Split from Pro/Anti Evolution Debate

[John Cuthber]

 

I suppose that if you define "fit" as the natural characteristics that allow an individual increased probability of having more off-spring then even "evolution" is a virtual tautology. The problem is the reality is hiding behind the terms.

 

Even identical twins are essentially different in all possible ways. If they both have green flecks in their eyes then maps of these flecks will not coincide. One will have a stray brown fleck and the other blue flecks. I'm simply saying that the "fitness" of these two individuals will vary greatly in many extinction events due to the very subtle nature of these events.

As far as I can tell, you are beginning to get to grips with the reason why individuals don't evolve, but groups do.

An individual's reproductive success is, largely, a matter of luck.

But if some individuals within a group possess some trait that tends to improve their success, then that trait will (almost inevitably) be more strongly represented in the next generation.

[Ten oz]

I suppose that if you define "fit" as the natural characteristics that allow an individual increased probability of having more off-spring then even "evolution" is a virtual tautology. The problem is the reality is hiding behind the terms.

 

Even identical twins are essentially different in all possible ways. If they both have green flecks in their eyes then maps of these flecks will not coincide. One will have a stray brown fleck and the other blue flecks. I'm simply saying that the "fitness" of these two individuals will vary greatly in many extinction events due to the very subtle nature of these events.

 

You are not factoring in random happen stance. Most species will go and have gone extinct. Of those who did not often it was right place at the right time. There is no adapting when a volcano blows your environment up. Evolution is a zero sum game. The cream is not constantly rising to top. Today for example we are living in a time of mass extinction. We are witnessing an extinction rate that is a thousand times faster than natural rates. Yet while some animals are being pushed by humans into extinction other ones are being purposefully spared. Cows and Pigs for example have nothing to worry about. Humans think they are tasty. Meanwhile polar bears which are far more intelligent and mobile than Cows are heading up that preverbal creek without a paddle.

[cladking]

 

But if some individuals within a group possess some trait that tends to improve their success, then that trait will (almost inevitably) be more strongly represented in the next generation.

 

Yes, we never disagreed on this. I'm still of the belief that the differences that improve chances of survival are exceedingly subtle because the cause of evolution, extinction events, have very subtle mechanisms.

 

I'm aware that evolutionary theory is not merely that the fast, strong, healthy, and smart survive but I'm of the opinion that these traits while of benefit to the individual and to the gene pool play very little role in change of species which is really change in indiduals from a generational perspective.

 

If two pairs of identical twins produce off spring then these will be nearly as dissimilar to one another as any two random individuals. If one twin is killed in an event and the other isn't then his off spring will tend to be very different because his new mate will share the genetic subtlety that saved them. Of course this is all very dependent on the nature of the cause and the degree to which this nature differentiates between the genetics and the physical expression of the genetics as it manifests in individuals. Random events will cause no change in species but there is never really truly random causes of death because all life is individual and all individuials are their genetic material.

[John Cuthber]

"Yes, we never disagreed on this. I'm still of the belief that the differences that improve chances of survival are exceedingly subtle because the cause of evolution, extinction events, have very subtle mechanisms."

http://en.wikipedia.org/wiki/Dodo#Extinction

People ate the dodos

 

http://en.wikipedia.org/wiki/Passenger_pigeon#Extinction

People ate the pigeons

And here's a whole bunch of others

http://en.wikipedia.org/wiki/Extinction_event#Most_widely_supported_explanations

 

Where, exactly, is the subtlety?

[Delta1212]

 

I suppose that if you define "fit" as the natural characteristics that allow an individual increased probability of having more off-spring then even "evolution" is a virtual tautology.

Yes, it is. It's a logically necessary consequence of any system of patterns that reproduce with variation for this exact reason.

[cladking]

You are not factoring in random happen stance.

 

Certainly much of nature is random. One rabbit survives while healing a broken leg because it just happens to keep its odor away from a fox while it's healthy brother inadvertantly stumbles into a badger's den. Almost everything has many characteristics of being random. A pendulum swings back and forth and its state at any time can be predicted. Most thing however are not so easily predicted so we tend to see them as being random. But they simply are not. Even the mass extinctions to which ytou refer are not really randome because they affect primarily individuals which are in places that are ideal to be transformed into human habitat. If they become extinct in these areas it's irrelevant to that species as a factor in species change dependent on that specific local population. However the reality will tend to be very different and when looking at the survivors and the fatalities on an individual basis then differences in their behavior and genes will become apparent. Humans tend to open new habitat by first improving water systems and then buildiong roads. Individuals dependent on prey or habitat along good routes for roads will be preferentially selected to be killed. If the odds of survival increase after these initial deaths then any surviving population will be relatively devoid of the genes that express by living in flatter and lower terraine.

 

We see randomness because we see "rabbits" rather than an animal with the genes of rabbits named "Fluffy". Rather than analyzing the cause of the various deaths and trying to determine how some survive, we see randomness. If we look at any event where an animal dies we see randomness because just as all life is individual all death is individual as well. We see the cheetah catch the rabbit but we don't see that the rabbit wouldn't have been caught if it llived closer to the savannah or if it preferred daisies to daffodils. What we see as "random" is everything but random. Nature can simply select for rabbits that like some specific foiod and these individuals will breed true and are different than their grandparents.

 

Species change thus is very sudden.

 

 

Where, exactly, is the subtlety?

 

 

 

The subtlety died with the last number of indivuals who were sufficient to constitute a viable "population".

 

While these last thirty or forty individuals were all dodo birds they most probably shared genetic traits that had kept them alive. If they had actually survived and the populations began to recover the new species would be different along these parameters. They might not have even looked a lot like their great great grandparents.

Yes, it is. It's a logically necessary consequence of any system of patterns that reproduce with variation for this exact reason.

 

I'm not certain I take your meaning so hesitate to comment.

[Arete]

Ok, I'm going to have to bow out in order to stop procrastinating and get on with an NSF pre-proposal, but I'd like to point out a few more inaccuracies in what you're saying, in the hope of providing better understanding:

 

All behavior and all structure of an individual is dependent on genetic information.

 

This is untrue: The phenotype (i.e. structure and behavior) of an organism is a product of genotype AND environment. Two identical genotypes, exposed to different environments can result in different phenotypes e.g. http://www.nature.com/hdy/journal/vaop/ncurrent/full/hdy201492a.html

 

 

Each individual is wholly and utterly unique and "fitness" is in no real sense beneficial to survival except in relatively stable biological niches and "populations".

 

This is untrue. Human genomes are largely identical across populations http://www.nature.com/scitable/topicpage/using-snp-data-to-examine-human-phenotypic-706. When you look at gene expression (which should be highly driven by the environment), 25% of expression differences are between populations rather than individuals within populations. http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1004549

 

The second statement is entering not even wrong territory. Fitness is important in any population undergoing selection.

 

Stable niches do not spawn much change in species so "fitness" isn't relevant to evolution. Rather what changes species are events that merely seem to be "random" from our perspective but are actually highly selective of specific genes and the expression of those genes.

 

This pair of statements appear to be contradictory. Fitness isn't relevant, but the environment selects for particular genes and expression profiles? If the environment is selecting specific genes/alleles, the fitness of those genetic elements is inherently important.

 

 

I'm sure you have me at a decided disadvantage here since my knowledge on such subjects is not extensive.

 

I really think you should pick up an introductory evolution or population genetics book. I think it would clear up a lot of the misunderstandings you're having, and you'd find it extremely interesting. If you want some recommendations, feel free to PM me.

 

The fossil record shows some species undergoing minor changes over very long periods and others that show rather large changes over shorter periods. But in all cases, even where there is significant sample sizes, there appear to be rather sudden changes. ie- there are "missing links' in all species. Horses show a relatively smooth development but certainly not man or giraffes. "Natural selection" or whatever name one chooses to call it can't seem to account for such changes except by suggesting mutation. Logically this doesn't seem to make sense. Why would a long necked giraffe just happen to be born at a time when the trait was required for the species to eat higher leaves? This sounds like the hand of God rather than logic.

 

The model you're talking about is called punctuated equilibrium. It's not a new idea, it's actually been around for 40 years or so. You're correct in that it wouldn't make sense if populations experienced no environmental fluctuation, and never migrated. However in light of what we know about how the environment has changed in the past, and how organisms have moved around the planet, punctuated equilibrium is perfectly consistent with evolutionary theory.

 

In addition, Giraffes didn't "suddenly appear". The Giraffidae fossil record is actually pretty good, and shows that evolution of the modern giraffe appears to have occurred over an 8 million year period, and giraffe like animals have been around for about 25 million years http://www.tandfonline.com/doi/abs/10.1080/00359190309519935#.VLP0CyvF98Mand was likely to be influenced strongly by sexual selection http://bill.srnr.arizona.edu/classes/182/Giraffe/WinningByANeck.pdf as well as browsing. No 'Goddidit' needed.

 

 

Some of the things I've observed concerning change in short lived species are not easily explained so I hesitate to use them as evidence but one thing seems pretty consistent; they revert back to "normal" if left alone for a few generations. This is because landing on the tops of things is the best way nature has found for houseflies to be. The "fittest" housefly is a housefly. When the new species came to be it intermingled with the old and was mostly lost. The genes are still there but the descendents behave normally.

 

 

Ok, so in your housefly "experiment" I doubt you would observe much actual evolution. A single housefly generation is typically 2-4 weeks, so you'd have to conduct an experiment for an inordinately long time to observe a quantifiable genetic change. For comparison, our lab works on viruses which infect bacteria. We can typically expect ~6-12 generations per day, dependent on the particular virus. Our experiments typically run for 2-6 weeks to observe quantifiable changes. Similar drosophila experiments (generation time is about a week) run for months, so a proper housefly experiment would have to run for a year or more to base any conclusion on.

 

Even so, by killing flies, you applied selection pressure, then when you removed the selection pressure, the flies reverted back to the "pre selection" phenotype. That's perfectly consistent with mainstream evolutionary theory.

 

I'm suggesting that there was an event that caused giraffes with genes that support shorter necks to die. I don't believe this has to be anything like what we imagine it to be or what would "make sense" to us. Perhaps something occurred that greatly favored individuals with the greatest difference in the size of front and back legs. Perhaps the same genes that express this large difference also creates the structure of the neck. The individuals that survived this event all looked like the normal "proto-giraffe" but their off spring were giraffes. There was no missing link so no missing links can ever be found.

 

Perhaps it was merely some sort of hoof fungus that created the giraffe. The number of possibilities is endless.

 

Given we have actual data, we can generate hypotheses based on educated guesses, but you're right, it could very well have been a selection pressure we haven't considered that caused giraffes to evolve the way they did.

 

 

Look at the domestication of dogs and other animals. These were all apparently very sudden transformations caused by intentionally selecting for characteristics. Nature does the same thing in essentially the same way in population bottlenecks. Rather than selecting specific characteristics, nature merely kills off all individuals without those characteristics. Nature seems to act randomly but actually is just using very subtle selection processes. All individuals of a species occupy the same niche and all are equally well adapted but when the niche changes then new characteristics are favored.

 

This is confusing - you're concluding by saying you accept that natural selection acting on variation in a population does result in diversification?

[cladking]

Fitness is important in any population undergoing selection.

 

 

I'll try to address your argument later if I can (if my knowledge base is sufficient) but I know in advance this is going to be the sticking point.

 

So long as you define "fitness" as the ability to survive then by definition the fit survive. It simply doesn't matter that the individual lives and deaths have never been studied in depth because it is assumed from the begiining that those most "fit" survive without ever defining "fit" in the real world except as the cause of evolution. Like most arguments this is assuming the conclusion.

[iNow]

Why are you trying to force everyone to use a nonstandard definition of fitness? If you must redefine terms for your argument to hold, then perhaps your argument is bunk. Wouldn't it be more appropriate for you to update your own thinking based on how the term is actually used by actual experts in the field currently under discussion?

[Delta1212]

 

I'll try to address your argument later if I can (if my knowledge base is sufficient) but I know in advance this is going to be the sticking point.

 

So long as you define "fitness" as the ability to survive then by definition the fit survive. It simply doesn't matter that the individual lives and deaths have never been studied in depth because it is assumed from the begiining that those most "fit" survive without ever defining "fit" in the real world except as the cause of evolution. Like most arguments this is assuming the conclusion.

Except that the word "fitness" isn't an argument. Stating that those individuals who survive are the survivors isn't assuming a conclusion, it is stating a fact.

 

You're free to argue against that fact if you want, but if your argument was predicated on the belief that everyone meant something else by "survivors" then you perhaps weren't arguing against what you thought you were arguing against, and there isn't an argument at all. It certainly doesn't mean that the other side is cheating in their definitions.

Edited January 12, 2015 by Delta1212

[cladking]

Why are you trying to force everyone to use a nonstandard definition of fitness? If you must redefine terms for your argument to hold, then perhaps your argument is bunk. Wouldn't it be more appropriate for you to update your own thinking based on how the term is actually used by actual experts in the field currently under discussion?

 

It's not the idea conveyed by the concept of the word "fitness" with which I have a problem. It is the utter lack of a hard definition for the term in any instance. We can define a situation in which every individual has an equal chance of survival execept based on a specific attribute such as strenght, speed, or intelligence. But in the real world mother nature doesn't hold races for rabbits nor administer IQ tests. The real world simply isn't like this. There is NEVER a fair test of fitness administered by nature. Some individuals have the cards stacked in their favor despite theire "fitness" and some are doomed to failure because of things beyond theior control and knowledge.

 

By defining "fitness" as the ability to survive you are assuming the conclusion; that the fit pass on their genes but others don't. This definition is the product of the perspective of the observer and has no basis in reality. From the definition change of species springs rather than from the means by which species actually change. The concept of species change being from fitness comes from the inside of the observer and is an artefact of language and has nothing to do with nature. We don't have the level of knowledge required to determine the reality though it's quite possible an experiment can be designed to show "survival of the fittest" doesn't (or does) work. But the experiment will require two things not normally done in this type of experiment. Each individual life and death as well as the predicted odds of survival must be computed and the stress placed on the population must be something real world rather than the type that destroys randomly. Nature is never truly random and this is why the computations and perspective fail. Events and situations that stress "populations" will be inconsequential to some highly unfit individuals and fatal to the fittest. This is the way of nature. If you just identify the survivors as the fit ones in practice or theory then you are assuming the conclusion. If you introduce random stessors then, yes, the "fittest" will survive because each individual has been affected exactly the same.

 

To prove evolution you must show that natural stresses actually selectively kill the unfit and spare the fit. You must be able to predict in advance which will die aand all this must happen under controlled condiitions where none of the cobnclusions have first been assumed. Breeding a poison resistant fruit fly and showing that these are "fitter" in a toxic enviroment than their normal cousins simply won't do it.

 

Observation alone might not cast any light on this because observation takes place from a perspective and it's the perspective that is problematical. Until it is really understood what makes two individuals different "survival of the fittest" might not even be falsifiable. I believe that logic and observation weigh against it for the many reasons I've already ennumerated. Nature simply doesn't play by any rules in an infinitely complex world. We percieve rules that don't exist because we extrapolate what we know and what we've learned. Only rules that can be isolated in the lab are real and they are only real on the large scale and briefest time. Then we see only the harmonic half of reality. The real world is chaotic and rules are mere suggestions and life exists only as individuals.

 

Probably all of nature's rules are probably exceedingly simple but they combine to make an impossibly complex reality. You can't simplify life to study it. You can breed it or change it but there's no more such a thing as an "average" bacterium than there is an "average" hydrogen atom. Just as no hydrogen atom is more "fit" than another, no rabbit is more "fit" than another. It's mere hubris that says we can legitimately call survivors "fit". When hydogen burns every atom doesn't have an equal probability of combining with oxygen. It depends on the oxygen atom and the precise orientations and trajectories and God knows what else. Any hydrogen atoms left over are not more fit than those which were consumed (combined).

 

Reality is infinitely complex. Our knowledge is derived from simple experiment.

[iNow]

It's not the idea conveyed by the concept of the word "fitness" with which I have a problem. It is the utter lack of a hard definition for the term in any instance.

Except, it has been defined. Even right here in this very thread. Several times, in fact.

 

Here's another:

http://en.wikipedia.org/wiki/Fitness_%28biology%29

[cladking]

Except, it has been defined. Even right here in this very thread. Several times, in fact.

 

Here's another:

http://en.wikipedia.org/wiki/Fitness_%28biology%29

 

 

OK. Now define it without using a reference to ebvoilution or some concept derived from evolution. Define it without reference to an "average" rabbit or be prepared to prove such a creature exists.

 

You can't because "fittest" is a word with no referent in nature. As such it has no meaning. It is akin to saying "God" changes species or that God selects which individuals live and die. There's no evidence for "God" or "fitness". You are invoking the conclusion when the term is used.

[Delta1212]

 

 

OK. Now define it without using a reference to ebvoilution or some concept derived from evolution. Define it without reference to an "average" rabbit or be prepared to prove such a creature exists.

 

You can't because "fittest" is a word with no referent in nature. As such it has no meaning. It is akin to saying "God" changes species or that God selects which individuals live and die. There's no evidence for "God" or "fitness". You are invoking the conclusion when the term is used.

No one is claiming that fitness is some tangible attribute that determines who lives and who dies. It's a metric of reproductive success.

 

From this, we can extrapolate that traits which are shared by many fit infividuals may have contributed to their fitness, and then from there attempt to determine why. But a "fit" individual is still just an individual that has successfully reproduced and "fitness" is just the state of being a successful reproducer.

[cladking]

But a "fit" individual is still just an individual that has successfully reproduced and "fitness" is just the state of being a successful reproducer.

 

 

I'm actually surprised you don't see the problem with this definition.

 

Words are invented to differentiate between objects and ideas. You're saying survivors survive.

"Look at the domestication of dogs and other animals. These were all apparently very sudden transformations caused by intentionally selecting for characteristics. Nature does the same thing in essentially the same way in population bottlenecks. Rather than selecting specific characteristics, nature merely kills off all individuals without those characteristics. Nature seems to act randomly but actually is just using very subtle selection processes. All individuals of a species occupy the same niche and all are equally well adapted but when the niche changes then new characteristics are favored."

 

 

 

This is confusing - you're concluding by saying you accept that natural selection acting on variation in a population does result in diversification?

 

What I'm trying to say is that natural population bottlenecks operate similarly to the way dogs were domesticated. The tamest wolves were interbred and the new species originated very suddenly. Nature does this exact same thing by selecting traits that are generally considered trivial to the ability to survive. Monkeys might be selected on their ability to identify the source of sounds or humans on their ability to hold water in their hands. Diversification isn't so much affected because every individual is diverse and most genes will survive population bottlenecks anyway. Even when lots of genes are eliminated most populations are local and the off spring of the survivors (bred by mother nature) will blend back in and increase diversification in the entire species. If populations are sufficiently large and sufficiently widespread diversificartion is nearly automatic (except for humans).

 

The biggest difference in our view here is probably that you think that surviving bottlenecks is the result of positive attributes of individuals while I believe they are trivialities like being tame or preferring a specific food. Even the tamest wolf wouldn't have come down to eat human garbage if it preferred some other type of food. Suvivors don't share single traits or single genes but clusters of genes. And none of it has to do with being predisposed to survival, they are merely the genes being favored by the stressor. It appears random but is very highly complex.

 

 

Ok, so in your housefly "experiment" I doubt you would observe much actual evolution. A single housefly generation is typically 2-4 weeks, so you'd have to conduct an experiment for an inordinately long time to observe a quantifiable genetic change. For comparison, our lab works on viruses which infect bacteria. We can typically expect ~6-12 generations per day, dependent on the particular virus. Our experiments typically run for 2-6 weeks to observe quantifiable changes. Similar drosophila experiments (generation time is about a week) run for months, so a proper housefly experiment would have to run for a year or more to base any conclusion on.

 

Even so, by killing flies, you applied selection pressure, then when you removed the selection pressure, the flies reverted back to the "pre selection" phenotype. That's perfectly consistent with mainstream evolutionary theory.

 

 

Many of my experiments are very long running. I also have anecdotal reports of other such experiments and observations over time. They don't carry a lot of scientific weight perhaps but the observations are framed in science. It seems very instructive to me that species can "adapt" to virtually anything. It appears this adaptatiuon is caused by presense of genes that can come to the fore because other individuals are killed. While the population drops the amount of habitat and food per individual soars increasing their odds of survival. Even though the trait being selected fore can't be predicted in advance usually. Even in retrospect it can be difficult to ascertain just what killed populations.

 

Our 17 year locusts (cicadas) in this area just failed a few years back. I'd guess about a 99.999% population reduction. I had expected a failure but not of this magnitude. This is just the nature of nature; nothing is static. Perhaps evolution would be slightly better phrased as "failure of the unfit" but this still misses the mark because those that fail are merely more typical and they are usually typical in ways that can not be readily identified.

This is untrue: The phenotype (i.e. structure and behavior) of an organism is a product of genotype AND environment. Two identical genotypes, exposed to different environments can result in different phenotypes e.g. http://www.nature.com/hdy/journal/vaop/ncurrent/full/hdy201492a.html

 

 

 

This is another point on which we probably aren't going to agree. There are a multitude of reasons for this lack of agreement. An individual is what it is. It comes into existence as an individual and its entire existence is dependent on its genes. But individuals learn and grow and they are affected by their perspective and experience. To a very great extent this learning is determined by its genes but some individuals are in unique circumstances or greatly affected by something they've experienced or learned. While most behavior of the moment is related to learning, the patterns of behavior and the way the animals learns are driven much more by genetics. All life is individual and individuals are the product of their genes but every individual has its own knowledge and experience. Stressors that cause population bottlenecks tend to select based on behavior but behavior is largely an expression of genetics.

 

It's variability in behavior (mostly nurture) that allows some individuals to survive bottlenecks. Some flies sometimes land on the underside of tables and this diversity of behavior leads to survival. But the genes of these oddballs is different enough that the offspring will be different. I've never observed any really strange structural or appearance difference but the new flies have been observed to be more lethargic than normal flies.

[iNow]

This is another point on which we probably aren't going to agree. There are a multitude of reasons for this lack of agreement. An individual is what it is. It comes into existence as an individual and its entire existence is dependent on its genes.

You can keep repeating yourself all you want, but repetition alone is not going to magically render this statement any less wrong.

Edited January 13, 2015 by iNow

[Ten oz]

@ cladking, what is it you believe? Rather than continuing to debate the definitions of words why not lay out a theory? From what I have gathered you are saying that evolutions as it is popularly understood could not have happened? You seem to believe in adaptation but not necessarily speciation? So how did life get here? Please be specific; if a guiding hand was used please explain whose hand and how. If DNA was made by an intelligent life form please explain how that intelligent life form made it. Then explain where that intelligent form came from and how it was made. Because if you can't provide those specifics your belief is far more vague than evolution is. It describes less and explains nothing.

[Arete]

This is another point on which we probably aren't going to agree.

 

So I think the discussion is at a fatal impasse. Trying to discuss evolution with someone who denies the existence of genotype-environment interactions is rather like trying to discuss gravity with someone who disagrees that objects are attracted to the earth.

[cladking]

@ cladking, what is it you believe? Rather than continuing to debate the definitions of words why not lay out a theory? From what I have gathered you are saying that evolutions as it is popularly understood could not have happened? You seem to believe in adaptation but not necessarily speciation? So how did life get here? Please be specific; if a guiding hand was used please explain whose hand and how. If DNA was made by an intelligent life form please explain how that intelligent life form made it. Then explain where that intelligent form came from and how it was made. Because if you can't provide those specifics your belief is far more vague than evolution is. It describes less and explains nothing.

 

Most of this is guesswork and is merely a coherent framework which fits visceral knowledge derived from observation and logic as well as scientific experimentation done by others. It is highly synopsized for brevity.

 

Life will arise anywhere the conditions exist that can support it but in almost every case it never has the chance to evolve from scratch because it is seeded extraterrestrially by life which has been spread throughout the galaxies in novas. This is the case on Earth as well. Every organism is an individual and every species occupies a niche. These niches tend to be stable in the short term for larger organisms but are not stable even in the short term for small organisms. Since species depend on their niche to survive even small changes can have very large effects. Small organisms tend to drive systems toward stability by having highly elastic populations.

 

The "over" complexity of genes caused by how ancient they are fascilitates their ability to manifest in nearly any way so that when a niche opens up a new species will arise (from an old one) to occupy it. Most change in species is the result of population bottlenecks which tend to select for behavior. Behavior is the complex interwokings of an individual and its enviroment and is never really understood. The individual is his genes and his enviroment is, for the main part, his experience and visceral knowledge (or beliefs in the case of humans). Since behavior is intimately entwined with genes when large percentages of a population dies due to some triviality of behavior the survivors have genes that are distinct in some way from the pre-bottleneck population. These genes then cause a difference in the offspring who are all far more likely to exhibit the behavior. They result in a change in the nature of the species that is encoded in the genes. When populations rebound the species will be distinct from the old one and not necessarily more "fit" on any parameter. However the old behavior is less common and if these individuals then breed back into a larger population the genes for that specific behavior will be more widespread and more likely to save the entire species from extinction. This is the source of both "diversity" and "evolution"; bottlenecks.

 

Of course "bottlenecks" have attributes and characteristics that make them ongoing even in stable populations. Each death is as individual as each life and "unfitness" and "improper behavior" are always being excluded from reproduction. In stable populations these cause change in species on glacially.

 

Modern science misses the big picture because it looks at tiny parts of the whole. It extrapolates the general from the specific and in this case the general is far too complicated for the tools of science.

 

So I think the discussion is at a fatal impasse. Trying to discuss evolution with someone who denies the existence of genotype-environment interactions is rather like trying to discuss gravity with someone who disagrees that objects are attracted to the earth.

 

How can I possibly determine why a specific rabbit that hangs around my door prefers one plant to another? Why will it hop right past one daisy to eat the next? Why does it come at a specific time rather than a few minutes later or earlier? I can't ask iut and if I could it wouldn't know either. It might tell you the rest of the family likes daffodils but this is hardly a means to start to identify the genes that cause the behavior.

 

Behavior is infinitely complex and genes are at its root.

 

Behavior exists not only in the realm of individual activity but storms are caused by butterflies in China.

 

When someone can predict the exact moment a cardinal lands on my feeder I'll believe we understand genes and behavior. In the meantime we are merely trying to explain the grossest aspects of nature and we can rarely predict these.

Edited January 13, 2015 by cladking

[Arete]

How can I possibly determine why a specific rabbit that hangs around my door prefers one plant to another? Why will it hop right past one daisy to eat the next? Why does it come at a specific time rather than a few minutes later or earlier? I can't ask iut and if I could it wouldn't know either. It might tell you the rest of the family likes daffodils but this is hardly a means to start to identify the genes that cause the behavior.

 

I really don't understand how any of these questions relate to the concept of genotype-environment interactions. The phenotype = genotype x environment concept is one of the oldest ideas in genetics (often characterized as nature vs nurture). It is simply that the physical characteristics of an organism is a result of both its heritable components, and the environmental conditions it is exposed to. This is an extremely fundamental idea in biology, which is generally taught in early high school and is supported by an inordinately gigantic body of observation evidence spanning centuries.

 

When you say you don't agree with it, it becomes difficult to have any sort of meaningful discourse about the topic, as is demonstrated by your non sequitur response.

Edited January 13, 2015 by Arete

[cladking]

 

I really don't understand how any of these questions relate to the concept of genotype-environment interactions. The phenotype = genotype x environment concept is one of the oldest ideas in genetics (often characterized as nature vs nurture). It is simply that the physical characteristics of an organism is a result of both its heritable components, and the environmental conditions it is exposed to. This is an extremely fundamental idea in biology, which is generally taught in early high school and is supported by an inordinately gigantic body of observation evidence spanning centuries.

 

When you say you don't agree with it, it becomes difficult to have any sort of meaningful discourse about the topic, as is demonstrated by your non sequitur response.

 

Back when I believed the cause of an individual and his behavior could be broken down into "nature vs nurture" I came down heavily on the side of nature. Now I believe it is a false dichotomy that doesn't even apply to humans but is irrelevant with non-human individuals. It only seems to apply to humans because we act on our beliefs so what we are taught is a primary component of our behavior. Animals act on their knowledge which is largely dependent on the means they acquire it which are usually related most closely to experience and genetics.

[Arete]

Now I believe it is a false dichotomy

 

That's the ENTIRE POINT of gene-environment interaction. It's not a dichotomy at all. The physical characteristics of an organism are a result of a COMBINATION of the ENVIRONMENT and GENES. I'm not sure it can be put more simply.

[swansont]

 

Most of this is guesswork and is merely a coherent framework which fits visceral knowledge derived from observation and logic as well as scientific experimentation done by others. It is highly synopsized for brevity.

 

Life will arise anywhere the conditions exist that can support it but in almost every case it never has the chance to evolve from scratch because it is seeded extraterrestrially by life which has been spread throughout the galaxies in novas. This is the case on Earth as well.

 

Unfortunately guesswork is almost of no value in science. We know of zero places elsewhere in the universe where life has arisen. There's no way to test this, and no scientific evidence to support it.

 

Probably all of nature's rules are probably exceedingly simple but they combine to make an impossibly complex reality. You can't simplify life to study it. You can breed it or change it but there's no more such a thing as an "average" bacterium than there is an "average" hydrogen atom. Just as no hydrogen atom is more "fit" than another, no rabbit is more "fit" than another. It's mere hubris that says we can legitimately call survivors "fit". When hydogen burns every atom doesn't have an equal probability of combining with oxygen. It depends on the oxygen atom and the precise orientations and trajectories and God knows what else. Any hydrogen atoms left over are not more fit than those which were consumed (combined).

 

Reality is infinitely complex. Our knowledge is derived from simple experiment.

 

To the extent that hydrogen atoms are identical, this is simply a bad example — there's no "fitness" difference for identical individuals. But it turns out the hydrogen atoms (and other atoms) aren't identical — there are isotopes. And gee whiz, what we find out is that chemical reactions happen at different rates for different isotopes. So if you had some fraction of your hydrogen is actually H-2, after the combustion reaction you would find that the leftovers had a different fraction of the makeup than you started with (and the fraction of heavy water would differ in the other direction, because math). Your contention is simply flat-out wrong.

 

So even though you can't tell for an individual atom what's going to happen, with a large number you can tell statistically what's going to happen. Just as with the field of thermodynamics and radioactive decay — we can tell with good precision what will happen to a large number of particles. Since that's what we know, that's what we model. No point in trying to predict something you can't model, or for which you will never have enough data. Your contention that you need to be able to tell what happens to an individual is just patently false, and an artificial constraint you are arbitrarily placing on the problem.

[cladking]

 

That's the ENTIRE POINT of gene-environment interaction. It's not a dichotomy at all. The physical characteristics of an organism are a result of a COMBINATION of the ENVIRONMENT and GENES. I'm not sure it can be put more simply.

 

Is this really the state of the art in biology?!

 

How can enviroment shape the alveoli in utero? Certainly if some abnormality or disease exists it's possible that such structure can be affected but these things are simply defined genetically and enviroment has virtually no role whatsoever. Indeed, thios same should apply very much to all human structure though more subtle structure like the map of the eye might be more dependent on enviroment. Even after birth the growth of the organism and the order and resultant patterns are defined primarily genetically. In humans this will break down after the acquisition of language but providing the individual has proper nutrition most of the development is set at conception.

 

In other individual animals and life forms divergence of behavior from genetic causations will break down with experience and learning. The rabbit predisposed to eat daisies might skip those growing in direct sunlight because of previous experience. In the "adult" most behavior is primarily the result of experience and knowledge. Individual structure and genetics still play a primary and pivotal role in aging and preferences but moment to moment behavior approaches being strictly based on visceral knowledge.

 

But the key point here is that genetics are central to even behavior and genetics are expressed as higher probabilities of specific behavior. A rabbit predisposed to eat daisies at conception is far more likely to be found in a field of daisies than its brother predisposed to daffodils. This won't change throughout their lifetimes. When something comes along to selectively kill rabbiyts that eat daffodils one rabbit has a high probility of dying and the other a high probility of surviving. There simply is nothing to do with being "fit" or more suited to the enviroment. Daisy eaters survive prefentially to others. The genes which express as a preference to daisies are highly complex and affect much more of the animal than simply which food it prefers. They might affect anything from shape of the nose to the chemistry which digests food. It might affect the size of the tail or the speed the animal hops.

 

"Fit" simply means nothing to nature. It means nothing to God. And it means nothing to the probilities of survival. It is simply a concept that people observe when they see a "rabbit" get eaten. Obviously to all observers if the rabbit had been faster it wouldn't have been caught so we imagine it's less fit than the one that got away. But the reality is simply the cheetah was hunting in the daffodils rather than the daisies. It might have survived if it had been faster or more alert but rabbits are rabbits. All individual rabbits are genetically rabbits and they each are vigilant and fast. Daisy eaters are probably no faster than their brothers but if only the daisy eaters survive a near extinction than their off spring might be much faster or much slower than "rabbits". Species change and they change because they are selected for behavior just as man tames the animals.

 

Genes define behavior and behavior defines survival.

 

Nature defines nurture and nurture defines nature.

 

Unfortunately guesswork is almost of no value in science. We know of zero places elsewhere in the universe where life has arisen. There's no way to test this, and no scientific evidence to support it.

 

To the extent that hydrogen atoms are identical, this is simply a bad example — there's no "fitness" difference for identical individuals. But it turns out the hydrogen atoms (and other atoms) aren't identical — there are isotopes. And gee whiz, what we find out is that chemical reactions happen at different rates for different isotopes. So if you had some fraction of your hydrogen is actually H-2, after the combustion reaction you would find that the leftovers had a different fraction of the makeup than you started with (and the fraction of heavy water would differ in the other direction, because math). Your contention is simply flat-out wrong.

 

So even though you can't tell for an individual atom what's going to happen, with a large number you can tell statistically what's going to happen. Just as with the field of thermodynamics and radioactive decay — we can tell with good precision what will happen to a large number of particles. Since that's what we know, that's what we model. No point in trying to predict something you can't model, or for which you will never have enough data. Your contention that you need to be able to tell what happens to an individual is just patently false, and an artificial constraint you are arbitrarily placing on the problem.

 

I'm a little surprised you would dismiss the contention that no two atoms are identical while we know so little about the individual atoms. Of course the math works out in chemical reactiuons since with such an enormous sample of atoms there will be an "average" and the differences bewtween atoms is necesaarily small from our perspective. We can't really separate atoms by any parameter at the current time but then we don't understand the electromagnetic, strong, weak, and gravitational forces and their interactions and natures. Under these conditions and considering the small size of atoms and their potential differences how are we to separate or study individiual atoms? Whose to say that if you have ten too many atoms of an element in aa chemical reaction that every single atom has the exact same probability of being combined as every other atom to an infinity of decimal points. Logically this is impossible because no two things in nature which we can observe are identical. Why would atoms and quarks all be identical?

 

"Guesses" are part of scientific metaphysics. They go by many names from logic to hypothesis, and from intuition to studied experimental results. More than anything it is guesses that lifted man from the caves and is preventing his return. Guesses in the absense of logic, observation, and/ or experiment mean nothing.

Here's a little tidbit that I find interesting.

 

http://www.rawstory.com/rs/2015/01/junk-dna-from-million-year-old-viruses-actually-have-vital-role-in-human-intelligence-study/

 

This is exactly the kind of thing that shows how supremely complicated nature really is. Chemistry and physics are mere child's play compared to genetics and its interplay with behavior.

 

Math is a quantified logic that works well to understand experiment and theory but it has no bearing on nature. Things derived from math appear to be true and theory is true but nature is not responsible to make math work. It is the way of nature only because it follows logic and uses numbers as a self check for logic. You can not simply count rabbits or hydrogen atoms and learn their natures.

Edited January 14, 2015 by cladking

[Arete]

Is this really the state of the art in biology?!

 

No, this would be middle school level biology. I'm a little flabbergasted that you're finding it so hard to accept such a basic, simple concept in biology. I would really suggest doing a little reading, as you seem to have a lot of incorrect ideas about biology in general. I think it would be of great benefit to your understanding to do some basic research . At the moment it does seem like you're not even reading the provided links in previous posts, given the repletion of incorrect assertions, which makes it difficult for any progression of the discussion.

 

 

How can enviroment shape the alveoli in utero?

 

"Environmental factors prevailing during early life that have been linked to long-term changes in lung structure, lung function and respiratory health include undernutrition, preterm birth, reduced intrathoracic space, respiratory infections, maternal tobacco smoking and exposure to allergens." https://www.karger.com/ProdukteDB/Katalogteile/isbn3_8055/_91/_39/Early-life_03.pdf

 

 

 

Indeed, thios same should apply very much to all human structure

 

 

Here is a list of known developmental teratogens http://www.purdue.edu/ehps/rem/ih/terat.htm. A myriad of environmental exposures can influence fetal development.

 

 

In other individual animals and life forms divergence of behavior from genetic causations will break down with experience and learning. ... In the "adult" most behavior is primarily the result of experience and knowledge ... Individual structure and genetics still play a primary and pivotal role in aging and preferences but moment to moment behavior approaches being strictly based on visceral knowledge ...But the key point here is that genetics are central to even behavior and genetics are expressed as higher probabilities of specific behavior ...This won't change throughout their lifetimes ... The genes which express as a preference to daisies are highly complex and affect much more of the animal than simply which food it prefers.

 

Could you please provide a citation for these statements... many of them are inherently flawed or outright incorrect.

 

 

"Fit" simply means nothing to nature. It means nothing to God. And it means nothing to the probilities of survival.

 

 

This might be so when, as you have done, choose to define fitness as something different from the definition of the term in science. But then I could choose to define a potato as a airplane and tell everyone else that they are wrong about french fries. It wouldn't make very much sense though.

 

I think most of what you are displaying is a fundamental lack of understanding about fundamental biology. I again would strongly suggest catching up on some basics, as the current discussion is rather fruitless.