If the strategy is executed and the predicted situations do not obtain, then this means that Nature has found a way around our theory, our strategy.  Hence there is no guaranteed strategy for obtaining those predictions and the theory is not true.

An example:

Take Galileo’s famous experiment of dropping masses off the Tower of Pisa.  Galileo’s theory was that objects of different mass fall at equal rates, opposing the older Aristotelian view that objects of greater mass fall faster.

According to the Popperian view Galileo inferred from his theory that if he dropped the two balls of different mass off the tower at the same time, they would hit the ground at the same time.  When he executed the experiment, the balls did hit the ground at the same time, falsifying the Aristotelian theory and lending support to his theory.

The GTS view is that dropping balls of unequal mass off a tower is a strategic game setup.  This experimental game setup is an instance of a strategy to force Nature to act in a certain way, namely to have the masses hit at the same time or not.  According to Galilean theory, when we are playing this game with Nature, Nature has no choice other than to force the two masses to hit the ground at the same time.  According to Aristotelian theory, when playing this game, Nature will force the more massive ball to hit the ground first.  History has shown that every time this game is played, the two masses hit the ground at the same time.  This means that there is a strategy to force Nature to act in the same way every time, that there is a ‘winning strategy’ for obtaining this outcome in this game with Nature.  Hence the Galilean theory is true: it got a win over the Aristotelian theory.

Why you might want to consider doing things the GTS way:

GTS handles scientific practice in a relatively straightforward way.  Theories compete against Nature for results and against each other for explanatory power.  Everything is handled by the same underlying logic-game structure.

GTS is a powerful system.  It has application to  game theory, computer science, decision theory, communication and more.

If you are sympathetic to a Wittgensteinian language game view of the world, GTS is in the language game tradition.

More on GTS:

http://plato.stanford.edu/entries/logic-games/
https://en.wikipedia.org/wiki/Game_semantics

Posted in game theory, logic, philosophy, science. Tagged with , , , , .

On Matthen’s Intelligibility Argument

Mohan Matthen’s post Teleology in Big Systems brought up two options explaining how someone — Tom Nagel in Mind and Cosmos — would choose a teleological explanation over a naturalistic one. The first, below, got me thinking:

First, he might be saying that though it is physically possible (by a fluke series of mutations, for example) for mentality to have come about, it would be better explained by teleology. (Let’s call this the “intelligibility” argument.)

Though Matthen was referring to doubts about Darwinism being sufficient to lead to consciousness, there is another way to understand this intelligibility argument. If we grant that consciousness is something very special, though not unphysical, someone might consider the laws of physics to be constructed, teleologically, to permit consciousness. This is to say that our physics is teleogically directed to account for consciousness. The claim is not that consciousness was necessitated by our physics, but that our physics must conform to allow the possibility of consciousness. What is one philosopher’s Nature is another’s Teleology.

Now, I can’t see any philosophical motivation for this outside of a very deep belief that consciousness is exceptionally special. But if we grant exceptional status to consciousness, then it wouldn’t be ridiculous to consider that our physics must somehow be subject to the requirements of consciousness instead of the other way around. Whereas there may be infinite other possible physics that do not allow for the possibility of consciousness, we live under a physics that does.

My immediate, knee jerk response to this sort of move is that it is just a semantic shift about the meanings of teleology and nature, nothing deeper. If what the teleologist means by teleology is what others mean by nature, then there is no difference of opinion, only word use.

However, this semantic response does not engage the motivation for the teleological argument. The motivation is that consciousness is exceptional. So, if the naturalist believes that consciousness is exceptional and entirely natural, then the naturalist is left with no natural explanation for why it is so exceptional. However the teleologist may say that consciousness is exceptional, subject to the laws of physics, but unsurprising, since the laws of physics itself are directed to allow for consciousness. Since the teleological account does a better job at explaining something as special as consciousness, it is preferable.

This conclusion about preferring the teleological explanation to the naturalistic one is based on the absolute assumption that consciousness is exceptional. But how exceptional must it be? Since we are making physics, and presumably the rest of science, subject to our assumption, then the reasons for our assumptions must then be ontologically more basic and more certain than our entire scientific understanding of the world.

Personally I do not have any basis for thinking consciousness is so special that all of science must be made to account for it. From my perspective, claiming that science must conform to consciousness is a post hoc ergo propter hoc fallacy, since I’d have to arbitrarily assume consciousness to be a fundamental substance and science to be constructed to allow for it.

However, there could be people who do have beliefs that strong. For them, they would not be arbitrarily assuming consciousness to be the more fundamental substance in the universe and hence it would follow that science should conform to it. Instead it would be a direct causal link: consciousness, therefore science that teleologically allows for consciousness. This kind of teleological naturalism is special in that it does not appeal to the unlikelihood or complexity of consciousness evolving, as is wont to happen nowadays, but is based on an ontological claim about consciousness. I don’t know if this is more defensible than the Intelligibility Argument based on likelihood, but, as it is different, perhaps it has a chance to fair better.

Posted in biology, design, evolution, ontology, philosophy, physics, science. Tagged with , , , .

Book Review: The Genial Gene

The Genial Gene: Deconstructing Darwinian Selfishness by Joan Roughgarden

In The Genial Gene Joan Roughgarden seeks to replace the competitive understanding of evolution, known as sexual selection, with a cooperative one. The first sentence of her book reads, “This book is about whether selfishness and individuality, rather than kindness and cooperation, are basic to biological nature” (p. 1).

So what is the argument? Taking this first line, she wants to conclude something about basic biological nature. To do this, one can either define what basic biological nature is and then use that definition to derive conclusions, or else survey the natural world and find the best interpretation for whatever empirical results were found. She opts for the latter strategy.

To this end she first surveys and compiles examples of what people consider to be evidence for sexual selection and argues that this evidence has been misconstrued or simply does not support the theory of sexual selection. Then she offers a few logical arguments against sexual selection with the aim to highlight contradictions within the theory.

She then develops her alternative, called Social Selection. Social Selection is fundamentally based upon cooperation, not competition, and she proceeds to reinterpret the empirical research with respect to cooperation. Given the results of this reinterpretation, she concludes that the cooperative approach provides a more accurate picture of the empirical data than the competitive approach. Therefore social selection, not sexual selection, is fundamental to biological nature.

Can this argument be maintained?

Her argument fundamentally turns on the interpretation of the empirical research. (If her logical arguments were strong enough to undermine sexual selection on their own, she would have dedicated more space to them. At best, in my opinion, they could raise questions about sexual selection, but are not inherently damaging enough, even if they are accepted uncontested, to force a major revision to sexual selection.) She interprets the research in terms of cooperation and her opponents are those who interpret the research in terms of competition. Roughgarden claims her interpretation is the correct one.

Insofar as she is making an inference saying her interpretation is the best conclusion, her argument fails. She readily admits that the defenders of sexual selection are able to consistently create explanatory fixes for apparent contradictions in the empirical research. Since they are able to explain the data, the fact that she is unsatisfied by their explanations (and likes her own better) is no grounds for convincing her opponents to give up their explanations. After all, they have history and authority on their side. Her coming up with better numbers, that is, having formulas that (she says) more accurately represent the research, is not a sufficient reason for discarding a theory that has held up for many years, especially one that continues to be an area of active research. So, she has not successfully argued that social selection should replace sexual selection.

However, if we consider a more modest conclusion, then Roughgarden may be able to maintain part of her argument. She makes the point that the core Darwinian theory does not include sexual selection; it is a later contribution (ppg. 3-4). This suggest that there may be theoretical room for cooperation in addition to competition. But how much room?

Now the interpretive problem that she set up cuts the other way. Instead of her trying to convince us that her cooperative interpetation of the empirical research is the correct one, we ask the competitive interpretation why it is the best one. Empirical research alone cannot support one conclusion over another: the data must first be interpreted before a conclusion can be reached. As mentioned above, sexual selection has history and authority on its side, but age and endorsements are not arguments for being the sole fundamental methodology of biological nature. Without history and authority, sexual selection proponents only have their ability to explain bioogical research, which is no more than Roughgarden has. Therefore, advocates of sexual selection have no further theoretical resources to support their claim that sexual selection is the fundamental method working in evolution.

This means that Roughgarden does succeed in part. Based on the arguments she provides she is unable to maintain that kindness and cooperation underpin evolution, but she is able to cut sexual selection down to her size. She has shown that it is possible to reinterpret biological research in terms that do not rely upon competition and that sexual selection has no special theoretical privelege. Therefore sexual selection proponents can no longer claim to be fundamental biological reality: even though Roughgarden was unable to fell their theory, they won’t be able to down her either, and so she has established theoretical room for cooperation in Darwinian theory.

Posted in biology, evolution, measurement, science. Tagged with , , , .

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 , , , , , .

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

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

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 , , , , , , , .

Revision and Hypothesis Introduction

Say we have some theory that we represent with a formula of logic.  In part it looks like this:

[1] …(∃z) … Pz …

This says that at some point in the theory there is some object z that has property P.

After much hard work, we discover that the object z with property P can be described as the combination of two more fundamental objects w and v with properties R and S:

[2] …(∃z) … Pz … ⇒ …(∃w)(∃v) … (Rw & Sv)…

Now lets say that in our theory, any object that had property P depended upon some other objects, x and y:

[3] …(∀x)(∀y)…(∃z) … Pz …

In our revised theory we know that objects w and v must somehow depend upon x and y, but there are many more possible dependence patterns that two different objects can have as compared to z alone.  Both w and v could depend upon x and y:

[4] …(∀x)(∀y)…(∃w)(∃v) … (Rw & Sv)…

However, let’s say that w depends on x but not y, and v depends on y but not x.  Depending on the rest of the formula, it may be possible to rejigger the order of the quantifiers to reflect this, but maybe not.  If we allow ourselves to declare dependencies and independencies, arbitrary patterns of dependence can be handled.  The forward slash means to ignore the dependency of the listed quantified variable:

[5] …(∀x)(∀y)…(∃w/∀y) (∃v/∀x) … (Rw & Sv)…

Besides the convenience and being able to represent arbitrary dependence structures, I think there is another benefit for this use of the slash notation:  theoretical continuity.  In formula [2] above, there is a double right arrow which I used to represent the change from z to w and v, and P to R and S.  However, I created this use of the double right arrow for this specific purpose;  there is no way within normal logic to represent such a change.  That is, there is no method to get from formula [3] to formula [4] or [5], even though there is supposed to be some sort of continuity between these formulas.

Insofar as the slash notation from Independence Friendly Logic allows us to drop in new quantified variables without restructuring the rest of the formula, we can use this process as a logical move like modus ponens (though, perhaps, not as truth preserving).  Tentatively I’ll call it ‘Hypothesis Introduction’:

[6]

  1. …(∀x)(∀y)…(∃z) … Pz …
  2. …(∀x)(∀y)…(∃w/∀y) (∃v/∀x) … (Rw & Sv)…      (HI [1])

The move from line one to line two changes the formula while providing a similar sort of continuity as used in deduction.

One potential application of this would be to Ramsey Sentences.  With the addition of Hypothesis Introduction, we can generalize the Ramsey Sentence into, if you will, a Ramsey Lineage, which would chart the changes of one Ramsey Sentence to another, one theory to another.

A second application, and what got me thinking about this in the first place, was to game theory.  When playing a game against an opponent, it is mostly best to assume that they are rational.  What happens when the opponent does something apparently irrational?  Either you can play as if they are irrational or you can ignore it and continue to play as if they hadn’t made such a move.  By using Hypothesis Introduction to introduce a revision into the game structure, however, you can create a scenario that might reflect an alternate game that your opponent might be playing.  In this way you can maintain your opponent’s rationality and explain the apparently irrational move as a rational move in a different game that is similar to the one you are playing.  This alternate game could be treated as a branch off the original.  The question would then be to discover who is playing the ‘real’ game – a question of information and research, not rationality.

Posted in game theory, independence friendly logic, logic, philosophy, science. Tagged with , .

Hypotheses Natura Non Fingo

Newton famously wrote [1] [2]:

I have not as yet been able to discover the reason for these properties of gravity from phenomena, and I do not feign hypotheses…  It is enough that gravity does really exist and acts according to the laws I have explained, and that it abundantly serves to account for all the motions of celestial bodies.

as a response to those who challenged him to provide causes of gravity.  He said, “Hypotheses non fingo,” or, “I feign no hypothesis,” or if you will, “I haven’t even a guess.”

Earlier in a letter he wrote:

That one body may act upon another at a distance through a vacuum without the mediation of anything else, by and through which their action and force may be conveyed from one another, is to me so great an absurdity that, I believe, no man who has in philosophic matters a competent faculty of thinking could ever fall into it.

These passages show that Newton recognized a fundamental causal problem within his theory: that although his mathematics described gravitational physics, it did not provide a causal explanation.  It was not until General Relativity 200 years later was this problem solved.

Recently another major fundamental theory of science has been accused of lacking the proper causal structure:  Fodor & Piatelli-Palmarini’s attack on evolution, What Darwin Got Wrong.  Consider what Fodor says in his recent reply to Block and Kitcher,

A mere chronicle of instances of adaptation would not therefore amount to a theory of adaptation. It would just be “natural history.” We haven’t the slightest doubt that Darwin thought that he had discovered a theory of adaptation. It was, to be sure, a pretty thin theory, as it would have to be in order to apply to evolving creatures as such, whatever their phenotypes and whatever their ecologies.

He is saying that evolution is a mere chronicle of natural history — not a cause of it — just as Newton’s gravitation described gravity without revealing its causal structure.  Later he says,

[Biologists should] give up on the project of finding a mechanism for evolution and study the fixation of adaptive traits case by case. Since all the evidence suggests that they are extremely heterogeneous, this should keep evolutionary biologists busy well into the indefinite future.

This means that biologists should give up on repairing evolution and just try to explain individual phenomena moving forward, just as physics moved forward even as Newton knew his theory was on metaphysical shaky ground.

Hence it is Fodor now saying, “Hypotheses non fingo,”  because he believes he can describe natural history accurately, but also has no guess as to what caused things to work out the way they did.

* * * * *

In light of this analysis, consider this statement from Block and Kitcher’s counter argument:

After our critique, Fodor and Piattelli-Palmarini have apparently decided that the crucial point is the lack of a “theory” of natural selection. But, as we have noted here, nobody needs a “theory” of the type they demand.

And this from Sober’s recent review [pdf]:

What is the net gravitational force now acting on the earth?  That depends on the mass of the sun, the moon, the stars, and of everything else.  It does not follow that there are no laws of gravity, only that the laws need to have numerous placeholders.  FP may object to my analogy because it is always the mass of these various objects and their distance from the earth that are relevant to the gravitational force that the earth experiences.  My reply is that this makes no difference…

Neither has understood the argument as presented above.  If Block and Kitcher had understood, then they would have recognized that yes, for the vast majority of people, the “‘theory’ of the type they demand” is unnecessary, but it is, nevertheless, of critical importance to the likes of Newton and Einstein.  If Sober had understood, then he wouldn’t have used the worst possible example to make his point:  by saying it is “always the mass of these various objects and their distance from the earth that are relevant,” and not mentioning motion, we know he was only thinking about Newtonian Mechanics.

* * * * *

Should we, with Fodor, believe that we are stuck in a philosophical absurdity?

No.  What I said in my original criticism of Fodor, found in What Fodor Got Wrong (18 March 09),  still applies.  Though the above description of the problem is likely clearer than my analysis based on his claims that Natural Selection is statistical and that the struggle for survival is only a metaphor, the problem of causal structure is the same.  My solution focuses on using individual struggles as local interactions of Natural Selection — like a gravitational field in General Relativity — and hence provides the causal structure that Fodor wanted.

[EDIT 6 April 2010:  I’m thinking I gave Fodor too much credit in this post.  I now think his arguments amount to saying that for each instance of evolution we have, we are merely relaying natural history, not a causal explanation.  The argument I attributed to Fodor above says that evolution by natural selection is natural history.  Fodor must be more agnostic about evolution’s ontology because of how he says it is possible to look for some alternative to natural selection in his reply to Block and Kitcher.  My solution is still viable though:  since I provide causal structure, this also provides how to describe evolution in a causal way.]

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