Category Archives: science

Genetic Drift and the Uncertainty Principle

I have previously argued that the history of species must be treated like a evolutionary trajectory: we can only appreciate a species in a relative sense, just as we must evaluate physical trajectories relative to our own motion.

But what happens when we try to measure the very small in physics?  We find there is a limit to the precision at which we can measure, as given by the uncertainty principle.

This suggests that there may be some similar limit when it comes  to measuring small changes in species.  The more we try to pin down exactly what a species is, the less sure we will be about its future and the more we measure the direction the species is heading, the less sure we will be about exactly what constitutes that species.

If genetic drift is just another way of saying that we cannot pin down the exact genetic make-up of a species then drift may be considered to be an instance of the uncertainty principle.

and HAPPY NEW YEAR

Posted in biology, evolution, measurement, philosophy, physics, Relativity, science.

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.

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

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.

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

A Priori Against Physicalism

I saw that Richard Brown is working to defend physicalism against a priori arguments.  He says that most (all?) arguments use the same intuitions found in the zombie-knowledge arguments.

This got me to thinking about a priori arguments against physicalism and I came up with something different:

If physicalism is, as Dr. Brown says, “… the view that only physical things exist. Physical things are those things that are postulated by a completed physics,” then I wonder who made physics king?  I’d have to assume that there is something within science that specifies physics as most fundamental.

However, science itself, or more specifically philosophy of science, is discipline agnostic.  There is nothing within the basic structure of science to specify physics as the foundation.  Maybe it is biology that is fundamental, maybe it is psychology, maybe something else; the point is that there is no a priori reason to prefer one over any of the others.  If there is nothing that distinguishes physics as a ground for the other sciences, then there is no reason that physicalism should be taken as a fundamental philosophy.

At this point the physicalist would want to find some grounds for the claim that physics is fundamental.  This is problematic though: nothing could be used from within physics because that would be question begging.  On the other hand, if we try to justify physics as fundamental by appealing to something outside physics, then isn’t that thing that provides the justification more fundamental than physics itself?  If we have to justify the claim ‘physics is fundamental’ by appealing to something even more fundamental, then physics is no longer fundamental because it needs an outside justification.  Therefore any justification for physicalism is inherently question begging or self-contradictory.

I know I haven’t disproved physicalism; at best I’ve indicated that justifications for it are bad.  And if any justification is bad, then the position is indefensible.  Since most philosophers don’t like to hold indefensible positions, perhaps this is sufficient.

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

What Science Ignores

I was skimming the philosophy blogs today and came across “Should Scientific Methods and Data be Public?” over at It’s Only A Theory (and Brains for that matter).  Gualtiero Piccinini argues that scientific matters ought to be made public.  My first thought was, “What exactly does G.P. mean by public?” and my second was, “Anyone who doesn’t think scientific methods should be public is bat-shit crazy.” (Yes, I get angry about this stuff.  And from here on out, I’m using my own version of ‘public’, which is likely compatible with G.P.’s, but I do not want to look like I am putting words in Gualtiero’s mouth.)

Let me explain.

When practicing science we are ignoring, in part, at least three important things: time, space, and people.  Science is, in some respects, atemporal: we believe that if everything else is held the same, it doesn’t matter when we conduct our scientific experiments.  There is no scientific difference between an experiment performed this week and an experiment performed years ago; we can replicate the experiments of the masters and get the exact same results they did (within experimental error of course).

Secondly, science is, in some respects, separate from space:  we believe that if everything else is held the same, it doesn’t matter where we conduct our scientific experiments.  There is no scientific difference between an experiment performed in New York or in Shanghai; we can replicate experiments of scientists all over the world and get the exact same results they did.

Lastly, science is, in some respects, separate from particular people: we believe that is everything else is held the same, it doesn’t matter who is conducting our scientific experiments.  There is no scientific difference between an experiment that I have performed and one that someone else performs; anyone may replicate an experiment and get the exact same results as someone else.

This, among other reasons, is what makes science so great:  a scientific discovery will last beyond your life and your laboratory and can travel the world indefinitely.  Unlike a great performance (theater or sport, take your pick), it will be exactly replicable for all time.

Now, back to scientific methods being public.  If a scientific method is private, then it means that one or more of the three points listed above is being violated.  Either the experiment is limited to the people who performed it (only certain people can make it work), the experiment is limited to the time in which it was performed (it only worked that one time) or the experiment is limited to the place it was performed (it only works in my basement).  Once one of the three above points can no longer be ignored, then we have lost that which makes science so impressive.

Insofar as people are afforded the right to use language as they wish, I suppose it is acceptable for someone to call an experiment that violates one of the three above points science, or maybe, scientific.  I, however, hold that what is generally thought to be science necessarily requires that the above three points not be violated.

Posted in philosophy, science, time. Tagged with , .

Happy Birthday, H. C. O.

Today, as Google/Wikipedia tells me, is Hans Christian Ørsted’s birthday.  He coined the term ‘Thought Experiment’ and, if he had done nothing else, I’d still think he ought to be remembered far and wide.

Posted in philosophy, physics, science.

The Non-Reducibility & Scientific Explanation Problem

Q: What is a multiple star system?

A: More than one star in a non-reducible mutual relationship spinning around each other.

Q: How did it begin?

A: Well, I guess, the stars were out in space and at some point they became close in proximity.  Then their gravitations caused each other to alter their course and become intertwined.

Q: How did the gravitations cause the courses of the stars to become intertwined?  Gravity does one thing: it changes the shape of space-time; it does not intertwine things.

A: That seems right.  It is not only the gravities that cause this to happen.  It is both the trajectory and mass (gravity) of the stars in relation to each other that caused them to form a multiple star system.

Q: Saying that it is both the trajectories and the masses in relation to each other is not an answer.  That is what is in need of being explained.

A: You are asking the impossible.  I have already said that the relation is non-reducible.  I am not going to go back upon my word in order to reduce the relation into some other relation to explain it to you.  The best that can be done is to describe it as best we can.

Here is the problem: If you have a non-reducible relation (e.g., a 3-body problem or a logical mutual interdependence) then you cannot explain how it came to exist.  Explaining such things would mean that the relation was reducible.  But being unable to explain some scientific phenomenon violates the principle of science: we should be able to explain physical phenomenon.  Then the relation must not be non-reducible or it must have been a preexisting condition going all the way back to the origin of the universe.  Either you have a contradiction or it is unexplainable by definition.

What can we do?  You can hold out for a solution to the 3-body-problem or, alternatively, you can change what counts as explanation.  The latter option is the way to go, though, I am not going into this now.

For now I just want to illustrate that this problem of non-reducibility and explanation is pervasive:

Q: What is a biological symbiotic relationship?

A: More than one organism living in a non-reducible relationship together.

Q: How did it begin?

A: Well, I guess, the organisms were out in nature and at some point they became close in proximity.  Then their features caused each other to alter their evolution and become intertwined.

Q: How did the features cause the courses of their evolution to become intertwined?  Physical features do one thing: they enable an organism to reproduce; they do not intertwine things.

A: That seems right.  It is not only the features that cause this to happen.  It is both the ecosystem and the features of the organisms in relation to each other that caused them to form a symbiosis.

Q: Saying that it is both the place the organisms are living in and their features in relation to each other is not an answer.  That is what is in need of being explained.

A: You are asking the impossible.  I have already said that the relation is non-reducible.  I am not going to go back upon my word in order to reduce the relation into some other relation to explain it to you.  The best that can be done is to describe it as best we can.

As you can see, I am drawing a parallel between a multiple body problem and multiple organisms that live together.  Like the star example above, there is no way to explain the origins of organisms living together.  Even in the most basic case it is impossible.

Posted in biology, epistemology, evolution, independence friendly logic, ontology, philosophy, physics, science. Tagged with , , , , , .

Aether Propeller?

I was trying to figure out how planes stay in the sky.

So this is what I came up with.

wing

As the plane moves forward, a small vacuum is created above the wing. The vacuum is a low pressure zone which pulls the wing up and the air down to fill itself in (because Nature HATES a vacuum).  This upward pull that the low pressure zone creates we call lift.

I thought, “Hooray.  This isn’t so complicated!  Planes stay up because they create small vacuums above their wings as they move forward, creating an upward force.”

Then I thought, “And this is why planes can’t fly in outer space, because there is no air to displace and create a vacuum.”

Then I thought, “But if there is an aether theory, why not?”

wing2

So as a wing moves through a vacuum, generally we don’t think there is anything to cause lift or drag.  But if we have an aether theory of a vacuum, i.e. there is some substance below what we can observe that our matter exists within, then why can’t we create a vacuum in that substance?

My line of thought was: Air is to Vacuum as Vacuum is to Black Hole.

Can’t we just spin a propeller fast enough in outer space to create lift?  As the prop turns small vacuums in the aether will be created, and, insofar as Nature hates vacuums, a force will be created to fill in this vacuum, pulling the propeller in that direction.

(Someone please tell me how this is nonsense so I won’t go around thinking I’ve come up with a new model of space flight.)

Posted in fun, physics, random idiocy, science, technology. Tagged with , , , .

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.

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