Evolution? Good Discussion here

[DR_henegar]

I can probably argue against evolution without biblical references? Anyone wish to hear my argument?

 

[bobze]

Sure

 

[ZapperZ]

I can probably argue against evolution without biblical references? Anyone wish to hear my argument?

You do so at your own risk, per the https://www.physicsforums.com/showthread.php?t=414380" that you had agreed to regarding speculative, personal theory.

Zz.

 

[Fredrik]

You should also check out one of the many evolution FAQs available online, to see if your arguments have already been refuted. Try this one for example. If you want to speculate beyond what the forum rules allow, the JREF forum is a good place to do that.

 

[thE3nigma]

Still if the man says he has references that are not religious then let's here him out. I think that is a very important part of science, because without open discussion I do not think any field of science will ever advance.

In response to the OP, I wouldn't mind hearing your arguments.

 

[Kglocc]

Yeah I'm interested to hear what you have to say. Send me a message with your argument please.

 

[Gokul43201]

Still if the man says he has references that are not religious then let's here him out. I think that is a very important part of science, because without open discussion I do not think any field of science will ever advance.

Very good. You should feel free to host or suggest a forum where anyone can post their personal speculation. PF is not that place.

If the OP has references from acceptable peer reviewed journals, then that's definitely fair game here.

 

[thE3nigma]

Well as far as my common sense tells me, that is what the OP had in mind. By the way, I have done some of my own research and discussed certain topics on this such issue with Professors, and I have to honestly say there are a lot of problems with this Theory still. PF should not hide this fact just because the media "thinks" Evolution is complete and perfect; it is far from anything like that.

 

[Evo]

Well as far as my common sense tells me, that is what the OP had in mind. By the way, I have done some of my own research and discussed certain topics on this such issue with Professors, and I have to honestly say there are a lot of problems with this Theory still. PF should not hide this fact just because the media "thinks" Evolution is complete and perfect; it is far from anything like that.

Hide what? Evolution has been accurately presented in this forum. Do you know what a theory is? Do you understand what the theory of evolution is? A theory is never "complete and perfect" to use your own words.

 

[DaveC426913]

...there are a lot of problems with this Theory still. PF should not hide this fact just because the media "thinks" Evolution is complete and perfect; it is far from anything like that.

Not only does no serious scientist think evolution is complete or perfect but I'm pretty sure this "media" you speak of does not think that either.

I'd say you're trying to stir a pot.

What you need to understand is that PF is first and foremost a source for mainstream science (taught in schools). There are plenty of fora for flogging speculative hypotheses; this just isn't one of them.

 

[russ_watters]

Still if the man says he has references that are not religious then let's here him out. I think that is a very important part of science, because without open discussion I do not think any field of science will ever advance.

In response to the OP, I wouldn't mind hearing your arguments.

Don't hold your breath for something new and exciting. I'd be willing to bet a rediculous amount of money that the idea the OP has is just one of the several typical/common misconceptions about evolution that we've all heard dozens of times.

 

[thE3nigma]

Please do not get me wrong. I firstly did not try in any way to stir up a debate, or a pot? seriously? :). The only thing I was trying to say is I believe what the OP will talk about is clearly those areas in which we lack understanding. Obviously though, this is something we have to accept, and these areas which lack understanding aren't speculative hypothesis or anything, it is just a part of the working Theory.

 

[bobze]

Please do not get me wrong. I firstly did not try in any way to stir up a debate, or a pot? seriously? :). The only thing I was trying to say is I believe what the OP will talk about is clearly those areas in which we lack understanding. Obviously though, this is something we have to accept, and these areas which lack understanding aren't speculative hypothesis or anything, it is just a part of the working Theory.

Out of curiosity, what areas do you believe evolutionary theory to be "lacking"?

 

[thE3nigma]

Well since I do prefer genetics myself mostly, I can only speak primarily about that area itself as related to evolution. One such question is how variation truly arises. I know the common mainstream answer: mutation. And although I agree with that answer to a certain aspect, as in primarily within single-celled organisms; I do not believe it is the only answer or even the main process of variation creation within higher-order species. The reason I ask this question, is because science has yet to provide any concrete example of a perfect variation according to mutations. Most of the experiments I have seen and read about have produced no new useful traits.

 

[DaveC426913]

...any concrete example of a perfect variation according to mutations. Most of the experiments I have seen and read about have produced no new useful traits.

Wait. What?

What is a 'perfect' variation?
What would you consider a 'useful' trait?

I have a feeling I know where this is headed...

 

[thE3nigma]

Well why don't I ask you Mr. Dave what a useful trait. According to the Theory, a useful trait would be anything that helps the species or individual at least, become adapted to his new environment. That is all it is. As far as I know, most studies that have placed any form of stress or say change in the environment of a species have not produced a change in that species that was helpful to it in any way. This is obviously not true for single celled organisms which have immediate phenotype changes upon mutation.

You know I would love to actually hear something smart from you once Mr. Dave. All you keep doing is replying with one liners that aren't really helping this conversation go anywhere. Feedback would be appreciated. I assume that is what the role and goal of PF is, correct?

 

[cesiumfrog]

How about the experiment in which E.coli, by a sequence of random mutations, developed the new ability to digest a different abundant food source (and ceased to be E.coli)?

 

[Gokul43201]

That is all it is. As far as I know, most studies that have placed any form of stress or say change in the environment of a species have not produced a change in that species that was helpful to it in any way.

Needs citations to the studies.

 

[Gokul43201]

How about the experiment in which E.coli, by a sequence of random mutations, developed the new ability to digest a different abundant food source (and ceased to be E.coli)?

This too.

 

[Ken Natton]

I’m interested to know Gokul43201 what your opinion of the type of contributions I offer is. Believe me, I am not fishing for compliments, I have a serious point to make. If these forums really are only for contributions from well studied people with the capability to offer citations for every assertion, then clearly I should leave. I have made no secret of the fact that I am a layman, and I simply do not possesses that ability. I do, however, believe I have something to contribute to the discussion with thE3nigma. I have nothing particularly to offer to DR henegar, I share the scepticism that his or her argument will offer anything remotely original, and I also have a deep suspicion, borne of experience, about the good doctor’s true motivations.

So, thE3nigma, discussions on these matters tend to be littered with assertions like ‘…clearly those areas in which we lack understanding.’ And almost invariably, they cite some area in which, in fact, the understanding is very good. You mention a ‘preference’ for genetics, and if by that, you mean that you have genuine knowledge and experience of formal study in that area, then you almost certainly know a good deal more than me. But your post (#16) does reflect a recognisable naivety, one that I freely admit I was once a possessor of, but that I improved from, purely by a little bit of reading and by engagement with forums like this one.

Before I offer you a very good example of a study that identified ‘a change in a species that was helpful to it’ let me just offer one piece of terminology that might seem like hair splitting, but actually, I contend, is significant. Rather than ‘useful traits’, most of the knowledgeable people I have read tend to talk about traits that offer a ‘selective advantage’. The study that I wanted to mention is so familiar to this discussion I can even refer to its usual formal title: ‘Industrial Melanism in the Peppered Moth’. Briefly, the basis is this. The peppered moth originally had an essentially white colouring, with speckled black patterns that varied between individual moths. During the era of industrialisation, because of pollution, lichens had a tendency to become sooted and blackened. Because lighter coloured moths stood out more against this dark background, predators found them easier to catch, and having darker colouring thus offered a selective advantage. Within just a few generations, peppered moths became predominantly black in appearance. Then along came the clean air act, and lichens returned to their natural green colouring. Suddenly it was the darker moths that stood out the most and within another few generations, peppered moths had returned to their former colouring. This is only one example of observed, naturally occurring evolution, and even industrial melanism is not exclusive to the peppered moth.

 

[Kglocc]

Well since I do prefer genetics myself mostly, I can only speak primarily about that area itself as related to evolution. One such question is how variation truly arises. I know the common mainstream answer: mutation. And although I agree with that answer to a certain aspect, as in primarily within single-celled organisms; I do not believe it is the only answer or even the main process of variation creation within higher-order species. The reason I ask this question, is because science has yet to provide any concrete example of a perfect variation according to mutations. Most of the experiments I have seen and read about have produced no new useful traits.

Well why don't I ask you Mr. Dave what a useful trait. According to the Theory, a useful trait would be anything that helps the species or individual at least, become adapted to his new environment. That is all it is. As far as I know, most studies that have placed any form of stress or say change in the environment of a species have not produced a change in that species that was helpful to it in any way. This is obviously not true for single celled organisms which have immediate phenotype changes upon mutation.

You know I would love to actually hear something smart from you once Mr. Dave. All you keep doing is replying with one liners that aren't really helping this conversation go anywhere. Feedback would be appreciated. I assume that is what the role and goal of PF is, correct?

Gah, read more. quit confusing me, and try not to insult people please, we are here to learn. Get your facts lay them them straight. 10 minute search =
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2806358/
http://onlinelibrary.wiley.com/doi/10.1002/1521-1878%28200012%2922:12%3C1057::AID-BIES3%3E3.0.CO;2-W/abstract
http://onlinelibrary.wiley.com/doi/10.1111/j.0014-3820.2000.tb01232.x/abstract
http://onlinelibrary.wiley.com/doi/10.1111/j.0014-3820.2003.tb01561.x/abstract
http://www.genetics.org/cgi/content/abstract/168/4/1817

 

[Gokul43201]

If these forums really are only for contributions from well studied people with the capability to offer citations for every assertion, then clearly I should leave.

Not all assertions need citation. Many are common knowledge and/or generally uncontroversial.

Some assertions beg for a citation. For example when someone says that they have read papers that claim XYZ, it is automatically incumbent upon them to cite some of these papers. If you as discussing a scientific study, it is not an unreasonable requirement that you have to cite the study so that others may read it too and therefore be able to better understand or challenge any arguments that are based on that study.

Peppered moth evolution is ripe hunting ground for any well-read proponent of creationism/ID. Heck, there may be more Creationinst literature in that field than there is from Biology!

 

[cesiumfrog]

This too.

http://lmgtfy.com/?q=e+coli+mutation+experiment&l=1"

 

[Gokul43201]

http://lmgtfy.com/?q=e+coli+mutation+experiment&l=1"

Thank you, smarty-pants!

It's your job to give us better citations for your references, not ours to have to hunt them down.

I tried before asking.

 

[cesiumfrog]

I tried before asking.

Your first hit (creationwiki) is actually relevent, it raises questions as to the validity of my example.

 

[DaveC426913]

As far as I know, most studies that have placed any form of stress or say change in the environment of a species have not produced a change in that species that was helpful to it in any way.

This shows a profound misunderstanding of how evolution works. This is what I was concerned about.

You know I would love to actually hear something smart from you once Mr. Dave. All you keep doing is replying with one liners that aren't really helping this conversation go anywhere. Feedback would be appreciated.

Feedback, sure. Education, no.

This isn't really going to be a discussion, it's going to be a lesson. Online fora are not the place for in-depth lessons, that's for classrooms and textbooks.





But OK, in a very tiny, overly-simplified nutshell:

Evolution does not produce 'useful' and 'not useful' mutations. It produces things that are different. It takes generations of pressure in a large population, in the vastness of the environment before some trait that was neither good nor bad to start having unintended side effects. These unintended side effects made no difference at first but when things change (say, a new competitor invades the geographical area) that this side effect suddenly seems to have a silver lining.

One common example: sickle cell anemia in humans. Terrible affliction. By no means useful or even beneficial.

That is, until a new species of malaria-bearing mosquito made its presence known. Those with anemia, once clambering for survival, now found themelves more able to survive outbreaks of malaria than their non-mutated brethren.


If, tomorrow, you saw mutated, malformed red blood cells in your new lab specimen that were adversely affecting its health - would you write in your report that you had isolated a 'perfect variation' or a 'useful trait'?

 

[thE3nigma]

This shows a profound misunderstanding of how evolution works. This is what I was concerned about.

...

If, tomorrow, you saw mutated, malformed red blood cells in your new lab specimen that were adversely affecting its health - would you write in your report that you had isolated a 'perfect variation' or a 'useful trait'?

Of course I wouldn't say that, who in their right mind would? It is a mutation that is causing a problem for that specimen not anything else. Obviously though you have brought up a good example of this with anemia, that is when it would be useful.

I do not think my understanding of how evolution works is flawed, maybe not full or complete, but then who's is really? What I said earlier still applies. When doing fly experiments with Drosophila melanogaster that were placed under pressure in a controlled environment, the population was never shown to exhibit any selective adaptation. The reason I believe this to be, may be because mutation in higher-ordered organisms like the above mentioned species plays a minute role in its adaptation and evolution - that is the variability in its genetic pool.

I understand your point that the mutation occurred before any selective pressure was introduced into the environment, and I obviously have nothing against this nor did my example.

@Kglocc,
Aren't most of those examples dealing with adaptation and evolution of single-celled species? You told me not to insult anyone, you seem to have insulted me quite clearly by not reading my second post that you quoted. I clearly said I accept and agree that mutation within the organisms is one of the most important forces to their variation; but i don't think so that the same is true for higher-order organisms.

 

[arildno]

When doing fly experiments with Drosophila melanogaster that were placed under pressure in a controlled environment, the population was never shown to exhibit any selective adaptation

Do give us a reference to that work, please.

 

[bobze]

Of course I wouldn't say that, who in their right mind would? It is a mutation that is causing a problem for that specimen not anything else. Obviously though you have brought up a good example of this with anemia, that is when it would be useful.

I do not think my understanding of how evolution works is flawed, maybe not full or complete, but then who's is really? What I said earlier still applies. When doing fly experiments with Drosophila melanogaster that were placed under pressure in a controlled environment, the population was never shown to exhibit any selective adaptation. The reason I believe this to be, may be because mutation in higher-ordered organisms like the above mentioned species plays a minute role in its adaptation and evolution - that is the variability in its genetic pool.

I understand your point that the mutation occurred before any selective pressure was introduced into the environment, and I obviously have nothing against this nor did my example.

@Kglocc,
Aren't most of those examples dealing with adaptation and evolution of single-celled species? You told me not to insult anyone, you seem to have insulted me quite clearly by not reading my second post that you quoted. I clearly said I accept and agree that mutation within the organisms is one of the most important forces to their variation; but i don't think so that the same is true for higher-order organisms.

Variation arises by two sources mutations and sexual recombination. The term "mutation" is vague, ambiguous and misleading to those not well studied in biology. Since you said you express interest in genetics, in particular, you should get used to distinguishing between them. For instance, when you say mutation do you mean a UV induced thymine dimerization? Do you mean a translocation that leads to gene duplication? Point mutation? Cryptic splice?

As I pointed out in another topic, there are literally thousands of examples of these changes which provide positive or negative selective value, far to many to start any kind of comprehensive list here.

As Dave points out, this really isn't a problem with evolution, but rather your education regarding evolution--And I mean no offense by that.

Anyway a few examples you could look into would be the lactose gene in humans, mutant allele CCR5 receptors in populations who were descendants of populations who experienced strong selective pressures from plague and smallpox, oxygen loading genes in Tibetans vs similarly geographically located Hans Chinese, etc

And also to clarify with the sickle cell anemia (SCA) its not the disease which necessarily confers evolutionary advantage. In fact, left untreated SCA patients often die before reproductive age.

The pudding in this case lies in something we call the "heterozygote advantage". Both hemoglobin (Hb) genes are used to make Hb. In the case of heterozygote patients (HbA/HbS, where HbA is the "normally Hb Adult allele"), that means a small amount of the sickle beta-globin will be incorporated into Hb tetramers (Hb is a tetramer protein, made of 2 dimers, each made of 2 beta units and 2 alpha units). Because HbA/HbS individuals have some sickle beta globin protein, they have lower bloodox levels and thus a greater resistance to the malaria parasite.

Evolutionary selection then, favors those individuals HbA/HbS in areas of epidemic malaria. Of course Nature's unintended consequence of increasing HbA/HbS individuals means that the frequency of full blown disease (HbS/HbS) increases.

 

[DaveC426913]

Of course I wouldn't say that, who in their right mind would? It is a mutation that is causing a problem for that specimen not anything else.

And yet, when the results are tallied, it may well result in a population that, a thousand generations from now, has incorporated that trait just like any other trait that helps us stay alive.

The trouble is what we see as a "benefit" with our short-term mindset has nothing to do with what nature selects for.

You are looking to controlled experiments and seeing that they "fail" to turn up the results you expect. I'm saying your expectations are flawed.

 

[cosmos 2.0]

The sickle cell anemia is a classic example of how a group of individuals who had a particular trait where able to survive malaria (because the parasite cannot infect the sickle cell rbc's).

 

[DaveC426913]

The sickle cell anemia is a classic example of how a group of individuals who had a particular trait where able to survive malaria (because the parasite cannot infect the sickle cell rbc's).

Yes. The point being that we would never have labelled anemia as anything like what ThE3nigma calls a "useful trait".

But nature doesn't work on "useful". Nature simply let's poplutions do their thing, and creatures change over time. It is only the gift of hindsight that allows us to declare that something is a "useful trait".

And it's self-fulfilling. ("Of course reverse peristalsis is a useful trait. We're here aren't we?")

 

[cosmos 2.0]

Yes. The point being that we would never have labelled anemia as anything like what ThE3nigma calls a "useful trait".

But nature doesn't work on "useful". Nature simply let's poplutions do their thing, and creatures change over time. It is only the gift of hindsight that allows us to declare that something is a "useful trait".

And it's self-fulfilling. ("Of course reverse peristalsis is a useful trait. We're here aren't we?")

well anemia definitely by no means is a useful trait. but it was is was regional pressure or a geographical pressure that selected a particular trait.

we don't need reverse peristalsis because we cook our food

 

[Kglocc]

reply@the3nigma - Yeah I apologize, that was not my intention. 3am after a long night was not a considerate time to post on my part. I have reread your posts, and the abstracts I linked.

Evidence that random mutations surviving in the genepool are rare even in single celled organisms and mostly deleterious to fitness.
And I agree that if a morphological/phisiological mutation occurs the possibility remains such that,

... when the results are tallied, it may well result in a population that, a thousand generations from now, has incorporated that trait just like any other trait that helps us stay alive.

Two thousand human generations goes back (~25yrsX2000G=) about 50,000 years. I feel that is a reasonable timescale to observe for mutations to be effecting our or any complex multicellular population. Most research I found observed 20-200 generations.

However,
Now that I understand your position I am supportive. Sorry about that previous post, I misunderstood. Do you have evidence? What other mechanisms of evolution do you propose?
On viral infection - "HERVs [Human endogenous retro-virus] might have conferred antiviral resistance on early human ancestors, thus helping them to survive. ...HERVs could have changed the pattern of gene expression and therefore played a significant role in the evolution and divergence of Hominoidea superfamily." http://onlinelibrary.wiley.com.oca....00002)22:2<161::AID-BIES7>3.0.CO;2-X/abstract

By the way, I haven't heard from DrHenegar in a while... I'm doubting the existence of any bliblical referenceless anti-evolution argument.

 

[thE3nigma]

reply@the3nigma - Yeah I apologize, that was not my intention. 3am after a long night was not a considerate time to post on my part. I have reread your posts, and the abstracts I linked.

Evidence that random mutations surviving in the genepool are rare even in single celled organisms and mostly deleterious to fitness.
And I agree that if a morphological/phisiological mutation occurs the possibility remains such that,

Two thousand human generations goes back (~25yrsX2000G=) about 50,000 years. I feel that is a reasonable timescale to observe for mutations to be effecting our or any complex multicellular population. Most research I found observed 20-200 generations.

However,
Now that I understand your position I am supportive. Sorry about that previous post, I misunderstood. Do you have evidence? What other mechanisms of evolution do you propose?
On viral infection - "HERVs [Human endogenous retro-virus] might have conferred antiviral resistance on early human ancestors, thus helping them to survive. ...HERVs could have changed the pattern of gene expression and therefore played a significant role in the evolution and divergence of Hominoidea superfamily." http://onlinelibrary.wiley.com.oca....00002)22:2<161::AID-BIES7>3.0.CO;2-X/abstract

By the way, I haven't heard from DrHenegar in a while... I'm doubting the existence of any bliblical referenceless anti-evolution argument.

That is ok no problem at all, I understand the dreaded late night work, .

@Bobze,
Sorry about screwing up the grammar and vocabulary when speaking about Evolution, I'll try to improve upon that.

But with respect to your other points, you are right I should be more specific about what I mean when it comes to mutation.

@Kglocc,
When I meant other mechanisms of variation I did not have any specific ones in mind. But I will try to look around for some examples when I get the chance.

I am also wondering where the OP is.

P.S.
I am sorry if I have offended or angered anyone with my comments up to this point. I am still just a student so my education is constantly ongoing and I am learning as I go. I will take all your comments into account and try to improve my understanding.

 

[bobze]

That is ok no problem at all, I understand the dreaded late night work, .

@Bobze,
Sorry about screwing up the grammar and vocabulary when speaking about Evolution, I'll try to improve upon that.

But with respect to your other points, you are right I should be more specific about what I mean when it comes to mutation.

No problem at all.

@Kglocc,
When I meant other mechanisms of variation I did not have any specific ones in mind. But I will try to look around for some examples when I get the chance.

I am also wondering where the OP is.

Kglocc brought up a great one, HERVs, a significant portion of our genomes is actually given over to these little guys. But, as I pointed out, the bulk of variation for natural selection to "chew on" comes from sex and the broad (very broad) category of mutation.

Certainly other minor sources play a role and sometimes that role is increased or decreased depending on the lineage. Prokaryotes exchange genes with each other (to the point of scary abandon) in a process we call lateral (or horizontal) gene transfer (LGT).

Eukaryotes too, have partaken in LGT through endosymbiotic relationships.

Plants seem especially prone to LGT through the auspice of viruses. And they go out of their way to hybridize (something I'd consider another source of variation) and make a real mockery of gene pools.

Epigenetics, which deals with the "state" DNA is inherited in may play a role. DNA is passed from parental cell to daughter cell in "preconfigured" states, which mostly involves the methylation of different regions of DNA. Methylation plays a key role in gene expression. While it has become very apparent over the past 10 years the importance of this in medicine, the evolutionary implications are not well understood. In theory, during gametogenesis and early embryonic gamete development, the "state" of DNA should be reset. You wouldn't want your offspring inheriting DNA in that "state" of say, a plasma cell where very few genes are "turned on".

It seems, that "resetting" the "state" may not always happen, the way it should. Which means, you potentially alter the timing or expression of genes during development. Something which could potentially have huge implications for evolution.

Anyway, the answer to your most immediate question is "yes" there is more to variation than just mutations. But as I said before, drill into your head "mutation and sex" as those are by far and away the most accountable in evolution.

P.S.
I am sorry if I have offended or angered anyone with my comments up to this point. I am still just a student so my education is constantly ongoing and I am learning as I go. I will take all your comments into account and try to improve my understanding.

We should endeavor to make learning a life long processes. One's education can never be complete. Even the great master Michelangelo had, on a sign written in his workshop, in his latter days; "Ancora Imparo". Understand that phrase like Michelangelo and you'll be alright

 

[cosmos 2.0]

Kglocc brought up a great one, HERVs, a significant portion of our genomes is actually given over to these little guys. But, as I pointed out, the bulk of variation for natural selection to "chew on" comes from sex and the broad (very broad) category of mutation.

Certainly other minor sources play a role and sometimes that role is increased or decreased depending on the lineage. Prokaryotes exchange genes with each other (to the point of scary abandon) in a process we call lateral (or horizontal) gene transfer (LGT).

Eukaryotes too, have partaken in LGT through endosymbiotic relationships.

Plants seem especially prone to LGT through the auspice of viruses. And they go out of their way to hybridize (something I'd consider another source of variation) and make a real mockery of gene pools.

Epigenetics, which deals with the "state" DNA is inherited in may play a role. DNA is passed from parental cell to daughter cell in "preconfigured" states, which mostly involves the methylation of different regions of DNA. Methylation plays a key role in gene expression. While it has become very apparent over the past 10 years the importance of this in medicine, the evolutionary implications are not well understood. In theory, during gametogenesis and early embryonic gamete development, the "state" of DNA should be reset. You wouldn't want your offspring inheriting DNA in that "state" of say, a plasma cell where very few genes are "turned on".

It seems, that "resetting" the "state" may not always happen, the way it should. Which means, you potentially alter the timing or expression of genes during development. Something which could potentially have huge implications for evolution.

Anyway, the answer to your most immediate question is "yes" there is more to variation than just mutations. But as I said before, drill into your head "mutation and sex" as those are by far and away the most accountable in evolution. :

Mutations and changes that occur over a long period of time may be useful for a particular species.
During gametogenesis especially homo sapiens the egg provides an environment for all genes to be turned on (stem cell) depending on cell differentiation .

 

[bobze]

Mutations and changes that occur over a long period of time may be useful for a particular species.
During gametogenesis especially homo sapiens the egg provides an environment for all genes to be turned on (stem cell) depending on cell differentiation .

That is, for the most part true. Of course not all genes are really turned on, rather they are set to a sort of "default state", where differentiating cell lines can access them. Something not generally possible to cells once differentiated (though such a reversion can be induced through transformations of cell lines with viral delivery systems).

The point I was making for TheEnigma, who was inquiring about other modes of variation in evolution, was that sometimes that process doesn't quite work out. Paramutations, are really epigenetic inheritances that violate Mendel's Law of assortment.

Of course, transgenerational epigenetic inheritance (the only type which could affect evolution) is seen more prominently in organisms like plants, prokaryotes and other microbes. All of which seem more than willing to take their genomes to the casino.

Obviously, transgenerational epigenetic inheritance would provide a pretty strong selective advantage for reversible phenotypes. Suppose for a moment, you had two food sources and two different genes needed to digest those sources. You turned one gene "off" when its corresponding food source wasn't present. If you could bequeath to your offspring the correct active gene as per your environment, you could them a "evolutionary leg up". Saving them time and energy costs of sorting out which gene to "activate" on their own.

Such a thing sounds pretty incredible and more akin to some kind of Lamarckian evolution. However, there is evidence to show that such a thing can happen in mammals even¹. And we've known since the 40's (maybe it was the 50's, I can't remember at the moment) that certain plant alleles can modulate the inheritance of others.

Its also been postulated that transgenerational epigenetic inheritance may play a role in protecting certain genes from mutation (at least certain types of mutations).
"[URL
There was an interesting review of epigenetic inheritance examples published back in 2009.[/URL]

You might also find interestinghttp://www.nescent.org/science/awards_summary.php?id=92" on what role epigenetic variation may play on phenotypic evolution.

1. http://www.fasebj.org/cgi/content/full/12/11/949"

Edit: I realize the first two links require a subscription, for those of you who are students and attending a college which provides you with subscription to scientific literature, then simply do an "off-campus sign-in" for your library and copy the ".proxy.schoolname.edu" into the link after the ".org" or ".edu" for access. Those of you without access, but who maybe interested--I'd invest in library card :)

 

[Mkorr]

The E. coli experiments probably refers to the E. coli long-term evolution experiment carried out by Lenski et. al.

Blount, Z. D., C. Z. Borland, and R. E. Lenski. 2008. Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli. Proceedings of the National Academy of Sciences, USA 105:7899-7906. (http://www.pnas.org/content/105/23/7899.abstract).

Barrick, J. E., D. S. Yu, S. H. Yoon, H. Jeong, T. K. Oh, D. Schneider, R. E. Lenski, and J. F. Kim. 2009. Genome evolution and adaptation in a long-term experiment with Escherichia coli. Nature 461:1243-1247. (http://www.nature.com/nature/journal/v461/n7268/full/nature08480.html).

etc.

This, along with many other examples, refutes the creationist gambit that no beneficial mutations has been observed.

 

[nismaratwork]

How on Earth has this thread gone for 3 pages when the OP simply issued a vague challenge and then retreated without comment? What IS this thread at this point anyway? This doesn't seem productive to me, so why not split into relevant threads that address a given OP instead of this crap? Someone, for the love of dog, lock the thread. :)

 

[DaveC426913]

How on Earth has this thread gone for 3 pages when the OP simply issued a vague challenge and then retreated without comment? What IS this thread at this point anyway?

Agree, the OP has fallen off the face of the Earth.

It picked up steam in post 13/14 wherein the question was asked what problems or weaknesses evolution currently suffers from.

ThE3nigma has suggested that lab tests have not shown diversity effects we might expect. Counter arguments revolve around what we should expect and what we are seeing.

Then nismaralatwork came along and wondered what the heck is going...

Wait. I'll stop there. That's pretty much where we are.

 

[Ken Natton]

Well there are a few possibilities for what happened to Dr henegar. Perhaps he / she was scared off by the strong response his / her post garnered; perhaps he / she was persuaded that his / her argument wasn’t really all that original; or perhaps the good doctor achieved exactly what he / she intended – what DaveC426913 called ‘stirring the pot’. I‘m not sure it matters – as it turns out, his / her thread title was apposite. I confess that the discussion in the later posts on this thread is well beyond my knowledge and understanding, and I think that is well to the good – I reckon that I can tell the difference between when people are posting waffle and when they are talking at a level above mine.

And yet I do have a perspective to offer to the discussion of sickle red blood cells. My understanding is that not everyone who has sickle red blood cells suffers from sickle cell anaemia. The latter is quite a rare condition, but sickle red blood cells not so rare. If I was to cite my source, it would again only be a popular science book, so perhaps you are going to question the reliability of my source. But certainly, the point is, the connection between malaria and sickle red blood cells was not discovered by the scientific investigation of the kind of technicalities explained by bobze in post #29. It was essentially a statistician who observed that the map of malarial areas around the world nearly exactly coincided with the map of areas where sickle red blood cells were prevalent. Subsequent scientific investigation has developed the kind of understanding bobze explained to us. But again, that co-incidence of where malaria threatens and where sickle red blood cells have become common among the population is in itself evidence that it does constitute human evolution – a specific response to a specific threat.

 

[cesiumfrog]

Sickle cell anemia occurs if you inherit the gene from both parents. These people have an above average mortality rate. But the people who have only one copy of the gene have a below average mortality rate for malaria afflicted areas.

 

[nismaratwork]

Agree, the OP has fallen off the face of the Earth.

It picked up steam in post 13/14 wherein the question was asked what problems or weaknesses evolution currently suffers from.

ThE3nigma has suggested that lab tests have not shown diversity effects we might expect. Counter arguments revolve around what we should expect and what we are seeing.

Then nismaralatwork came along and wondered what the heck is going...

Wait. I'll stop there. That's pretty much where we are.

Heh, thanks for bringing me up to date DaveC.

 

[DR_henegar]

You say I have fallen? I am back. College is taking my time as of now. But you know, maybe I should have a moderator lock this discussion, however, if you really wish to hear my argument, please PM me. It is stirring trouble and when it stops stirring something is going to burn. I believe this should be locked before that happens. Please, for love of science, please don't bomb me with your theories without hearing mine. >.< That is all. I wish I could lock this thread m'self but I can't.

 

[bobze]

If you've got something scientific, let's hear it...

 

[DR_henegar]

Okay, Take this into consideration. Evolution is probable. However, the thing that bothers me most is you can not teach a monkey multiple languages, nor can you have a monkey learn Parkour because of the way it walks. But, is that my argument? No. My argument is of two conflicting theories: Darwin's The theory of Evolution, and Darwin's theory of Natural Selection. If you compare and contrast what those theories imply you might see a slight kink in the chain of Evolution.

 

[DR_henegar]

I'll be back around 1:00 EST

 

[nismaratwork]

Okay, Take this into consideration. Evolution is probable. However, the thing that bothers me most is you can not teach a monkey multiple languages, nor can you have a monkey learn Parkour because of the way it walks. But, is that my argument? No. My argument is of two conflicting theories: Darwin's The theory of Evolution, and Darwin's theory of Natural Selection. If you compare and contrast what those theories imply you might see a slight kink in the chain of Evolution.

That was so incredibly stupid it's making my head hurt. You just set up a straw man, killed him yourself, then restated your "thesis". That's not support, that's tap-dancing.