Questions about Evolution

[lucaspa]

Science proved that the aether could not be detected (by scientific investigation), which isn't exactly the same thing. Einstein just ignored it because of this, but never said it didn't exist.

 

No, the experiments proved the aether didn't exist because a consequence of the existence of the aether that should have been there wasn't. IOW, the aether was falsified.

 

What Lorentz did was try to save the aether from falsification by making an ad hoc hypothesis: the earth (and everything on it) contracted in the direction of motion thru the aether to counter the difference in the speed of light that should have been detected.

 

You can make an ad hoc hypothesis to save any and every theory from falsification. The key to a valid ad hoc hypothesis is that it is testable independent of the hypothesis it is trying to save. The Lorentz contraction has no other way to be tested because it's SOLE effect is to save aether.

 

"More careful reflection teaches us, however, that the special theory of relativity does not compel us to deny ether...To deny the ether is ultimately to assume that empty space has no physical qualities whatever". Albert Einstein

 

And Special Relativity, by itself, perhaps doesn't deny aether. It was the Michelson-Morely experiments that did so. Special Relativity doesn't need the aether, either, since light waves are propagated independent of a medium.

 

lucaspa: All you need do is feel that rocks sitting in the sun are warm.

 

Yes, but most of that heat is reflected into space.

 

Feeling the rocks only allows you to detect the radiation (and increased motion of the molecules and atoms of the rock). That most of the heat is radiated into space is irrelevant. It still has less capacity to do work (greater entropy) than the radiation that was absorbed by the rock.

 

Meanwhile, in plants some of the radiation absorbed made sugar, which is a decrease in entropy.

 

Yes, but the sugar is eventually emitted as heat, far more quickly than the reflected infra red photons ever will. Life is a great way of increasing entropy.

 

You said "eventually" and "far more quickly". You can't have both. The sugar can remain AS SUGAR for years! Meanwhile, the rock radiates its infrared within a few seconds or hours.

 

Also consider what happens when the sugar is burned. Some of that energy is used to make high energy phosphate bonds which are then used to synthesize proteins and nucleic acids -- reducing entropy. It is not until those compounds are broken down that entropy is finally equal to what the rock did within a few seconds or hours!

 

So no, life is a way of locally decreasing entropy.

 

Life, therefore evolution, is just chemical reactions.

 

Life does NOT = evolution. Or evolution does NOT = life. Evolution happens to populations of living organisms. Therefore you cannot say that evolution = chemical reactions. Evolution also happens to other populations.

 

But you are ignoring the rest of the reactions. While the rock is sitting there (in the dark, too) radiating away, what is the plant doing?

 

1. Storing some of the sugar.

2. Using some of the sugar in oxidative phosphorylation to make ATP and release heat.

3. Using the ATP to synthesize proteins and nucleic acids, which themselves represent a decrease in entropy.

 

Eventually all the decrease in entropy represented by the synthesis of the sugar will be used to do work + release heat and the compounds make will themselves be converted to heat.

 

As I said, since entropy is the ability to do work eventually maximum entropy will be reached -- a state where the energy is in a form that can do no more work. However, life is very inefficient at increasing entropy because, at each stage, life couples the release of energy to work and even decreasing entropy in another subsystem. The rock, OTOH, is very efficient at increasing entropy because it doesn't use the energy to do ANY work.

 

I would doubt that save for natural selection there is no real universal mechanism to why certain species display certain phenotypic characters overall.

 

There are indeed other mechanisms:

 

1. Genetic drift.

2. Development.

 

Genetic drift will cause a trait to be "fixed" (every member of the species has it) but this happens by pure chance.

 

Because the same genes are used to develop different parts of the body, genes selected by natural selection for one trait will also make traits in other parts of the body -- but without being selected.

 

Examples:

1. Male nipples in humans. Nipples are selected for in females but the genes are expressed during development in human males also.

2. Elongated ankle bones in pandas. Natural selection "fashioned" an elongated wrist bone as a "thumb". However, the same genes are expressed in hindlimb development as well, so all pandas have the corresponding bone in the ankle elongated.

 

Science can't figure out how to explain orderred changes in the genetics twhich can allow life to evolve lower and lower entropy. So it adds higher entropy within a mutation, that is now suppose to help lower entropy.

 

There is no problem. Mutations themselves are not necessarily either higher or lower entropy. Mutations are simply changes in the sequence of nucleotides within DNA. That in itself does not represent either an increase or decrease in the ability to do work. What really matters is the protein that is made from the translated DNA. That protein may have a different function.

 

Mutations that increase the amount of DNA -- single nucleotide insertions, insertions, gene duplications, inversions, or chromosome duplication -- make more nucleotide sequences that may mean more proteins.

 

In the case of a single nucleotide insertion of deletion, it is going to result in a radically different protein as the amino acid sequence of the protein is randomly changed. Usually this will produce a protein with a different biological function than the original protein. But that in itself has nothing to do with entropy.

[D H]

No, the experiments proved the aether didn't exist because a consequence of the existence of the aether that should have been there wasn't. IOW, the aether was falsified.

Stick to biology.

 

The MM experiments did not prove the aether didn't exist. It proved that the assumed behavior of the aether was incorrect. Lorentz developed the Lorentz-Fitzgerald contraction assuming an absolute reference frame and an aether that behaved in concordance with length contraction.

 

The Lorentz-Fitzgerald contraction is also derivable from Einstein's special relativity postulates, which reject the concept of an absolute reference frame. Since special relativity and Lorentz' formulation are mathematically identical, falsifying one would falsify the other. We prefer special relativity not because it predicts different results but because the predicted results are derived in special relativity from two very simple postulates. In contrast, length contraction is axiomatic in Lorentz' formulation. Physicists prefer simple and deep axioms.

 

What Lorentz did was try to save the aether from falsification by making an ad hoc hypothesis: the earth (and everything on it) contracted in the direction of motion thru the aether to counter the difference in the speed of light that should have been detected.

This ad hoc hypothesis fully explains the observed result. It had better explain it, because the exact same result is derived in special relativity.

[bombus]

No, the experiments proved the aether didn't exist because a consequence of the existence of the aether that should have been there wasn't. IOW, the aether was falsified.

 

I disagree. The experiment attempted to find 'suggested' effects of the aether and failed to detect any. However, the expts pre-supposed what the aether is. if the aether is more like pixels on a computer screen (for example) within which reality occurs, it's effects would be undetectable. That I think is kinda what Einstein was alluding to in his quote.

 

Feeling the rocks only allows you to detect the radiation (and increased motion of the molecules and atoms of the rock). That most of the heat is radiated into space is irrelevant. It still has less capacity to do work (greater entropy) than the radiation that was absorbed by the rock.

 

Meanwhile, in plants some of the radiation absorbed made sugar, which is a decrease in entropy.

 

You said "eventually" and "far more quickly". You can't have both

 

Yes I can. eventually means a few years or maybe centuries, and this is far quicker than reflected photons travelling through space for billions of years.

 

The sugar can remain AS SUGAR for years! Meanwhile, the rock radiates its infrared within a few seconds or hours.

 

years but not billions of them.

 

 

Also consider what happens when the sugar is burned. Some of that energy is used to make high energy phosphate bonds which are then used to synthesize proteins and nucleic acids -- reducing entropy. It is not until those compounds are broken down that entropy is finally equal to what the rock did within a few seconds or hours!

 

So no, life is a way of locally decreasing entropy.

 

I refer you to the answers above

 

 

 

Life does NOT = evolution. Or evolution does NOT = life. Evolution happens to populations of living organisms. Therefore you cannot say that evolution = chemical reactions. Evolution also happens to other populations.

 

You said that that the theory only applied to chemicals. Life is chemicals.

[iNow]

Bombus, can you please work on your use of quote tags? I find following your points very difficult because I have no idea who you are referencing until I go back and read the thread again. Thanks.

 

[quote name='MemberName']Comments from that member here[/quote]

Your response outside the tags.

[bombus]

sorry!

[Mr Skeptic]

pretty much the same.

 

basically, if you have information and you randomly change it, it will, over time, degrade -- not inprove.

 

however, evolution is not just random changes over time. evolution is random changes over time + a selection mechanism. it is the selection mechanism that basically weeds out the crappy changes and propagates the good ones, thus overcomming the natural 'degredation over time' that would normally be expected with random changes to information.

 

If you look at error catastrophy, which is basically where there are so many random changes that the evolutionary selection process becomes overloaded and stops working, then you can see the natural degredation over time occouring (well, technicly evolution still works during error catastrophy, it's just that evolution slows down the degradation, rather than eliminating it and allowing inprovement).

 

Consider evolutionary algorithms http://en.wikipedia.org/wiki/Evolutionary_algorithms

These are basically mutation and selection applied to the real world right now. They are, of course, artificial, but there are some good parallels. The information adding part is carried out by the fitness algorithm. Now the fitness algorithm has very little information, but the ability to recognize stuff that gives a good score. Also of interest is the manner in which the system is tuned (mutation rate, intermixing, etc).

 

Bonus: if you have someone who believes God created us through evolution, then our purpose is given by the selection criteria (ie to have as many surviving offspring as possible). So God's most important command would be: "Go forth, and multiply."

[pioneer]

One way to look at the evolution of life, in terms of gibbs free energy, is to compare modern species, from humans, to single cell life. We know the approximate pecking order, relative to what is advanced. We then do an energy efficiency survey and one should see higher forms of life have more efficient GFE.

 

The easiest way to approach this, the brain and muscles use the most energy intensive of the cells in the human body. The brain is especially so, constantly burning a lot of calories for a small amount of biomass. The muscles, as a whole may burn more, by they are 10-20 times the mass. If we normalize, per pound, then brain, which is universally understood to be the criteria of evolution, is what what converts the most Gibb's efficient free energy/weight the most efficiently.

 

I understand this creates a problem for conventional wisdom, which likes to think in terms of random and selective advantage. In this case, the random and selective advantage is not random, but follows a fairly direct relationship that lead to net improvements within the efficiencies.

 

For example, insects often have six legs, but animals ended with four. This was not some random mutation, it was simply more efficient. If evolution happened again, it would still evolve the same thing not due to some mutation, but becuase of higher efficiency in lowering free energy. Multicellular sort of distributes the tasks in such a way that all parts are able to achieve efficiency while also making the entire bio-unit greater than the sum of the parts, individually.

 

An interesting life form is cancer. This can really burn energy, mostly because cancer stays within the most energy intensive state of a cell's life cycle, which is during the creation of new cells. With cancer, the entropy falls at a very fast rate, to create rapid orderring into more and more cells. It is not multicellular, in the traditional sense of an animal. But it could be a state of cell mass that might have evolved into multicellular. In other words, it sort reaches the single cell energy maxima, requiring the next step to be able to take the lowering of free energy, to higher efficiency.

[lucaspa]

The MM experiments did not prove the aether didn't exist. It proved that the assumed behavior of the aether was incorrect.

 

The "assumed behavior" IS the aether. IOW, the aether exists in the sense that it DOES such and such. If the consequences don't exist, neither does the entity.

 

Lorentz developed the Lorentz-Fitzgerald contraction assuming an absolute reference frame and an aether that behaved in concordance with length contraction.

 

I addressed the Lorentz contractions. Notice that "assume". It "assumes" a length contraction exactly of the right amount to counter the movement thru the aether! It is an ad hoc hypothesis meant to save the aether from falsification. Ad hoc hypotheses can be either valid or invalid. The ad hoc hypothesis of Neptune to save Newtonian mechanics from falsification by the orbit of Uranus was valid. Why? Because the hypothesis could be tested independent of the theory it was trying to save. That is, testing for the existence of Neptune involved optics, not Newtonian mechanics.

 

The Lorentz contraction has no other effect than to save aether from falsification. That makes it an invalid ad hoc hypothesis.

 

The Lorentz-Fitzgerald contraction is also derivable from Einstein's special relativity postulates, which reject the concept of an absolute reference frame. Since special relativity and Lorentz' formulation are mathematically identical, falsifying one would falsify the other.

 

Reference? This is essential to your argument. As far as I can see, they are NOT "mathematically identical".

 

"To explain this null result, George Fitzgerald, an Irish physicist, put forward in 1889 an ad hoc hypothesis that the distance L parallel to the Earth’s motion should be contracted by an amount sufficient to make the two times equal. Independently, Hendrik Lorentz, in Holland, put forward the same hypothesis in 1904, but he based it on the fact that electromagnetic forces between charged particles are sensitive to their motion and cause a minute contraction in the size of moving bodies, just enough to explain the null results of the Michelson-Morley experiment." http://www.sc.doe.gov/Sub/Newsroom/News_Releases/DOE-SC/2005/TIME.htm

 

Now, you may mean that the result -- the "contraction" -- is identical. Notice above that Fitzgerald and Lorentz got the "contraction" by a very different method than SR.

 

"Einstein was aware of the results of the Michelson experiments, and did not accept the explanation of these results by Lorentz in terms of a force, and associated contraction, exerted on objects moving through the aether." http://www.pas.rochester.edu/~dmw/ast102/Lectures/Lect_06b.pdf

 

Lorentz used a force. Einstein didn't. Instead, he simply postulated that the speed of light is the same for all observers no matter the frame of reference. Lorentz did have the speed of light vary, but had the length change.

 

We prefer special relativity not because it predicts different results but because the predicted results are derived in special relativity from two very simple postulates. In contrast, length contraction is axiomatic in Lorentz' formulation. Physicists prefer simple and deep axioms.

 

I've seen this before. It's wrong. You don't evaluate theories based on simplicity. We prefer special relativity because it does predict different results AND because testing finds the results that SR predicts, such as clocks being different in different gravitational fields or E = mc^2.

 

Well if we agreed that life uses energy from the system to delay (or even temporarily reverse) the effects of 2nd law of Thermodynamics, it's effect is to increase the overall entropy of the universe.

 

No, it doesn't. Entropy has a maximum independent of life. That is, if no life exists, the universe would still reach maximum entropy. Therefore life doesn't increase the overal maximum entropy. In the short term, the overall entropy increases despite life. That is, the entropy of the larger system increases more than life decreases entropy in the smaller system.

 

Life decreases the size of the entropy increase.

 

Life captures solar energy and ultimately converts it to heat better than a bare rock would (less reflection, convertion of photons to heat...),

 

No, Bombus. Life converts light to heat worse than a rock. The rock converts as much of the light to heat as possible immediately. Life takes some of the light and makes sugar instead of making heat.

 

In the end, both life and the rock end up getting the same increase in entropy. But since efficiency is a function of time, the rock is much more efficient than life.

 

Bonus: if you have someone who believes God created us through evolution, then our purpose is given by the selection criteria (ie to have as many surviving offspring as possible).

 

But this is NOT the selection criteria. This is the RESULT of selection, not the criteria. The "criteria" are the requirements of the environment, which can only be met by a subset of designs. Not every design will do the necessary job/criteria. Those individuals that do meet the criteria -- are lucky enough to be born with the correct design -- will have more surviving offspring than those individuals that did not have as good designs.

 

So God's most important command would be: "Go forth, and multiply."

GIGO.

 

There are some incorrect assumptions about evolution here:

One way to look at the evolution of life, in terms of gibbs free energy, is to compare modern species, from humans, to single cell life. We know the approximate pecking order, relative to what is advanced. ... If we normalize, per pound, then brain, which is universally understood to be the criteria of evolution,

 

1. There is no "pecking order" in evolution. An amoeba is just as "evolved" as a human. Both species have 3.8 billion years of evolution behind them. The amoeba is just as adapted to its environment as humans are to theirs.

 

2. Brains are NOT the criteria of evolution. EVERY adaptation comes with a cost as well as a benefit. There are no universally good traits. If our brains lead to technology that makes H. sapiens extinct, then the amoeba's "simplicity" would be a better "criteria of evolution".

 

For example, insects often have six legs, but animals ended with four. This was not some random mutation, it was simply more efficient. If evolution happened again, it would still evolve the same thing not due to some mutation, but becuase of higher efficiency in lowering free energy.

 

Actually, the 6 legs of insects IS a mutation. It has been documented: 1a. http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/vaop/ncurrent/full/nature716_fs.html Hox protein mutation and macroevolution of the insect body plan. Ronshaugen M, McGinnis N, McGinnis W. Nature 2002 Feb 21;415(6874):914-7

 

It's just that 6 legs worked out better for insects in their particular environment. But notice we still have centipedes and millipedes.

 

Evolution and natural selection are a merger of contingency and determinism. You are forgetting contingency and trying to make evolution purely deterministic.

 

Vertebrates ended up with 4 limbs, but that is also a mutation and what was selected for in that particular environment. Notice that whales and dolphins are more efficient without all 4 limbs.

 

Multicellular sort of distributes the tasks in such a way that all parts are able to achieve efficiency while also making the entire bio-unit greater than the sum of the parts, individually.

 

An interesting life form is cancer. This can really burn energy, mostly because cancer stays within the most energy intensive state of a cell's life cycle, which is during the creation of new cells. With cancer, the entropy falls at a very fast rate, to create rapid orderring into more and more cells. It is not multicellular, in the traditional sense of an animal. But it could be a state of cell mass that might have evolved into multicellular.

 

You've got to be kidding, right? Cancer evolve to multicellular? Cancer is NOT a "life form". It is a loss of control within a life form. But no cancer exists independent of the organism it originates in. When the organism dies, so does the cancer. In order to be a lifeform, an entity must be able to exist independently. Calling cancer a "lifeform" is like calling skin a "lifeform".

[D H]

I've seen this before. It's wrong. You don't evaluate theories based on simplicity. We prefer special relativity because it does predict different results AND because testing finds the results that SR predicts, such as clocks being different in different gravitational fields or E = mc^2.

 

Special relativity does not predict that clocks are different in different gravitational fields. That is the domain of general relativity, not special relativity. LET and special relativity are mathematically equivalent, right down to E=mc². Physicists do evaluate theories in part based on simplicity. Physicists prefer special relativity over LET in part because Einstein used simpler and deeper axioms that generate Lorentz contraction while Lorentz contraction is merely axiomatic in LET. LET is ugly while special relativity is elegant. Physicists strive for aesthetics in their theories.

 

Move forward in time to general relativity. One reason Einstein delayed publishing was that he wanted a theory that postdicted known results (the precession of Mercury) and at the same time did not need any special scale factors. The end result only has one "magic number", the universal gravitational constant G.

[pioneer]

The cancer exists as long as its environment is able to support it. If a human was placed in the desert, and was not adapted to it, he would not be lifeform for long, either. I am not pro-cancer or anything, but cancer is like many lifeforms, having become specialized to an environment. As long as its human eco-system is stable, it prospers and multiplies. It also has a selective advantage, within the human eco-system. If we didn't interceed for the weaker cells, it would dominate the environment. It has the genetic change, plus selective advantage, criteria for evolution, if one assumes an amoeba is as evolved as a human being. Multicellular is rated higher, which is why we fight cancer and not delight in its strength.

 

Cancer is an example of a genetic change with a very distinct selective advantage, both working together, leading to a de-evolutionary state. The genetic-selective advantage criteria is a two edge sword. The combo can imply forward or backwards progress. It depends on the environment.

 

One could argue that although evolution moves forward over time, selective advantage can act as much as a drag as it can a pull. As a human example, monarchies are often portrayed as good blood lines, which was the old way of saying good genetics, before we called it genetics. They knew it was due to the breeding process. Yet this selective advantage, was often a drag on the progression of humanity. It could, at times, be a cancer, that would eat a culture into extinction.

 

Monarchies were able to set up an environment, that gave them selective advantage. This could have required keeping the people poor, hungry, tired, uneducated and afraid. It is very likely, that better genetics were among the subjects, due to less inbreeding, but the environment was designed, by the king, to give selective advantage to the king. It is possible, since human can alter the environment to favor themselves, genetics and selective advantage will often break down, except in very long term cycles. Hstory shows a gradual progress inspite of the constant drag, due to selective advantage not always equaling evolution.

 

A classic example was Copernicus. He could prove the earth went around the sun. This should have been placed him at selective advantage. But the environment resulted in him being detained until his death bed. This would have alterred the environment, such that those who had selective advantage in the old environment, had an uncertain future. The choice was to keep the environment the same and let evolution wait. This is probably why evolution is so slow. Genetics is often the pawn in the selective advantage game of chess.

[dichotomy]

In order to be a lifeform, an entity must be able to exist independently. Calling cancer a "lifeform" is like calling skin a "lifeform".

 

Do all of the microbes in the environment of the human body survive independently of it? I’d think they could survive in a Petri dish environment. Is there any form of cancer that can survive in a Petri dish environment? And if so, does this then make it a lifeform?

[DrDNA]

.....but cancer is like many lifeforms, having become specialized to an environment. As long as its human eco-system is stable, it prospers and multiplies. It also has a selective advantage, within the human eco-system. If we didn't interceed for the weaker cells, it would dominate the environment. It has the genetic change, plus selective advantage, criteria for evolution, if one assumes an amoeba is as evolved as a human being. Multicellular is rated higher, which is why we fight cancer and not delight in its strength. .

The only thing that cancer has in common with evolution is mutation.

Cancer is a mutation that leads to DEATH. There is no selective advantage and no evolution in death.

 

What the.....the rest of what you wrote (about monarchies and stuff) is REALLY out there dude........

 

Is there any form of cancer that can survive in a Petri dish environment? And if so, does this then make it a lifeform?

 

Plenty of cancer cells are grown in "Pitre dish environments". Thousands of (even commercially) available cell lines originated in the bodies of cancer patients.

Are they a "lifeform"? Wow. Interesting question, but probably not.

Along similar lines. Would you consider the millions of endothelial cells that your body sheds from you digestive system everyday (insert flushing sounds here) a "lifeform"? We can grow them in Pitre dishes also.

[dichotomy]

Plenty of cancer cells are grown in "Pitre dish environments". Thousands of (even commercially) available cell lines originated in the bodies of cancer patients.

Are they a "lifeform"? Wow. Interesting question, but probably not.

Along similar lines. Would you consider the millions of endothelial cells that your body sheds from you digestive system everyday (insert flushing sounds here) a "lifeform"? We can grow them in Pitre dishes also.

 

I was trying to understand Lucaspas statement that was - "In order to be a lifeform, an entity must be able to exist independently." (Pioneer's speculation of cancer being a lifeform prompted this statement)

 

What constitutes a lifeform seems highly debatable to me.

[immortal]

Do all of the microbes in the environment of the human body survive independently of it?

 

Ah! here is the point, an organism is like an ecosystem for a microbe as our surroundings is to us. As lucaspa stated when an organism dies the cancer cells also die but all the microbes living in the body don't die they have a greater chance of finding a different ecosystem. If cancer cells would have got the ability to live in a different ecosystem then yes you can call this as a life form. Of course they replicate in petri dishes because they have an enzyme called telomerase which provides the immortal property for cancer cells but remember this is artificial.

 

If evolution happened again, it would still evolve the same thing not due to some mutation, but becuase of higher efficiency in lowering free energy.

 

With cancer, the entropy falls at a very fast rate, to create rapid orderring into more and more cells.

 

Well if you rewind the tape of evolution and run it again it is very unlikely that you will get the same thing again. Because the mutations that happen to an organism are random you can't expect a DNA molecule to change its configurations at the right time and in the right organism so that you get the same design solutions. Even in your words evolution can take different pathways to create designs which have high efficiency in lowering free energy. So different pathways means different design solutions and hence they will look different. But yes there is a greater chance for similar stuffs evolving but not same stuffs.

 

Just because cancer cells create more cells that does'nt mean a derease in entropy. Because all the molecules in cells have similar configurations and they have similar entropy values. So if a single cell becomes two, the two cells which are formed will have similar entropy values of the original because both the cells are made of same molecules with same configurations.

 

Order and entropy are not same but related and the equation which relates entropy and disorder is Boltzman's entropy equation S = K ln D, where D is the measure of disorder. In statistical mechanics you need to specify the microstates (i.e. collection of states of all the molecules in any moment) and these collection of microstates leads to a macrostate. Entropy is a measure of finding a specified microstate in the next measurement. So more is the number of microstates (i.e DISORDER) more is the uncertainty in finding that microstate in that moment so more is the entropy.

 

In case of cells the molecules in a cell will remain in that microstate if you look at it in any moment so there is no uncertainty in finding that microstate and it makes no sense to measure the entropy of the cell. Even in a mutation just the configuration of the DNA molecule will change but the entropy of the DNA will remain similar as it is made up of same set of combination of atoms.

[Dak]

If anyone's looking for the stuff about the sun getting smaller and evolution being a load of cacky poop, it's been split to here

 

because it was crap.

[pioneer]

The entropy change for cancer, is one cell inputting small materials. with higher level of disorderring. It then orders these into proteins, DNA and RNA to form another daughter cell. The difference between mother and daughter state doesn't change much entropy. But from small food molecules to another daughter cell, the change of entropy is quite high.

 

If you look cancer within the human body, it stems from cells that are part of a multicellular organism. Each cell type is differentiated, which limits which genes are used. The cancer has all the genes needed to make a basic multicellular lifeform, but stays as a single cellular entity. If it could shuffle the working genes, into those used by a lymphocyte, then the cancer would become a viable lifeform. Cancer has all the genes, needed to be a viable single or multicellular lifeform. But genes alone, is not enough. It needs to get the genes to change their differentiation to become alive. Potential genetic advancements can lie dormant, unless these genes are able to find their way into the active genetic grid.

 

My long ramble about selective advantage was trying to show how selective advancement doesn't always have to coordinate with the most progressive genetic state. Let me give an example, say there was a group of tough dinosaurs. Genetic advances that give selective advantage may need to be connected to making dino offspring bigger, stronger, faster, damage resistant, etc. Say one of the dino's offspring mutated a semi-advanced voice box, that allowed him to generate a more advanced array of sounds. Although this is advanced genetically, and could lead to language improvements, this behavior will be odd to the rest. He is the ugly duckling, that the dominant member may need to kill. He would have been better off with a simple genetic improvement, such as a thicker skull, in that particular environment. Selective advantage does not always go to the best genetic improvements, unless these happen to be useful in that environment.

 

Here is an interesting thought, how about a president's exam. The person with the highest overall score in intelligence, ingenuity, statemanship, etc., becomes the president for the next four years. This would be closer to using a genetic type criteria to define who has top selective advantage. Current selective advantage would never let this happen, since many in power may not be among the final contestants. Currently, we are asked to pick among smooth talking entertainer types. I am not saying he/she who becomes president, from this batch, are not qualified. Only they are the most qualified in the environment, created by the current selective advantage. The genetic choice would have to alter the environment, so that person could gain even more selective advantage. But the current selective advantage would resist. It would be an interesting polarization between genetics and selective advantage for dominance. Genetics would only have the power of the presidency protecting it from extinction. But with that singular selective advantage pinacle, genetics may overcome.

 

It is sort of like the dino example, with a huge neighboring Dino (power of the presidency) , saying, " I like the odd noises that little dino makes. If anyone touches him, I will deal with them personally. All the other dino's, will hate this at first. But as the new noises starts to grow on them, they begin to distiquish the sounds and learn to make their own sounds. Before long, this is the way of the future. Genetics just needed an intersession.

[foodchain]

Just to add the ecology of life is very important in regards to defining a species, simply put natural selection for a example and adaptations to a niche. One other point simple yet possibly overlooked is that the ecology accounts for biotic factors also, such as it did not go from microbes the highest level troph with nothing in between, which of course is nothing more then another physical aspect of evolution. The nitty gritty details are part I guess of the entire whole, such as giving a certain area why are bacteria more likely to gather on a certain surface area before others, or even the reaction or adaptation really over time to various hardness of surface areas, but that’s trailing off the point I think. Species of squid I think another fine example of such, that via the organisms entire lifespan or even development is relational to different but used regularly depths of the ocean. Such as at certain depths is where an offspring of a squid may spend X amount of time as it develops, this relates to other variables also, such of course as pressure and temperature, but its typically not a perfect of exact number down to microseconds; which among others things such as environment is another aspect of evolution, such as the awesome amount of variation in human appearance.

 

Selective advantages that persist of course stay alive for lack of better words in organisms, such as the neuron for example, or a liver or any other various long lasting organs or organelles. Such as sight, its around in a multitude of organisms, but from insects, to birds, to humans its easy to see that such is open to evolution. How this relates from any particular angle, from the molecular to the ecological is rather wide I would say for angles of study, but from a standpoint of how to define an organism of course is tricky, one simple example would be asking if it simply reproduces, but of course for an entire multicellular organism I don’t think its typically looked upon as each cell being its own being, but that all goes back to more and more questions.

[lucaspa]

Special relativity does not predict that clocks are different in different gravitational fields. That is the domain of general relativity, not special relativity.

 

No, it's SR. http://www2.slac.stanford.edu/vvc/theory/relativity.html

"One of the strangest parts of special relativity is the conclusion that two observers who are moving relative to one another, will get different measurements of the length of a particular object or the time that passes between two event"

 

So, until you can get SR right, I'm afraid I have to be very skeptical of such statements as " LET and special relativity are mathematically equivalent, "

 

Physicists do evaluate theories in part based on simplicity. Physicists prefer special relativity over LET in part because Einstein used simpler and deeper axioms that generate Lorentz contraction while Lorentz contraction is merely axiomatic in LET. LET is ugly while special relativity is elegant. Physicists strive for aesthetics in their theories.

 

I think you have confused 2 things: formulating theories and evaluating them. Theory evaluation is the process of deciding whether a theory is accurate or false. That is done solely on data.

 

Physicists may "strive for aesthetics" but that doesn't mean they decide the validity of a theory on its aesthetics. Just look at Feynman's "sum over paths" approach or M Theory. Not at all aesthetic. The history of physics shows that many physicists have made statements regarding simplicity and aesthetics: Freeman Dyson comes immediately to mind. However, when it comes down to really evaluating theories, that is always done on the data.

 

Move forward in time to general relativity. One reason Einstein delayed publishing was that he wanted a theory that postdicted known results (the precession of Mercury) and at the same time did not need any special scale factors. The end result only has one "magic number", the universal gravitational constant G.

 

This doesn't negate what I said. Yes, physicists try to make the theory as simple as possible. We all do. However, when it comes to evaluating competing theories, that is done on the data. If the more complicated theory explains the data better, then that is the one considered valid.

 

The cancer exists as long as its environment is able to support it. If a human was placed in the desert, and was not adapted to it, he would not be lifeform for long, either. I am not pro-cancer or anything, but cancer is like many lifeforms, having become specialized to an environment.

 

Apples and oranges. Pioneer, a human is an organism. Cancer is an aberrant cell WITHIN an organism. Cancer is no more a lifeform than a multipotent adult stem cell (MASC) is. Both have an unlimited growth potential but neither can exist as an independent organism. Remember, cancer and MASCs are PART of an existing organism.

 

As long as its human eco-system is stable, it prospers and multiplies. It also has a selective advantage, within the human eco-system. If we didn't interceed for the weaker cells, it would dominate the environment. It has the genetic change, plus selective advantage, criteria for evolution, if one assumes an amoeba is as evolved as a human being. Multicellular is rated higher, which is why we fight cancer and not delight in its strength.

 

It is not rating multicellularity "higher". Cancer does not have a "selective advantage" in terms of evolution, because it kills the ability to transmit alleles to the next generation by killing the organism. Remember, humans reproduce by germ cells, not cancer cells.

 

Cancer is an example of a genetic change with a very distinct selective advantage, both working together, leading to a de-evolutionary state.

 

There is no such thing as a "de-evolutionary" state. Cancer is a disease of the individual that kills the individual. Think instead of an endothelial cell that produces plaque that clogs a coronary artery. This isn't evolution, it's a malfunction within the organism. Or think of rheumatoid arthritis, where the immune cells attack the other cells of the body. This isn't an evolutionary advantage for the immune cells, it's a malfunction of those cells.

 

One could argue that although evolution moves forward over time, selective advantage can act as much as a drag as it can a pull.

 

You are suffering from the idea that there is "progress" in evolution. That simply isn't true. Evolution is adaptation of the population to an environment. To have "move forward" you have to make a non-scientific judgement call as to what constitutes "forward". For instance, is the blind mole rat an evolutionary move "forward" because it is adaptation to living underground our is it a move "backward" because it is the loss of the eyes?

 

Monarchies were able to set up an environment,

 

You cannot look at monarchies as biological evolution! The kings had no selective advantage over any other person. In fact, if you look you see that kings often had LESS children than their subjects.

 

The choice was to keep the environment the same and let evolution wait.

 

It's not that evolution is "waiting", but consider what happens when the environment IS stable. Once a population is well-adapted to that environment, then any change is going to be less adapted. So now you have a different form of natural selection operating: purifying or stabilizing selection. It will act to eliminate variation because only a few sets of alleles will be best in that particular environment.

 

Pioneer, PLEASE do some reading on evolution!

 

Well if you rewind the tape of evolution and run it again it is very unlikely that you will get the same thing again. Because the mutations that happen to an organism are random you can't expect a DNA molecule to change its configurations at the right time and in the right organism so that you get the same design solutions. ... But yes there is a greater chance for similar stuffs evolving but not same stuffs.

 

There is considerable data to support "similar stuffs evolving but not" identical creatures.

 

Parallel evolution demonstrates that similar environments will produce similar adaptations. This is because environments are design problems and there are only so many designs that will work. Thus sharks, ichthyosaurs, and dolphins all have the same general shape. The wolf and Tasmanian wolf have the same general shape. So, given the limitation of environments and limitations of physics, it is possible for natural selection to invent the same general pattern again and again.

 

On the other level, some experiments have shown that even specifics are done the same:

Speciation in action Science 272:700-701, 1996

1. L. Rieseberg, B. Sinervo, C. Linder, M. Ulngerer, D. Arias, Science 272, 741 (1996).

What happened was that the researchers produced in the greenhouse the genetic changes leading to the formation of a naturally occurring species of sunflower. The species is Helianthus anomalus and molecular evidence suggested it was formed by recombinational speciation of H.annuus and H. petiolarus. This is a process in which two species hybridize, and the mixed genome of the hybrid becomes a third species that is reproductively isolated from its ancestors.

 

So what the researchers did was hybridize H. annuus and H. petiolarus and produced 3 independent hybrid lines undergoing different regimes of mating to siblings and backcrossing to H. annuus. After 5 generations the DNA was analyzed for comparison to the wild type and to see which ancestral genes persisted in the hybrids. It matched with the wild type. Remarkably, despite the different crossing regimes, all 3 lines converged to nearly the identical gene combinations. The gene recombinations were complex, but repeatable in all 3 hybrid lines.

 

The fact that the genes in the lab hybrid matched wild H. anomalus indicates that artificial selection and natural selection both selected many genes for fertility rather than adaptations to the environment.

 

The fact that all 3 hybrid lines converged to nearly identical genetic content and these matched the wild type (a 4th hybrid line) shows that several paths of evolution in this case reach the same point. As Jerry Coyne says in discussing the research "In Helioanthus, however, the sequence of evolutionary change is largely repeatable over both the long and short term: When this tape is rewound, it plays pretty much the same program."

 

Just because cancer cells create more cells that does'nt mean a derease in entropy.

 

Correct. Pioneer is looking ONLY at the decrease in entropy of proteins, DNA, etc. He figures if there are more cells, then there are more proteins, DNA, etc. and thus more decrease in entropy.

 

BUT, if we look at the level of the ORGAN or TISSUE, cancer represents an INCREASE in entropy. Cancer is LESS ordered than the tissue or organ that it replaces. A prime example are teratomas. These have a multitude of tissues in them, but they are not ordered as they are in the human body. You have a disordered mixture of teeth, cartilage, intestine, skeletal muscle, blood vessels, etc.

 

The entropy change for cancer, is one cell inputting small materials. with higher level of disorderring. It then orders these into proteins, DNA and RNA to form another daughter cell. The difference between mother and daughter state doesn't change much entropy. But from small food molecules to another daughter cell, the change of entropy is quite high.

 

Pioneer, this is what I thought you were doing. Nice of you to confirm it! Look above to what I said about the organ or tissue.

 

The cancer has all the genes needed to make a basic multicellular lifeform, but stays as a single cellular entity. If it could shuffle the working genes, into those used by a lymphocyte, then the cancer would become a viable lifeform.

 

No, it wouldn't. Because a lymphocyte is not a "viable lifeform", either. It can't pass on its genes to the next generation because a lymphocyte is only one cell type in a multicellular organism.

 

There is a difference between "alive" and "viable lifeform". That's part of the confusion here. To be alive an entity must 1) metabolize, 2) respond to stimuli, 3) grow, and 4) reproduce. By that criteria, both cancer cells and lymphocytes are "alive". But that doesn't make them a viable lifeform. The entire multicellular organism that is a human is the viable lifeform. The individual cell types cannot exist on their own. Now, there are, of course, unicellular organisms that are viable lifeforms. It's just that single cells within a multicellular organism are not.

 

Here is an interesting thought, how about a president's exam. The person with the highest overall score in intelligence, ingenuity, statemanship, etc., becomes the president for the next four years. This would be closer to using a genetic type criteria to define who has top selective advantage.

 

But genetics are not the only criteria for a successful president! You also have to consider the role of environment is shaping experience and learning how to be an effective politician!

 

Yes, you can persuasively argue that the current system does not favor the best politician but favors other characteristics. However, that doesn't mean the "test" will do any better! The only way to evaluate who is and who is not an effective politician is to let them participate in politics!

[D H]

No, it's SR. http://www2.slac.stanford.edu/vvc/theory/relativity.html

"One of the strangest parts of special relativity is the conclusion that two observers who are moving relative to one another, will get different measurements of the length of a particular object or the time that passes between two event"

The statement you quoted does not talk about gravity or about how time varies because of a gravitational field. It talks about time dilation because of motion. Guess what? That is exactly what LET talks about as well. SR cannot address the behavior of a clock in different gravitational field because SR is limited to inertial reference frames. Hence the disclaimer "special". General relativity, published a decade later, covers all reference frames. That is why it is "general".

 

Physicists may "strive for aesthetics" but that doesn't mean they decide the validity of a theory on its aesthetics.

Did I ever say that? I said that even though LET and SR are equally up to the task of explaining the Michelson-Morley experiment, we prefer SR in part because of its aesthetics. Given two theories that are indistinguishable mathematically but are very different in formulation (i.e., the underlying axioms), which would you prefer?

 

I know this is off-topic, but you started it. Like I said in my first post in this thread, stick to biology.

[BenTheMan]

No, it's SR. http://www2.slac.stanford.edu/vvc/th...elativity.html

"One of the strangest parts of special relativity is the conclusion that two observers who are moving relative to one another, will get different measurements of the length of a particular object or the time that passes between two event"

 

Lucaspa---This is not correct. SR doesn't know about gravity, only GR does. All of the calculations done in special relativity are done at a constant acceleration. General relativity gives you the ability to do calculations with acceleration, and (therefore) in a gravitational field.

 

I think you have confused 2 things: formulating theories and evaluating them. Theory evaluation is the process of deciding whether a theory is accurate or false. That is done solely on data.

 

Physicists may "strive for aesthetics" but that doesn't mean they decide the validity of a theory on its aesthetics. Just look at Feynman's "sum over paths" approach or M Theory. Not at all aesthetic. The history of physics shows that many physicists have made statements regarding simplicity and aesthetics: Freeman Dyson comes immediately to mind. However, when it comes down to really evaluating theories, that is always done on the data.

 

In the absence of any distiguishing characteristics, we select a theory based on how simple it is. The example that jumps to mind is some calculations I did for a Relativistic Quantum Mechanics class when I was getting my master's degree... The calculations were very difficult, and I couldn't figure out how to do them. I found out that using quantum field theory, the calculations were MUCH easier. So I taught myself enough QFT to do the calculations, and received only half credit on the exercizes, because I ``missed the point''.

 

The thing is, no one used relativistic quantum mechanics if they can help it, even though it gives the same answer. Everybody knows how to use QFT, so that's how we do it.

 

And I object to calling the Feynman sum over paths inelegant. Which path does the electron take? ALL paths, of course!

 

Aside from this, maybe someone can catch me up, without having to read 5 pages of prose...Why are we talking about phsyics here? Presumably, someone brought up the point of competing theories, and used an example from physics?

 

What I don't understand is why I see talk of ethers, which were disproved 100 years ago... The only types of ethers which are allowed are the types with no reference frame. Which means you can't detect them. This is a bit like saying that evolution is driven by an intelligent designer, you just can't detect her.

[ydoaPs]

How did we get from evolution to SR/GR/QFT?

[BenTheMan]

How did we get from evolution to SR/GR/QFT?

 

That's what I was asking.

 

Presumably people are trying to support ``intelligent design'' using some example from physics---specifically (I think) Lorentz Ether Theory and Special Relativity. The comparisson is wrong on several levels, but mostly because of General Relativity. Special relativity is what you get when you do general relativity without acceleration---if general relativity is the first principle, then special relativity is a consequence. This is not true about Lorentz Ether Theory---one cannot derive LET from GR. IF that is the claim, then I would be very interested to see the derivation.

 

So, I'm still confused.

[Martin]

How did we get from evolution to SR/GR/QFT?

 

it started here:

http://www.scienceforums.net/forum/showpost.php?p=358186&postcount=62

 

Bombus was talking about the 2nd Law of Thermodynamics and in passing reference used the somewhat poetic phrase "eddies in spacetime"

 

Then Lucaspa quarreled with the use of that phrase, and said he must be talking about Einstein gravity and what in the world did "eddies in spacetime" mean.

 

So bombus replied

 

Aaahhh, well, they exist but cannot be detected. Matter is a result of eddies in the flow of spacetime, just like peacocks tails and tigers stipes are the result of eddies in the flow of eco-energy. I have absolutely no scientific proof of this whatsoever, but science would not be capable of proving it either way anyway. A bit like the ether.

 

And the mention of ether spawned another branch of argument. At least that is how it looked to me on brief inspection.

[iNow]

At least that is how it looked to me on brief inspection.

Geesh, if that's how things look to you on "brief inspection," I shudder to think of what you're capable upon deep reflection for long duration. Nice job, mate.

[Martin]

Thanks!