The Selfish Gene Theory

[Mitch Bass]

The problem I have with genetic theories of evolution is that although genes are the templates of life, how does the template alter the template? For example, the template of all molecules is connected to atomic orbitals and atoms.

 

You've made a simple process far to complex. Genetic mutations arise either because of environmental insult (radiation, carcinogens, etc) or a copying error.

Coneptual is having a problem with the genetic theories of evloution. Mokele is atttempting to solve this problem by bringing up the phenomenon of genetic mutation. I have carefully studied the words in two books that Richard Dawkins produced. The first is THE SELFISH GENE and the seond is the EXTENDED PHENOTYPE. Somewhere within these two books the genetic theory of evolution that Conceptual is having a problem with is not entirely explained by what the mutation effect that Mokele described. In fact only a small portion of evolution is considered by Dawkins to be s product of mutation. When DNA creates a body the body it creates is known as an "extended phenotype". Every animal that exist is born the way it is born because of of the "instructions" that the DNA has in terms of how the animal will be constructed. The DNA that is giving out these instructions is a resullt almost always of the contribution of two parents. Evolution is very little about the creation of animals that evolve because of DNA mutuation but rather the success or failure of the combination of DNA contributions from two different animals that create offspring that will be different than themselves. If the combination of DNA creates an offspring that does well than some of those genes from that animal will be passed on to any children of the animal.

 

Dawkins uses the metaphor of a rowing team when considering the governing dynamic behind the force of evolution. Dawkins writes about how a rowing team consists of for a number of memebers. Depending on the total effect of all the members, the rowing team will win or lose.

 

I forget how far Dakwins went with this metaphor, but I will extend it so that evolution makes sense without having to consider the mutation of DNA as the fundamental force.

 

So imagine if each rowing team was an individual animal and the memebers of the rowing team were genes. The members of each rowing team, the genes of each animal, have come from taking memebers from two different prior rowing teams that created a group of members that made it at least to the point where they could pass on their genetic material. Each gene influences some part of how an animal will be constructed. The new combinations of genes as a result of there being two genetic contributors is what makes for an animal to be different than the two animals that contributed to the birth of the animal.

[Ophiolite]

 

While Darwin was not the only one to come up with the idea of Natural Selection, his idea of common ancestry was very unique and significant.

Two points:

1. Common ancestry was, at the very least, implicit in Wallace's thinking. Are you asserting that it was not?

2. Please don't qualify an absolute! Things are either unique, or they are not. Very unique is like slightly pregnant, an impossible condition.

[StringJunky]

2. Please don't qualify an absolute! Things are either unique, or they are not. Very unique is like slightly pregnant, an impossible condition.

Pedant. He was just being emphatic..

[Ophiolite]

Pedant. He was just being emphatic..

I'd rather be a pedant than a peasant.

[StringJunky]

I'd rather be a pedant than a peasant.

[chadn737]

Two points:

1. Common ancestry was, at the very least, implicit in Wallace's thinking. Are you asserting that it was not?

2. Please don't qualify an absolute! Things are either unique, or they are not. Very unique is like slightly pregnant, an impossible condition.

 

1) Darwin was explicit about universal common descent. The only figure/illustration in the Origin is one of the very first phylogenetic trees ever drawn. While Wallace's theory of natural selection would obviously have assumed some limited common ancestry...after all, there is no such thing as evolution without common ancestry...the idea of "universal common descent" to my knowledge is not. If you think otherwise, then please point me to the works where Wallace spells out this concept of universal common descent. The two theories of Natural Selection also differed in subtle, yet profound ways. Some have even argued that Wallace's origin concept was more one of group selection rather than individual selection.

 

2) It is very unique.

 

Coneptual is having a problem with the genetic theories of evloution. Mokele is atttempting to solve this problem by bringing up the phenomenon of genetic mutation. I have carefully studied the words in two books that Richard Dawkins produced. The first is THE SELFISH GENE and the seond is the EXTENDED PHENOTYPE. Somewhere within these two books the genetic theory of evolution that Conceptual is having a problem with is not entirely explained by what the mutation effect that Mokele described. In fact only a small portion of evolution is considered by Dawkins to be s product of mutation. When DNA creates a body the body it creates is known as an "extended phenotype". Every animal that exist is born the way it is born because of of the "instructions" that the DNA has in terms of how the animal will be constructed. The DNA that is giving out these instructions is a resullt almost always of the contribution of two parents. Evolution is very little about the creation of animals that evolve because of DNA mutuation but rather the success or failure of the combination of DNA contributions from two different animals that create offspring that will be different than themselves. If the combination of DNA creates an offspring that does well than some of those genes from that animal will be passed on to any children of the animal.

 

Dawkins uses the metaphor of a rowing team when considering the governing dynamic behind the force of evolution. Dawkins writes about how a rowing team consists of for a number of memebers. Depending on the total effect of all the members, the rowing team will win or lose.

 

I forget how far Dakwins went with this metaphor, but I will extend it so that evolution makes sense without having to consider the mutation of DNA as the fundamental force.

 

So imagine if each rowing team was an individual animal and the memebers of the rowing team were genes. The members of each rowing team, the genes of each animal, have come from taking memebers from two different prior rowing teams that created a group of members that made it at least to the point where they could pass on their genetic material. Each gene influences some part of how an animal will be constructed. The new combinations of genes as a result of there being two genetic contributors is what makes for an animal to be different than the two animals that contributed to the birth of the animal.

 

New genes and new variants arise through mutation. Without mutation there is no variation to recombine into better combinations.

 

While most of evolution in sexually reproducing organisms will operate upon standing variation over the short term, over the length of evolutionary history, mutation is the source of that variation.

[Ophiolite]

 

1) Darwin was explicit about universal common descent. The only figure/illustration in the Origin is one of the very first phylogenetic trees ever drawn. While Wallace's theory of natural selection would obviously have assumed some limited common ancestry...after all, there is no such thing as evolution without common ancestry...the idea of "universal common descent" to my knowledge is not. If you think otherwise, then please point me to the works where Wallace spells out this concept of universal common descent.

I explicitly said that the requirement for universal common descent is implicit in Wallace's theory. I did not say it was explicit. Given that it was implicit that means Darwin's contribution was, therefore, not unique.

 

In this extract from his 1858 paper (emphasis mine) the requirement for common descent is clear. I can agree that Wallace may not have recognised the import of what he was saying, but it is inherent (pun intended) in what he wrote.

 

An origin such as is here advocated will also agree with the peculiar character of the modifications of form and structure which obtain in organized beings--the many lines of divergence from a central type, the increasing efficiency and power of a particular organ through a succession of allied species, and the remarkable persistence of unimportant parts such as colour, texture of plumage and hair, form of horns or crests, through a series of species differing considerably in more essential characters.

 

Finally, you are - I suppose - free to write incorrect English if you wish, but it is distracting.

[chadn737]

I explicitly said that the requirement for universal common descent is implicit in Wallace's theory. I did not say it was explicit. Given that it was implicit that means Darwin's contribution was, therefore, not unique.

 

In this extract from his 1858 paper (emphasis mine) the requirement for common descent is clear. I can agree that Wallace may not have recognised the import of what he was saying, but it is inherent (pun intended) in what he wrote.

 

An origin such as is here advocated will also agree with the peculiar character of the modifications of form and structure which obtain in organized beings--the many lines of divergence from a central type, the increasing efficiency and power of a particular organ through a succession of allied species, and the remarkable persistence of unimportant parts such as colour, texture of plumage and hair, form of horns or crests, through a series of species differing considerably in more essential characters.

 

Finally, you are - I suppose - free to write incorrect English if you wish, but it is distracting.

 

I know you said "implicit". I made the point of emphasizing how "explicit" Darwin was because Darwin realized how ground shaking universal common descent was. And having read Wallace's 1858 essay as well, I am not convinced that this one line shows that the concept of universal common descent was implicit. In my last post I stated that common ancestry is a given in evolution, but that does not mean that there is a universal common ancestor implicit in the idea of evolution. There are many creationist/intelligent design advocates who argue for limited speciation within certain lineages and against universal common descent. It is impossible to tell from his 1858 essay whether or not Wallace was implying descent in this fashion or of the grander universal common descent that Darwin advocated. I do not mean to lessen Wallace's contributions, but there are reasons why we give more credit to the likes of Darwin, and this is a major reason.

 

And I am free to write as I wish and qualifying an absolute really is not distracting. Nitpicking of English at this level is really about trying to score points.

Edited May 27, 2014 by chadn737

[Mitch Bass]

 

1) Darwin was explicit about universal common descent. The only figure/illustration in the Origin is one of the very first phylogenetic trees ever drawn. While Wallace's theory of natural selection would obviously have assumed some limited common ancestry...after all, there is no such thing as evolution without common ancestry...the idea of "universal common descent" to my knowledge is not. If you think otherwise, then please point me to the works where Wallace spells out this concept of universal common descent. The two theories of Natural Selection also differed in subtle, yet profound ways. Some have even argued that Wallace's origin concept was more one of group selection rather than individual selection.

 

2) It is very unique.

 

New genes and new variants arise through mutation. Without mutation there is no variation to recombine into better combinations.

 

While most of evolution in sexually reproducing organisms will operate upon standing variation over the short term, over the length of evolutionary history, mutation is the source of that variation.

 

First I will respond to the second part of this quote. Perhaps you are not fully aware of the process of evoltion at the genetic level and how almost trival mutation is to evolution. I started a new post about this subject. I wanted to make a common misperception that you wrote become clear and evident in term of the reality of the situation in terms of the extent of mutations force on evolution. I wll do this right now in a clean, cut metaphor that should help you to appreciate what I am saying, The metaphor is in response to your words which are" New genes and new variants arise through mutation. Without mutation there is no variation to recombine into better combinations." Think in terms of the 26 letters of the alphabet. Letter do not mutate yet will this prevent the short or long range potential to to recomine the in ways whichg can become a better story, a more interesting phiosophy a better book to explain the univerese in better ways than it has been in the past. ?

[chadn737]

 

First I will respond to the second part of this quote. Perhaps you are not fully aware of the process of evoltion at the genetic level and how almost trival mutation is to evolution. I started a new post about this subject. I wanted to make a common misperception that you wrote become clear and evident in term of the reality of the situation in terms of the extent of mutations force on evolution. I wll do this right now in a clean, cut metaphor that should help you to appreciate what I am saying, The metaphor is in response to your words which are" New genes and new variants arise through mutation. Without mutation there is no variation to recombine into better combinations." Think in terms of the 26 letters of the alphabet. Letter do not mutate yet will this prevent the short or long range potential to to recomine the in ways whichg can become a better story, a more interesting phiosophy a better book to explain the univerese in better ways than it has been in the past. ?

 

I don't think you really understand how recombination works. Recombination acts to move shuffle around the standing variation within a population, but it does not produce that variation to begin with...unless of course there is an error during recombination, also known as a "mutation."

 

Without that standing variation, recombination will not produce any new combinations of alleles. Consider an inbred line. Many plant species self-pollinate, leading to inbred accessions that are almost genetically homogenous. Recombination still goes on during meiosis, but since their is limited genetic variation, that recombination does not produce new combinations. In the absence of genetic variation, recombination have limited effect.

 

So where does the genetic variation that recombination works with come from? Unless you believe that populations of species simply popped into existence out of nothing with the full-breadth of genetic variation found in that population, then there must be some other source of said genetic variation. The source of that genetic variation is mutation.

 

If you look at evolution over the span of only a few generations, yes, recombination is going to play a bigger role. The reason for that is that the population you are studying already has standing genetic variation (thanks to previous mutations) and the mutation rates are probably low enough that over the span of only a few generations, not much new variation is going to arise. However, over the course of many generations and over the course of evolutionary time, the ultimate source of all variation is mutation.

 

Start with the 26 letters and only "26" letters....meaning you have only 26 letters that can be used once. How much do you think you can actually write? A single word like "hello" cannot be written with just the 26 letters because there are two "L"s in hello and you only have one "L" in your 26 letters. In order to write "hello", you need to somehow duplicate the letter "L". A duplication like that is a mutation. Now with two "L"s its possible for recombination to not only write "hello", but also "mellow", and "yellow". Without that mutation producing a second "L" recombination will never write any of those words or any word that requires two "L"s.

Edited May 27, 2014 by chadn737

[Hyena]

First, I want to acknowledge that this is an interesting and important thread. Props, OP. I understand that this is a 9-yr old thread.

 

This caught my attention:

 

The problem I have with genetic theories of evolution is that although genes are the templates of life, how does the template alter the template?

 

I have a bit of an... obsession with feedback loops. Your observation piques my interest, and I, lately, have been tinkering with my own ideas as to how one could explain something like this.

 

I'm assuming that by 'template alter the template', you mean that DNA (or whatever means of propagating genetic information) alters itself in a way that allows for further success (read: continued "existence" of that biological molecule).

 

If I understand correctly, your question is asking how DNA can react to itself, in a way. How can DNA continue to make changes to itself over the course of time to continue to be successful, biologically speaking? This is a bona-fide positive feedback loop.

 

To answer your question, I must first preface that it is not a simple answer. In fact, it is not an answer at all, but just a couple ideas I've strung together that could help to shed some light on the issue. The first idea to consider is that of 'Ecolgical Perception', or in philosophy, as it is called, Direct Perception. It is the idea that organisms react solely to the information given to them by their environment. Action is preceded by interpretation - cause and effect, if you will - and thus whatever the agent can identify/percieve, it can act accordingly. What use does this have when considering your question?

 

From one of my writings:

"If it is the case that an organism is substantiated through the results of its own actions, and therefore its actions in reponse thereafter, then there exists some positive feedback loop in which the responses to the effects of said organism's actions interact with its previous responses. That is to say, how an organism responds to its environment is in some way intrinsically tied to how it responded before."

 

This is from a line of thought dealt with a little more in depth here, where I consider a term I've coined an invasive loop if you will, or a sel-fulfilling prophecy: autopropagation (initially developed through consideration of a universal set of traits inherent in invasive species). The idea is that a successful species capitalizes on the impacts it has made in the environment. As the most observable instance, zebra mussels (or any other ecosystem engineer) literally use themselves as the substrate, using their ability to reproduce quickly and efficiently to their advantage by living rooting themselves to each other. Who better than to utilize self-created niche space than the creator? (population-wise in this instance). The philosophical equivalent is Reciprocal Determinism.

 

So, what does this mean in accordance to 'template altering template', as you've asked?

 

Doesn't the genetic makeup of an organism determine its life history, and in some way its ability to percieve and react to the environment? The ability of zebra mussels to use each other as a substrate is certainly not present in all organisms, and as such, that particular trait is not present in all living things. However, the concept, I argue, is; the ability to capitalize on the changes that organism has made.

 

"In effect, the actions of an organism are determined by the interactions between responses, which are determined by the genetic code; over time, when a population can evolve via natural selection, portions of DNA in that population's genetic background code for the most successful outcomes of these interactions, and thus, the DNA itself is actually indirectly selecting for other portions of DNA through positive feedback loops between organismal behavior and coded responses to implications of that behavior, ie. reciprocal responses"

 

From a link in the OP:

"Selfish Gene Theory regards the visible organism (the cat, human, flower, amoeba or whatever) as the host"

 

What better way to ensure (or at least give a better chance of) continuation of genetic code by capitilazing on the changes your 'host' has made in the environment?

 

Not to say that it is a conscious effort of DNA to replicate and choose to do such a thing, but if it is indeed a successful (assuming it actually exists) blueprint, then its place in evolution wouldn't be surprising.

 

-Hyena

[chadn737]

First, I want to acknowledge that this is an interesting and important thread. Props, OP. I understand that this is a 9-yr old thread.

 

This caught my attention:

 

 

I have a bit of an... obsession with feedback loops. Your observation piques my interest, and I, lately, have been tinkering with my own ideas as to how one could explain something like this.

 

I'm assuming that by 'template alter the template', you mean that DNA (or whatever means of propagating genetic information) alters itself in a way that allows for further success (read: continued "existence" of that biological molecule).

 

If I understand correctly, your question is asking how DNA can react to itself, in a way. How can DNA continue to make changes to itself over the course of time to continue to be successful, biologically speaking? This is a bona-fide positive feedback loop.

 

To answer your question, I must first preface that it is not a simple answer. In fact, it is not an answer at all, but just a couple ideas I've strung together that could help to shed some light on the issue. The first idea to consider is that of 'Ecolgical Perception', or in philosophy, as it is called, Direct Perception. It is the idea that organisms react solely to the information given to them by their environment. Action is preceded by interpretation - cause and effect, if you will - and thus whatever the agent can identify/percieve, it can act accordingly. What use does this have when considering your question?

 

From one of my writings:

"If it is the case that an organism is substantiated through the results of its own actions, and therefore its actions in reponse thereafter, then there exists some positive feedback loop in which the responses to the effects of said organism's actions interact with its previous responses. That is to say, how an organism responds to its environment is in some way intrinsically tied to how it responded before."

 

This is from a line of thought dealt with a little more in depth here, where I consider a term I've coined an invasive loop if you will, or a sel-fulfilling prophecy: autopropagation (initially developed through consideration of a universal set of traits inherent in invasive species). The idea is that a successful species capitalizes on the impacts it has made in the environment. As the most observable instance, zebra mussels (or any other ecosystem engineer) literally use themselves as the substrate, using their ability to reproduce quickly and efficiently to their advantage by living rooting themselves to each other. Who better than to utilize self-created niche space than the creator? (population-wise in this instance). The philosophical equivalent is Reciprocal Determinism.

 

So, what does this mean in accordance to 'template altering template', as you've asked?

 

Doesn't the genetic makeup of an organism determine its life history, and in some way its ability to percieve and react to the environment? The ability of zebra mussels to use each other as a substrate is certainly not present in all organisms, and as such, that particular trait is not present in all living things. However, the concept, I argue, is; the ability to capitalize on the changes that organism has made.

 

"In effect, the actions of an organism are determined by the interactions between responses, which are determined by the genetic code; over time, when a population can evolve via natural selection, portions of DNA in that population's genetic background code for the most successful outcomes of these interactions, and thus, the DNA itself is actually indirectly selecting for other portions of DNA through positive feedback loops between organismal behavior and coded responses to implications of that behavior, ie. reciprocal responses"

 

From a link in the OP:

"Selfish Gene Theory regards the visible organism (the cat, human, flower, amoeba or whatever) as the host"

 

What better way to ensure (or at least give a better chance of) continuation of genetic code by capitilazing on the changes your 'host' has made in the environment?

 

Not to say that it is a conscious effort of DNA to replicate and choose to do such a thing, but if it is indeed a successful (assuming it actually exists) blueprint, then its place in evolution wouldn't be surprising.

 

-Hyena

 

I find this confusing.

 

Either you are simply reiterating the concept of Natural Selection on the genome or you are proposing that DNA is directing selection on itself in some fashion.

[Ophiolite]

 

I find this confusing.

 

Either you are simply reiterating the concept of Natural Selection on the genome or you are proposing that DNA is directing selection on itself in some fashion.

My thoughts exactly. Once one removes the verbosity all Hyena seems to be saying is that organisms that make particular "choices" because of their genetic predisposition to do so will flourish, relatively, if those choices are 'good' ones. Hyena, if you are saying something else could you try to say it more directly and simply.

[Hyena]

 

I find this confusing.

 

Either you are simply reiterating the concept of Natural Selection on the genome or you are proposing that DNA is directing selection on itself in some fashion.

It's both. I apologize for the confusion - I often feel the need to be more specific when trying to explain concepts that to me are difficult to understand. I'm proposing that DNA directs selection on itself through the processes of Natural Selection, using the 'host' as its vector of sorts.

 

On a side note, I'm not so used to communicating these ideas to people who actually have a good grasp on the concept of evolution and Natural Selection, so I beg your pardon with my mostly unneccesary reiteration.

 

My thoughts exactly. Once one removes the verbosity all Hyena seems to be saying is that organisms that make particular "choices" because of their genetic predisposition to do so will flourish, relatively, if those choices are 'good' ones. Hyena, if you are saying something else could you try to say it more directly and simply.

I'm simply trying to continue on the 'template altering template' idea posted before me. The idea that the genome indirectly alters itself through the actions of the organism.

 

I'm playing with two ideas here: one is that the organism isn't much more as a walking sack of DNA, ultimately subject to what's written in its genetic code, and secondly that the genetic code, through Natural Selection, alters itself. It's quite the same as what one would observe in your typical case of natural selection, but there is one more layer of complexity involved. Rather than, let's say, a species evolving over time due to uncontrollable agents in its environment, that species evolves due to controllable agents in its environment, ie the changes that it has made.

 

Thus I incorporated the whole ecosystem engineer idea, because it's the most plain to see. Those organisms obviously alter their environment in easily observable physical ways. Of course the most successful species (and in turn, the most successful 'strain' of genes) will capitalize on these changes.

 

I apologize for my point being lost in my verbosity (as unfortunately is often the case), but the main point I was trying to configure is that there exists a positive feedback loop between organisms and their interactions with the environment, and that this feedback loop is subject to change via Natural Selection; in essence, organisms are increasing the pressure of Natural Selection on themselves. I fear that the misunderstandings have arisen when I continued on this path, talking about how the DNA is the root of these interactions with the environment. For this I apologize.

 

I hope this clears a few things up. Please feel free to continue to ask question, or PM me (if that's a thing here).

 

-Hyena

Edited June 9, 2014 by Hyena

[chadn737]

A little bit of both. I apologize for the confusion - I often feel the need to be more specific when trying to explain concepts that to me are difficult to understand. I'm proposing that DNA directs selection on itself through the processes of Natural Selection, using the 'host' as its vector of sorts.

 

Most of the genome of a typical organism is not under selection, but evolving neutrally. Dependent upon factors such as genetic hitchhiking and genetic drift, deleterious alleles can actually increase in frequency. This says that DNA does not direct selection on itself.

[Ophiolite]

I'm playing with two ideas here: one is that the organism isn't much more as a walking sack of DNA, ultimately subject to what's written in its genetic code, and secondly that the genetic code, through Natural Selection, alters itself.

This is Lamarkian! The genetic code can only change through a mutation. You are suggesting, if have understood you, that the changes to the genetic code will be those changes that are most suitable for that environment. This does not happen. Do you have evidence to support such a mechanism?

 

(And thank you for your detailed reply.)

Edited June 9, 2014 by Ophiolite

[Hyena]

 

Most of the genome of a typical organism is not under selection, but evolving neutrally. Dependent upon factors such as genetic hitchhiking and genetic drift, deleterious alleles can actually increase in frequency. This says that DNA does not direct selection on itself.

I understand that most of the genome evolves neutrally. What is it, +90% of all mutations result in neutral or deleterious changes? I am not arguing that. But, consider, chad, that despite this fact you have just presented, evolution still occurs. Phenotypic change can only be the result of a change in the genetic code, which is, as we all know, either the result of mutations, epigenetic impacts, or viral incorporation (as far as novel genetic material is concerned), or the result of natural selection (as far as 're-assortment' of pre-existing DNA is concerned ie. no new genetic material).

 

Natural selection is the driver of evolution, yet it rarely directly impacts the genetic code, as far as changing what is written, so to speak. Yet how is it that a hummingbird's beak fits perfectly into the flower to get nectar and pollinate the plant? Yes, the genetic material responsible for coding for these specific phenotypes was the result of (most likely) neutral evolution, but the fine-tuning, so to speak, is the result of natural selection; birds with sleeker beaks could get more nectar, and in turn, those birds had more offspring. The chain continues, as specific DNA is selected for by the environmen ie the plant that the bird feeds on.

 

So, consider a situation where the organism actually manipulates its own environment. All organisms do it; otherwise there would be no interactions, they could not eat, drink, build a nest, etc. Would not natural selection also impact these interactions, the same interactions that were originated by the organism, and traceable back to that organism's genetic code? In response to the next question I will delve more deeply into specific situations, but consider these points:

 

-All organisms interact with their environment

-Behaviour (interactions) is due to chemical, physiological, mechanical constraints

-Constraints are induced by availability of genetic material (ie an organism's genetic makeup determines what it can and cannot do)

-Environment, through natural selection, drives evolution

-Interactions between organisms and environement drive environmental change

 

We see a loop where organisms interact with their environment, and the environment selects for individuals with the highest reproductive success. Therefore, organisms will be the most successful if they can manipulate the environmen to give them the highest total reproductive success. These manipulations are due to the genetic code. So, it follows that DNA is using its 'host' as a proxy to select for the most reproductively successful individuals, to continue passing on the DNA.

 

In short, the point that new genetic material is the result of random mutations is moot.

 

This is Lamarkian! The genetic code can only change through a mutation. You are suggesting, if have understood you, that the changes to the genetic code will be those changes that are most suitable for that environment. This does not happen. Do you have evidence to support such a mechanism?

 

(And thank you for your detailed reply.)

It is not Lamarkian.

 

It is simply Natural Selection.

 

Individuals with the highest propensity to pass on their genes survive, and their offspring will thus have a better chance to pass off their genes. It is assumed that these individuals have some advantage (ie reproductive success) over their competitors, otherwise it would be a case of neutral evolution, or genetic drift, or something of that sort. If the attributes responsible for increasing reproductive success are ones that capitalize on sellf-inflicted changes in the environment, then it follows that the genes that code for the behaviour that modifies the environment in such a way are effectively altering natural selection to continue to select for the reproduction of individuals with those genes (both ones that incite initial modificational behaviour and ones that capitalize on the results of that behaviour).

 

Lamarck posited more of an epigenetic approach (which is, as we continue to understand more and more, accurate in some instances), whereby organisms changed during their lifetime and passed on those changes to their offspring. I am suggesting no such thing.

 

I'm enjoying this thoroughly. Please continue to question!

 

-Hyena

 

Edit: Ah! Evidence! I've not the time at this exact moment. I have... obligations. But, in my next post, (or if I can edit this one still when I have time again) I will provide you with ample evidence, hopefully.

Edited June 9, 2014 by Hyena

[Ophiolite]

OK, since you were not describing a Lamarkian process - though you certainly appeared to be - I can see absolutely no difference between what you are describing and standard Darwinian theory. You seem to feel you have introduced something novel: will you take another attempt at defining, succinctly what is different about your hypothesis?

[Hyena]

OK, since you were not describing a Lamarkian process - though you certainly appeared to be - I can see absolutely no difference between what you are describing and standard Darwinian theory. You seem to feel you have introduced something novel: will you take another attempt at defining, succinctly what is different about your hypothesis?

I think the difference between my hypothesis and standard Darwinian theory is the incorporation of a self-perpetuated selection loop. That probably makes no sense.

 

What I am trying to describe is the relationship between the agent (in this case, any organism) and its manipulation of the environment; a loop exists between agent and interactions with the environment. The organism changes the environment in a way that creates a more optimal environment for its causes* (reproductive success) and in turn, alters the way that natural selection drives evolution for that species (and others in the same environment, as well).

 

Really, the only difference between my hypothesis and Darwin's is that I'm considering the changes that any organism may implement on its surroundings, which in turn alter Natural Selection over a longer period of time. The result is that species evolve to be suited for their habitat not only through random genetic mutations selected for by the environment (and certainly not through changes in that specific organism in its own lifetime, as you think I've been suggesting), but also indirectly through the changes that organism incurs to the environment (because the environment, Natural Selection, drives evolution).

 

It is not so much a novel hypothesis(?) as it is a proposed consequence of Natural Selection combined with agent-based environmental change. Since all organisms alter their environment in some way, I think that this consequence, if it holds true, is important when considering the evolutionary history of all organisms.

 

*An important caveat is that changes made to the environment are not necessarily beneficial to the organism. However, it still holds that these changes direct the 'direction' of Natural Selection (with the understanding that Natural Selection is in fact directionless, but for lack of a better word).

 

-Hyena

Edited June 10, 2014 by Hyena

[chadn737]

I understand that most of the genome evolves neutrally. What is it, +90% of all mutations result in neutral or deleterious changes? I am not arguing that. But, consider, chad, that despite this fact you have just presented, evolution still occurs. Phenotypic change can only be the result of a change in the genetic code, which is, as we all know, either the result of mutations, epigenetic impacts, or viral incorporation (as far as novel genetic material is concerned), or the result of natural selection (as far as 're-assortment' of pre-existing DNA is concerned ie. no new genetic material).

 

Natural selection is the driver of evolution, yet it rarely directly impacts the genetic code, as far as changing what is written, so to speak. Yet how is it that a hummingbird's beak fits perfectly into the flower to get nectar and pollinate the plant? Yes, the genetic material responsible for coding for these specific phenotypes was the result of (most likely) neutral evolution, but the fine-tuning, so to speak, is the result of natural selection; birds with sleeker beaks could get more nectar, and in turn, those birds had more offspring. The chain continues, as specific DNA is selected for by the environmen ie the plant that the bird feeds on.

 

So, consider a situation where the organism actually manipulates its own environment. All organisms do it; otherwise there would be no interactions, they could not eat, drink, build a nest, etc. Would not natural selection also impact these interactions, the same interactions that were originated by the organism, and traceable back to that organism's genetic code? In response to the next question I will delve more deeply into specific situations, but consider these points:

 

-All organisms interact with their environment

-Behaviour (interactions) is due to chemical, physiological, mechanical constraints

-Constraints are induced by availability of genetic material (ie an organism's genetic makeup determines what it can and cannot do)

-Environment, through natural selection, drives evolution

-Interactions between organisms and environement drive environmental change

 

We see a loop where organisms interact with their environment, and the environment selects for individuals with the highest reproductive success. Therefore, organisms will be the most successful if they can manipulate the environmen to give them the highest total reproductive success. These manipulations are due to the genetic code. So, it follows that DNA is using its 'host' as a proxy to select for the most reproductively successful individuals, to continue passing on the DNA.

 

In short, the point that new genetic material is the result of random mutations is moot.

 

 

I think the difference between my hypothesis and standard Darwinian theory is the incorporation of a self-perpetuated selection loop. That probably makes no sense.

 

What I am trying to describe is the relationship between the agent (in this case, any organism) and its manipulation of the environment; a loop exists between agent and interactions with the environment. The organism changes the environment in a way that creates a more optimal environment for its causes* (reproductive success) and in turn, alters the way that natural selection drives evolution for that species (and others in the same environment, as well).

 

Really, the only difference between my hypothesis and Darwin's is that I'm considering the changes that any organism may implement on its surroundings, which in turn alter Natural Selection over a longer period of time. The result is that species evolve to be suited for their habitat not only through random genetic mutations selected for by the environment (and certainly not through changes in that specific organism in its own lifetime, as you think I've been suggesting), but also indirectly through the changes that organism incurs to the environment (because the environment, Natural Selection, drives evolution).

 

It is not so much a novel hypothesis(?) as it is a proposed consequence of Natural Selection combined with agent-based environmental change. Since all organisms alter their environment in some way, I think that this consequence, if it holds true, is important when considering the evolutionary history of all organisms.

 

*An important caveat is that changes made to the environment are not necessarily beneficial to the organism. However, it still holds that these changes direct the 'direction' of Natural Selection (with the understanding that Natural Selection is in fact directionless, but for lack of a better word).

 

-Hyena

 

What you have described is standard Darwinian evolution. Just because you use different terminology does not mean that your idea is novel or different.

 

I think one of the terms that best emphasizes this point is "coevolution", particularly since the example of a hummingbirds beak is a perfect example of this. Here you have a situation where two species evolve alongside each other, where the changes in one drive changes in the other. This can develop into a "loop" as the two species become increasingly specialized as they coevolve. Its not just that a hummingbird's beak fits certain flowers so well, but also that the flowers have evolved to fit the hummingbird in a loop of coevolution. The idea of coevolution dates back too Darwin himself, who really expounded upon it in Fertilization of Orchids. Sexual selection, particularly when it drives species to possess ever more grandiose traits, such as the peacocks tail, would be another example. We also have long known examples as it pertains to humans. Namely, as we have domesticated animals and plants, this has shaped our own evolution as it relates to our ability to consume and tolerate certain foods.

 

The point being that the idea that natural selection can act in a circular loop, often driving traits towards extremities, is not novel. Its been present in evolution since the beginning and expanded since.

 

One thing I learned quite a while ago is that there are a lot of smart people who have been working in biology for decades and typically, if you think you have a brand new idea, you probably don't.

[Hyena]

 

 

 

What you have described is standard Darwinian evolution. Just because you use different terminology does not mean that your idea is novel or different.

 

I think one of the terms that best emphasizes this point is "coevolution", particularly since the example of a hummingbirds beak is a perfect example of this. Here you have a situation where two species evolve alongside each other, where the changes in one drive changes in the other. This can develop into a "loop" as the two species become increasingly specialized as they coevolve. Its not just that a hummingbird's beak fits certain flowers so well, but also that the flowers have evolved to fit the hummingbird in a loop of coevolution. The idea of coevolution dates back too Darwin himself, who really expounded upon it in Fertilization of Orchids. Sexual selection, particularly when it drives species to possess ever more grandiose traits, such as the peacocks tail, would be another example. We also have long known examples as it pertains to humans. Namely, as we have domesticated animals and plants, this has shaped our own evolution as it relates to our ability to consume and tolerate certain foods.

 

The point being that the idea that natural selection can act in a circular loop, often driving traits towards extremities, is not novel. Its been present in evolution since the beginning and expanded since.

 

One thing I learned quite a while ago is that there are a lot of smart people who have been working in biology for decades and typically, if you think you have a brand new idea, you probably don't.

 

Aye, thank you. I didn't think I had a novel idea in that regard. More or less just an observation that, at least with my education on the matter, is sometimes... overlooked.

 

So, then, the aforementioned debate as to whether or not DNA alters itself is correct? It does so indirectly through 'host' co-evolution with the environment.

 

And, possibly (probably) off-topic, what, if anything, is there to say about this co-evolution when considering introduced species and their successes? Is it an underlying trait of successful invasives to more readily capitalize on the changes associated with the co-evolution of species and environment?

 

On another, more personal note, I apoligize for coming across as arrogant or entitled to this idea, if it is indeed the case that I have done so. I just enjoy thinking about this kind of stuff, and as such, my passion for the subject sometimes tends to accidentally project an air of superiority. I do admit that I often get ahead of myself, sometimes to the point of reiterating ideas conceptualized long before my time. I'm just uncovering the same thoughts that others before me have understood with the same level of intensity and enthusiam, because that's what I like to do.

 

-Hyena

Edited June 10, 2014 by Hyena

[chadn737]

 

Aye, thank you. I didn't think I had a novel idea in that regard. More or less just an observation that, at least with my education on the matter, is sometimes... overlooked.

 

So, then, the aforementioned debate as to whether or not DNA alters itself is correct? It does so indirectly through 'host' co-evolution with the environment.

 

And, possibly (probably) off-topic, what, if anything, is there to say about this co-evolution when considering introduced species and their successes? Is it an underlying trait of successful invasives to more readily capitalize on the changes associated with the co-evolution of species and environment?

 

On another, more personal note, I apoligize for coming across as arrogant or entitled to this idea, if it is indeed the case that I have done so. I just enjoy thinking about this kind of stuff, and as such, my passion for the subject sometimes tends to accidentally project an air of superiority. I do admit that I often get ahead of myself, sometimes to the point of reiterating ideas conceptualized long before my time. I'm just uncovering the same thoughts that others before me have understood with the same level of intensity and enthusiam, because that's what I like to do.

 

-Hyena

 

DNA does not "alter itself". Maybe this is simply a confusion of words, but the DNA is not in directing in any fashion its own evolution. While organisms may alter their environment, shifting selection pressures, this does not mean that the DNA is driving the selection. For one, phenotypes are not determined wholly by DNA. It is a complex interaction between Genetics and Environment. While some traits are very heritable, others are less so, and some exhibit almost no heritability. Perhaps the most relevant kind of traits, behavioral, are often the most variable and exhibit some of the lowest degrees of heritability.

 

Humans alter their environment more than any other and often how we alter our environment is driven by cultural factors. But culture is not genetic. Yet it shapes our environment and ultimately the selective pressures on us.

[Mitch Bass]

 

For one, phenotypes are not determined wholly by DNA. It is a complex interaction between Genetics and Environment. While some traits are very heritable, others are less so, and some exhibit almost no heritability.

 

Its been a few years since I read the follow up book by Charles Dawkins to his book The Selfish Gene, but that book was named The Extended Phenotype. If you are correct than my memory of some of what I learned from his book I never did learn. Or rather i should, one idea thought I thought I learned was never taught. I thought the definition of an Exteneded Phenotype was the organism created which was determined by DNA. From what you just wrote though I would very much like to understand what it is that you are defining as a "phenotype". Do you know why Dawkins followed up the book he wrote The Selfish Gene, with the Extended Phenotype. (this being said I don't even know which book came out first). This post I had guessed was based on the ideas Dawkins brought into being with his book the Selfish Gene. I have read that book and as I said I have read The Extended Phenotype. Being as deep as you are into this thread, the seventh page now, I am guessing with a good deal of certainty you have a depth of comprehension into the conceptual idea of the Selish Gene. I am hoping you can give me some of what you know about the basic idea behind the book The Extended Phenotype,

[chadn737]

Its been a few years since I read the follow up book by Charles Dawkins to his book The Selfish Gene, but that book was named The Extended Phenotype. If you are correct than my memory of some of what I learned from his book I never did learn. Or rather i should, one idea thought I thought I learned was never taught. I thought the definition of an Exteneded Phenotype was the organism created which was determined by DNA. From what you just wrote though I would very much like to understand what it is that you are defining as a "phenotype". Do you know why Dawkins followed up the book he wrote The Selfish Gene, with the Extended Phenotype. (this being said I don't even know which book came out first). This post I had guessed was based on the ideas Dawkins brought into being with his book the Selfish Gene. I have read that book and as I said I have read The Extended Phenotype. Being as deep as you are into this thread, the seventh page now, I am guessing with a good deal of certainty you have a depth of comprehension into the conceptual idea of the Selish Gene. I am hoping you can give me some of what you know about the basic idea behind the book The Extended Phenotype,

 

The Extended Phenotype argues that we cannot limit the definition of phenotype to the biology of an organism alone, but should extend it to include culture and how we influence our surroundings.

 

However, that does not meant that this or even our biology is determined exclusively by genetics. There is always a dynamic interaction between genetics and environment.

 

The way to think about it is to consider the effect of the gene as defining a range of possibilities. Typically when people think about the effect of a gene variant they think in regards to simple traits, where the effects are binary. For example, if a pea has the allele for a yellow color, the pea will be yellow, otherwise it will be green. For some simple traits, that is true. However, for most traits, it is more appropriate to think of an allele as defining a range of values. For example, lets say you have a particular allele that influences height. It is more appropriate to think that this particular allele will allow you to grow to a height within a range of 5.0 ft to 5.7 ft. If you are malnourished, then you will not reach the full potential that this allele will allow you to grow to, so you may only be 5.0 ft tall. If you grew up without disease and are properly nourished, you may achieve 5.7 ft. When you think of it in terms of a range of values, then that gives room for environmental factors to also shape the final outcome. Someone else with a different allele may be able to achieve a maximum height of 6.1, but if environmental influences are such, they may not reach the full potential. Gene variants for many, maybe most traits are potentialities.

 

Does that help clear things up?

Edited June 11, 2014 by chadn737

[SUN7867]

The Selfish Gene theory is beautifully shown when observing the behaviour of certain bird species especially.

 

I remember studying about the Selfish Gene back in 3rd year University Zoology, under behavioural ecology. Nice thread

I was shocked when I read this book because it is crazy..i mean absolutely crazy that all that we believed throughout our life is turned upside down.

 

But what stumps me is how is the DNA able to think about replicating itself. I mean how and when it decided that "let me copy myself endlessly" how does it know that adaptation is required..how does it store the memory?

Is this like the Matrix movie come true?

Below is another book from google which is also very interesting

https://books.google.ae/books?id=gib3SwqcH8AC&pg=PA16&lpg=PA16&dq=HUMANS+ARE+JUST+ROBOT+VEHICLES+FOR+GENES&source=bl&ots=usB4juB7a5&sig=500paoqVhPXk-M8z7d5g-7rRBpY&hl=en&sa=X&ved=0CEEQ6AEwB2oVChMI0cLss7_wxgIVAroUCh3wdgkA#v=onepage&q&f=false