Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: norcalclimber on 04/06/2010 17:00:13
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From what I have always heard, both sharks(some) and crocodiles as well as a few others have not really evolved in the past 65 million years or so. It seems to me that all the species I have heard of which have not evolved are extremely well suited for their environment. Does this provide evidence that evolution happens as Jean Baptiste Lamarck suggested, because it is needed, and that if no evolution is needed no evolution occurs?
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That's not the normal meaning of Lamarkian evolution.
Some people are red headed, that's not a "needed" bit of evolution, but it happened anyway.
At best, the sharks suggest that evolution is slow in the absence of pressure to evolve.
There's also the point that there are many different sorts of sharks (and crocs), all derived from a common ancestor so the simple answer is "No".
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That's not the normal meaning of Lamarkian evolution.
Some people are red headed, that's not a "needed" bit of evolution, but it happened anyway.
At best, the sharks suggest that evolution is slow in the absence of pressure to evolve.
There's also the point that there are many different sorts of sharks (and crocs), all derived from a common ancestor so the simple answer is "No".
While I know there are some sharks(and crocs) which evolved during the past 65 million years, I was under the impression that there are also some which haven't just evolved "slowly", they haven't evolved at all...not even a little. This seems to suggest not that evolution is slow in the absence of pressure, but rather nonexistent. Seems to me that implies that evolution is a response to an environmental stressor, and not just the amplification of random traits.
And 65 million years is not a short period of time when it comes to evolution, since all life you see as well as millions of species which have gone extinct, didn't even really start evolving until ~750 million years ago.
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How can we know exactly what the sharks were like 65M years ago?
To support your claim you would need to recover DNA from them and prove that it was exactly the same as today's sharks' DNA.
The best we can say is that evolution is slow when there's no pressure to evolve.
So what?
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norcalclimber, I know you don't understand my previous posts of the Tasmanian Devil but I believe this is exactly what you are talking about here.
The Devils have genetically altered to mature earlier and to breed eariler due to their cancer which kills them within 3-4 months after getting it. This is the first documented case and supports Jean Baptiste Lamarck. This is adaptation happening as we see it, Now..
Prior to this cancer the gene pool was as clones for the Devil.
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That's not the normal meaning of Lamarkian evolution.
Some people are red headed, that's not a "needed" bit of evolution, but it happened anyway.
At best, the sharks suggest that evolution is slow in the absence of pressure to evolve.
There's also the point that there are many different sorts of sharks (and crocs), all derived from a common ancestor so the simple answer is "No".
While I know there are some sharks(and crocs) which evolved during the past 65 million years, I was under the impression that there are also some which haven't just evolved "slowly", they haven't evolved at all...not even a little. This seems to suggest not that evolution is slow in the absence of pressure, but rather nonexistent. Seems to me that implies that evolution is a response to an environmental stressor, and not just the amplification of random traits.
And 65 million years is not a short period of time when it comes to evolution, since all life you see as well as millions of species which have gone extinct, didn't even really start evolving until ~750 million years ago.
This assumes no pressure on these species - there could well be a selective pressure to not change - they are well adapted to their environment and lifestyle, and deviation from those adaptations might be selected against.
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norcalclimber, I know you don't understand my previous posts of the Tasmanian Devil but I believe this is exactly what you are talking about here.
I'm not so sure about that...
The Devils have genetically altered to mature earlier and to breed eariler due to their cancer which kills them within 3-4 months after getting it. This is the first documented case and supports Jean Baptiste Lamarck. This is adaptation happening as we see it, Now..
Prior to this cancer the gene pool was as clones for the Devil.
Well, the disease is leading to lifestyle changes - the devils are breeding earlier as a result of the disease. There's no need for there to have been any genetic change that leads to younger breeding - the tumour itself will change the ability of adult males to fight for mates.
This, in turn, may well lead to greater genetic variation, as more males are mating (rather than fewer, stronger males monopolising the females). This isn't Lamarkian - that would involve passing down acquired traits, of which there is no suggestion in the tasmanian devil's case.
In this case an environmental factor (the disease) is leading to population structure changes (earlier mating) which results in a different set of genes being passed on. Nothing out of the ordinary here.
In many ways, (and forgive me for speculating) we're seeing something similar in human populations - an environmental factor (medicine) leads to population changes (older couples having children) which change the set of genes that goes into the next generation.
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Most cancers are not infectious. The only reason these Devils have this problem is because they have very little genetic diversity. This in turn is because they were nearly wiped out and are now very inbred.
Their current behaviour- mating earlier- is an indirect response to an external stimulus; that stimulus is us.
Nothing to do with Lamarck.
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This assumes no pressure on these species - there could well be a selective pressure to not change - they are well adapted to their environment and lifestyle, and deviation from those adaptations might be selected against.
Ok, that makes sense. But it was my understanding that Lamarckian evolution basically said that evolution happens because it needs to happen, i.e. giraffes have long necks because they needed them, not by a series of totally random mutations over a few hundred million years. Under this, it makes sense that a species which is extremely well adapted to it's environment and had no need to change, would be selected against change, which makes sense to be the case here.
So what am I missing about the situation/science that makes me still feel like it fits a little better with Lamarckian evolution vs Darwinian evolution?
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Lamarkian evolution said that an giraffe would stretch its neck during its lifetime and thus its neck would become longer.. the newly lengthened neck would then be passed on to its offspring.
It is like saying that if I have a hand chopped off, and then have a child, the child is likely to be born with no hand.
In the light of modern knowledge, it sounds pretty daft. But Lamark didn't know about chromosomes, let alone genes (tho' he might have been expected to know at least in principle about industrial accidents and amputations).
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Lamarkian evolution said that an giraffe would stretch its neck during its lifetime and thus its neck would become longer.. the newly lengthened neck would then be passed on to its offspring.
It is like saying that if I have a hand chopped off, and then have a child, the child is likely to be born with no hand.
In the light of modern knowledge, it sounds pretty daft. But Lamark didn't know about chromosomes, let alone genes (tho' he might have been expected to know at least in principle about industrial accidents and amputations).
ahhhh, ok, thank you for the clarification.
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It may seem odd to consider this idea "It is like saying that if I have a hand chopped off, and then have a child, the child is likely to be born with no hand." but, if Lamarckian evolution worked, Jewish boys would be born with no foreskin.
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It may seem odd to consider this idea "It is like saying that if I have a hand chopped off, and then have a child, the child is likely to be born with no hand." but, if Lamarckian evolution worked, Jewish boys would be born with no foreskin.
Lol, point taken :)
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It may seem odd to consider this idea "It is like saying that if I have a hand chopped off, and then have a child, the child is likely to be born with no hand." but, if Lamarckian evolution worked, Jewish boys would be born with no foreskin.
Would that be similar to the French Bulldog and the Pembroke Welsh Corgi which are born with docked tails?
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It may seem odd to consider this idea "It is like saying that if I have a hand chopped off, and then have a child, the child is likely to be born with no hand." but, if Lamarckian evolution worked, Jewish boys would be born with no foreskin.
Would that be similar to the French Bulldog and the Pembroke Welsh Corgi which are born with docked tails?
No, not really.
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Would that be similar to the French Bulldog and the Pembroke Welsh Corgi which are born with docked tails?
The Cardigan Welsh Corgi (http://en.wikipedia.org/wiki/Cardigan_Welsh_Corgi) is born with a long tail, but without a cardigan.
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Would that be similar to the French Bulldog and the Pembroke Welsh Corgi which are born with docked tails?
Tail
Historically, the Pembroke was a breed with a natural bob tail (very short tail). Due to the advent of docking, the trait was not aggressively pursued, with breeders focusing instead on other characteristics and artificially shortening the tail when necessary. Given that some countries are now banning docking, breeders are again attempting to select for dogs with the genes for natural bob tails.
http://en.wikipedia.org/wiki/Pembroke_Welsh_Corgi (http://en.wikipedia.org/wiki/Pembroke_Welsh_Corgi)
they are born with short (not docked) tails - and it seems that more recently they are selectively bred for short(er) tails. dogs are an unusual case as they are almost entirely selectively bred - we have been choosing (either consciously or unconsciously) for desired traits over many thousands of generations. if you docked a labrador's tail (you should be locked up for starters), the progeny of this dog would not have a noticeably shorter tail. even if you did this over many generations you would merely select for dogs that were best able to cope with the procedure and whose ability to breed was unaffected - you would not, necessarily, end up with dogs with shorter tails.
lamarck is making a bit of a comeback recently - epigenetics has opened the possibility that not everything that is passable to next generation is received from previous generation (plus random mutation). together with an appraisal of what lamarck actually said, and a realisation that he shouldnt be bracketed with Lysenko, this has lead to a bit a of a re-reading for Lamarck
However, what is generally considered to be lamarckism - the inheritability of traits acquired over a single generation - is still not accepted.
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please read...http://jhered.oxfordjournals.org/cgi/reprint/100/2/236.pdf
C189G gene mutation accommodates the breeding of dogs that require tail docking for showing.
Now tail docking is outlawed.
The dogs with the C189G gene are bred more often for the desired effect for showing.
There are over 17 different dog breeds that carry this short tail gene.
I'm wondering if there has ever been a study done involving Jewish male children who have had their forskin removed to find out whether the forskin is shorter at birth now because of it!
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However, what is generally considered to be lamarckism - the inheritability of traits acquired over a single generation - is still not accepted.
Excepting wealth, there are other inherited traits we can not deny are passed down in a single generation. That's what makes us who we are. I look like my parents. half of my genes from dad the other half from mum.
Unfortunately gene mutations causes disease which can be also be inherited directly by the next generation.
If both dogs had their tail docked might they both have a gene mutation that caused their offspring to have a short tail? Are you suggesting that t only happens over vast periods of time?
Think about breast cancer, Alzheimer's and many more gene mutations are inherited by the next generation.
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If both dogs had their tail docked might they both have a gene mutation that caused their offspring to have a short tail?
Er well, no.
Dog breeders select a random characteristic of an individual (like, for example, a short tail) and reinforce the desired genetic characteristic by practices that we might consider incestuous in humans. This accelerates the genetic alteration to produce a particular breed in a relatively short time. Unfortunately, the consequent reduction in genetic diversity also reinforces certain undesirable genetic traits, like predispositions to certain abnormalities and susceptibility to particular diseases.
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Ancient Shepard's and herders docked their dog's tails to avoid paying taxes for them. To identify them as working dogs. the first records of naturally occuring bobtails that I have found shows that in the 1800's the taxes were abolished but people continued to dock tails for the show standards. It wasn't until 1800's that the first natural bobtail dog was recored an English sheep dog. The Pembroke Corgi was docked to distinguish it from a fox. The Pembroke corgi was also used for herding as far back as the 10th century.
Correct by selecting for specific visual characteristics to breed for conformity such as for short tail the Pembroke Corgi and the French Bulldog which are 2 dogs that usually have their tail docked if long, have developed a genetic mutation which can be inherited by their off spring. This is the C189G gene found in 17 -23 dog breeds. These 17-23 dog breeds are usually shown with docked tails to comply with the standards of the associations. But since this is now illegal to dock the tails the odd one or two dogs that are being born with this genetic mutation is being bred to satisfy the dog show standards. (This genetic mutation can also be lethal or cause small litters.)
This genetic mutation did happen, when can not be confirmed, somewhere in the 1800's I imagine due to records of natural bobtail dogs.
I would suggest this mutation came about due to docking dog's tails. All dogs that have natural bobtail genes are herding dogs.
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please read...http://jhered.oxfordjournals.org/cgi/reprint/100/2/236.pdf
C189G gene mutation accommodates the breeding of dogs that require tail docking for showing.
Now tail docking is outlawed.
The dogs with the C189G gene are bred more often for the desired effect for showing.
There are over 17 different dog breeds that carry this short tail gene.
To precis - there is possibly a ancestral (naturally occurring) mutation to a part of the dog genome that causes short tails. this trait is now regularly selected by human intervention. Corgis do not have the short tail because we would cut it off otherwise - they have short tail because we decide which dog breeds with which bitch.
Dogs exist because we humans are good at selecting breeding pairs that have a greater chance of reproducing preferred traits. there is no evidence of the genetic sequence being adapted within a single generation and thus allowing the inheritability of an acquired trait.
Excepting wealth, there are other inherited traits we can not deny are passed down in a single generation. That's what makes us who we are. I look like my parents. half of my genes from dad the other half from mum.
- please note difference between acquired trait and inherited trait
All the genetic characteristics that make echochartruse look like echochartruse were inherited from your parents through a combination of your mothers and fathers genes. if your father had lost a leg in an accident this would not be inherited. every single one of the genes (barring genetic damage/random mutation) that you pass onto your children will have come from your parents. no matter what traits you gain during your lifetime or changes to your bodily appearance - the genes you pass to your offspring will be those you received from your parents (again barring genetic damage/random mutation).
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I would suggest this mutation came about due to docking dog's tails.
This is Larmarckism - and there is no evidence to back it up. The article you quoted does NOT substantiate this claim in any way. Do you seriously believe; that given identical twins one of whom has lost a limb after an accident that the children of the 'amputee twin' will have different genetic inheritance than those of the 'non-amputee twin'?
Matthew
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To precis - there is possibly a ancestral (naturally occurring) mutation to a part of the dog genome that causes short tails.
......... there possibly might be..... or there might not.
I am unable to find evidence of either, all I know is that shepherd dogs were tail docked for centuries and shepard dogs were the first dogs found to inherit the gene mutation.
...this trait is now regularly selected by human intervention.
Corgis do not have the short tail because we would cut it off otherwise - they have short tail because we decide which dog breeds with which bitch.
Not forgetting that this gene only appeared around 1800’s and yes human intervention has influenced it in one or more ways.
Should 2 dogs carry this gene it is fatal to the off spring. Pups only survive if one parent only carries the gene.
Dogs exist because we humans are good at selecting breeding pairs that have a greater chance of reproducing preferred traits. there is no evidence of the genetic sequence being adapted within a single generation and thus allowing the inheritability of an acquired trait.
Dogs would survive and they do without human intervention also, but wild dogs do not have the bobtail gene.
- please note difference between acquired trait and inherited trait
All the genetic characteristics that make echochartruse look like echochartruse were inherited from your parents through a combination of your mothers and fathers genes. if your father had lost a leg in an accident this would not be inherited. every single one of the genes (barring genetic damage/random mutation) that you pass onto your children will have come from your parents.
No matter what traits you gain during your lifetime or changes to your bodily appearance - the genes you pass to your offspring will be those you received from your parents (again barring genetic damage/random mutation).
OK I understand
Why should we bar genetic damage /random mutation if you think this is the pathway to evolution,.. you obviously don’t. Is this correct?
This is Larmarckism - and there is no evidence to back it up. The article you quoted does NOT substantiate this claim in any way. Do you seriously believe; that given identical twins one of whom has lost a limb after an accident that the children of the 'amputee twin' will have different genetic inheritance than those of the 'non-amputee twin'?
Matthew
If Identical twins married identical twins would each set of twins have identical children? Somehow I don’t think so, There are life factors associated that influences individual life.
Rethinking The Genetic Theory Of Inheritance: Heritability May Not Be Limited To DNA
The CAMH study showed that epigenetic factors – acting independently from DNA – were more similar in monozygotic twins than dizygotic twins. This finding suggests that there is a secondary molecular mechanism of heredity. The epigenetic heritability may help explain currently unclear issues in human disease, such as the presence of a disease in only one monozygotic twin, the different susceptibility of males (e.g. to autism) and females (e.g. to lupus), significant fluctuations in the course of a disease (e.g. bipolar disorder, inflammatory bowel disease, multiple sclerosis), among numerous others.
It would be interesting for someone to study the length of foreskin in various group’s babies that practice circumcision and compare those who don’t. It would be very interesting for someone to research when exactly the Bobtail gene appeared and its history. To reseach why only shepard type dogs and dogs that were tail docked are more likely to have this gene.
The bobtail gene did not always exist and does not exist in some dog breeds at all. But I would be unwise to disregard that the preference in dog shows of the natural bobtail did not influence this genetic mutation.
Please read....... Epigenetics: DNA Isn’t Everything http://www.sciencedaily.com/releases/2009/04/090412081315.htm
Cell memory may be important here, what if a generation or two of dogs were tail docked and bred, the ones who didn’t get docked were sold as pets not breeders, the un docked tail dogs never bred, isn’t there a slight chance that cell memory played an important roll in this genetic mutation? That it only took one dog's genes to mutated to accommodated the bobtail which was then passed onto the next generation?
We just can't block our minds because we dont have the evidence, we should find the evidence for or against. Can anyone find evidence against this type of evolution?
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Epigenetic traits are aquired and can be inherited by the next generation.
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To precis - there is possibly a ancestral (naturally occurring) mutation to a part of the dog genome that causes short tails.
......... there possibly might be..... or there might not.
I am unable to find evidence of either, all I know is that shepherd dogs were tail docked for centuries and shepard dogs were the first dogs found to inherit the gene mutation.
So why make the enormous and illogical assumption that this is evidence of larmarkian evolution? We know the unit of inheritance now, and know that it wouldn't be altered by tail docking.
...this trait is now regularly selected by human intervention.
Corgis do not have the short tail because we would cut it off otherwise - they have short tail because we decide which dog breeds with which bitch.
Not forgetting that this gene only appeared around 1800’s and yes human intervention has influenced it in one or more ways.
Should 2 dogs carry this gene it is fatal to the off spring. Pups only survive if one parent only carries the gene.
So the breeder wouldn't make that mistake again.
Dogs exist because we humans are good at selecting breeding pairs that have a greater chance of reproducing preferred traits. there is no evidence of the genetic sequence being adapted within a single generation and thus allowing the inheritability of an acquired trait.
Dogs would survive and they do without human intervention also, but wild dogs do not have the bobtail gene.
Obviously - if the pups don't survive.
This is Larmarckism - and there is no evidence to back it up. The article you quoted does NOT substantiate this claim in any way. Do you seriously believe; that given identical twins one of whom has lost a limb after an accident that the children of the 'amputee twin' will have different genetic inheritance than those of the 'non-amputee twin'?
Matthew
If Identical twins married identical twins would each set of twins have identical children? Somehow I don’t think so, There are life factors associated that influences individual life.
Not to mention genetic recombination, and the fact that each child gets a shuffled assortment of genes from each parent. This argument doesn't help you.
Rethinking The Genetic Theory Of Inheritance: Heritability May Not Be Limited To DNA
The CAMH study showed that epigenetic factors – acting independently from DNA – were more similar in monozygotic twins than dizygotic twins. This finding suggests that there is a secondary molecular mechanism of heredity. The epigenetic heritability may help explain currently unclear issues in human disease, such as the presence of a disease in only one monozygotic twin, the different susceptibility of males (e.g. to autism) and females (e.g. to lupus), significant fluctuations in the course of a disease (e.g. bipolar disorder, inflammatory bowel disease, multiple sclerosis), among numerous others.
It would be interesting for someone to study the length of foreskin in various group’s babies that practice circumcision and compare those who don’t. It would be very interesting for someone to research when exactly the Bobtail gene appeared and its history. To reseach why only shepard type dogs and dogs that were tail docked are more likely to have this gene.
The bobtail gene did not always exist and does not exist in some dog breeds at all. But I would be unwise to disregard that the preference in dog shows of the natural bobtail did not influence this genetic mutation.
Please read....... Epigenetics: DNA Isn’t Everything http://www.sciencedaily.com/releases/2009/04/090412081315.htm
Cell memory may be important here, what if a generation or two of dogs were tail docked and bred, the ones who didn’t get docked were sold as pets not breeders, the un docked tail dogs never bred, isn’t there a slight chance that cell memory played an important roll in this genetic mutation? That it only took one dog's genes to mutated to accommodated the bobtail which was then passed onto the next generation?
Do dogs breed with their tails? If not, "cell memory" as you put it is irrelevant.
We just can't block our minds because we dont have the evidence, we should find the evidence for or against. Can anyone find evidence against this type of evolution?
We know that physical injury like this does not lead to changes in DNA of germ cells, so we already do know that this doesn't work.
You're right that there are some epigenetic factors that we need to look at (and environmental factors during pregnancy could well have an impact) - but it's never going to be as simple as your tail docking example.
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"We just can't block our minds because we dont have the evidence, we should find the evidence for or against. Can anyone find evidence against this type of evolution?"
Yes, and I mentioned it a while ago- Jewish baby boys are still born with foreskins even after many generations of their removal.
The only person "blocking their mind" here is you.
You are refusing to accept clear experimental evidence that Lamarckian evolution does not happen.
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Grandparents' access to food as young children influences disease in their progeny In other words, you are what your grandmother ate. But, wait, wouldn't that imply what every good biologist knows is practically scientific heresy: the Lamarckian inheritance of acquired characteristics?
Studies done on agouti mice indicate it is possible.
Epigentics is to do with acquired traits that can be inherited.
Biologists have proven that certain types of cellular information can be transmitted from one generation to the next, even as DNA sequences stay the same.
Especially for BenV,
I will say again............. there possibly might be..... or there might not.
I am unable to find evidence of either, all I know is that shepherd dogs were tail docked for centuries and Shepherd dogs were the first dogs recorded to inherit the gene mutation.
This gene is shared with other working dog breed's that were tailed docked to breed.
I am only trying to find proof one way or the other.
Unless there is proof one way or the other then it still remains a mystery why this gene is only found in breeds of dogs that for centuries had their tails physically docked.
Ben V’s statement - “Do dogs breed with their tails? If not, "cell memory" as you put it is irrelevant.”
Isn’t breeding about sharing genetics DNA whether it is bred naturally or in a test tube?
Can you explain your statement please.
‘Epigentics’ was spoken about in the 1800’s. Up until 20 odd years ago anyone speaking of epigenetic regulation was more or less an outcast. Until Andy Feinberg and Bert Vogelstein, both at Johns Hopkins University found the etiological link between epigenetic change and cancer.
Epigenetic regulates developmental genes during times of stress by releasing previously hidden or buffered phenotypic variation. This variation persisted in a heritable manner, generation after generation.
Couldn’t the gene mutation of shepherd, working dogs have happened due to the dogs that bred were always docked?
"Epigenetic has always been Lamarckian. Probably why science ignored it for so long.
It hasn’t been disproven or disproven.But worth a hugh governement grant after all, I imagine.
If the docked tailed dogs were the only ones to breed because of the breeder’s association’s standard. Then I would suggest that there is a good chance because of the stress placed on these working dogs their epigenome changed for survival.
The fact that if 2 dogs with this gene mate then fatality is high. But should the pup that survives mates then it could be like the mule, maybe.
Or is there a chance that the gene for long tail is lost forever. I don’t think that, I think genes get shuffled, not lost. All life has much the same DNA, it’s the information carried in the DNA that is important and how it is expressed.
I say nothing is impossible unless there is evidence and proof. I can’t find evidence for or against, its only other's opinions. Has there been any studies on bobtail genes in dogs that prove how it came about and its history?
Please show me the link.
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We know that physical injury like this does not lead to changes in DNA of germ cells, so we already do know that this doesn't work.
Ben V, can you prove or disprove... That Tasmanian Devils are genetically maturing earlier to be able to breed which may or may not allow them to pass on immunity to their offspring, has nothing to do with the fatal damage they are experiencing because of the cancer?
What is your thoughts here please?
We know DNA does not have to change!?
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You have had my thoughts on that issue before, why bring it up again?
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Echochatreuse,
I see you are still ignoring the evidence.
Here it is in bold letters.
Jewish baby boys are still born with foreskins even after many generations of their removal.
I presume you are going to ignore this again because it doesn't say what you want to hear.
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Echochatreuse,
I see you are still ignoring the evidence.
Here it is in bold letters.
Jewish baby boys are still born with foreskins even after many generations of their removal.
I presume you are going to ignore this again because it doesn't say what you want to hear.
Remembering that dogs with the bobtail gene are still born with tails, they are just varying lengths.
But has anyone done a study to find out if the human foreskin is shorter, whatever, different from generations of not removing it?
Shaving a beard off promotes growth.
What study has been done to prove that removing foreskin has an effect or not similar to the various tail lengths of the dogs with the bobtail gene? Or maybe it promotes growth like shaving a beared! I'd like to see some evidence.
by the way just becasue you write something in bold letters doesn't mean it is true or proves anything.
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"by the way just becasue you write something in bold letters doesn't mean it is true or proves anything."
No, but it stopped you ignoring it.
"Shaving a beard off promotes growth."
Not, so far as I'm aware in a man's sons, so it has no relevance to evolution.
"But has anyone done a study to find out if the human foreskin is shorter, whatever, different from generations of not removing it?"
Not as far as I know, but I'm sure there would be anecdotal evidence if there had been a change; have you heard of any?
If not you are just putting forward your hope rather than evidence.
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Epigenetic traits are aquired and can be inherited by the next generation.
Is there a gene for that?
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"But has anyone done a study to find out if the human foreskin is shorter, whatever, different from generations of not removing it?"
Not as far as I know, but I'm sure there would be anecdotal evidence if there had been a change; have you heard of any?
If not you are just putting forward your hope rather than evidence.
So I assume we are both asking the same question.
Can we be sure that forskin has not changed in any way over the thousands of years or even decades without really investigating, testing and proving it otherwise it is just personal opinion.
If dogs can develop a bobtail gene,
If shaving a beard will promote its growth,
who knows maybe circumcision over vast periods of time and throughout all the generations who are circumsided, maybe, just maybe there is a difference.
I cant find evidence for or against. I truly don't think that a study has been done.
Now I'm not saying that there hasn't been a study done, just that it is impossible to google.
I can not find anything written about it at all.
Can we say with knowledge and proof, that removing the foreskin at birth over many generations has not alter the foreskin or anything else in any way?
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Epigenetic traits are aquired and can be inherited by the next generation.
Is there a gene for that?
Many various genes.
If 'C-sections Births Cause Genetic Changes That May Increase Odds For Developing Diseases In Later Life' - then maybe, maybe not the next stressful situation the new born finds themself in (may or may not) effect genetic change.
http://www.sciencedaily.com/releases/2009/06/090629081443.htm
Diabetes and Asthma are 2 diseases which the genes can be inherited.
Remembering that change happens under stress.
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"But has anyone done a study to find out if the human foreskin is shorter, whatever, different from generations of not removing it?"
Not as far as I know, but I'm sure there would be anecdotal evidence if there had been a change; have you heard of any?
If not you are just putting forward your hope rather than evidence.
So I assume we are both asking the same question.
Can we be sure that forskin has not changed in any way over the thousands of years or even decades without really investigating, testing and proving it otherwise it is just personal opinion.
If dogs can develop a bobtail gene,
If shaving a beard will promote its growth,
who knows maybe circumcision over vast periods of time and throughout all the generations who are circumsided, maybe, just maybe there is a difference.
I cant find evidence for or against. I truly don't think that a study has been done.
Now I'm not saying that there hasn't been a study done, just that it is impossible to google.
I can not find anything written about it at all.
Can we say with knowledge and proof, that removing the foreskin at birth over many generations has not alter the foreskin or anything else in any way?
Considering that humans have been conducting this "experiment" for several thousand years already, it's inconceivable that no one would have detected a difference between the ethnic groups involved by now, if there was any.
You are arguing that these influences would result in rapid genetic changes. If it were to take several thousand years and many generations, it would hardly be considered rapid.
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In regard to males who experience circumcision compared to those who don't, what I am saying is that there is no evidence for or against change, no one has done any study to find out if there is or isn't any change so it is just an opinion that some have that there isn't any genetic or other change. Just an opinion, a guess.
In regard to Cesarean births there has been study to show that there is a genetic change eventuating from a Cesarean birth and that it is inheritable.
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In regard to males who experience circumcision compared to those who don't, what I am saying is that there is no evidence for or against change, no one has done any study to find out if there is or isn't any change so it is just an opinion that some have that there isn't any genetic or other change. Just an opinion, a guess.
LOL! No evidence! Is four thousand years of evidence that it has no effect insufficient?
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for Geezer, Do you deny rapid genetic change?
A well established theory in genetic evolution states that even after millions of years of evolution, homologous genes in closely related species, such as humans and chimps, are barely distinguishable from one another. That the human and chimp sperm genes were so radically different suggests exceedingly rapid evolution.
please read...Simulated climate change provokes rapid genetic change in the Mediterranean shrub Fumana thymifolia
http://www3.interscience.wiley.com/journal/119416704/abstract?CRETRY=1&SRETRY=0
Rapid Genetic Change in Terrestrial Plants
http://www.co2science.org/articles/V11/N25/EDIT.php
Rapid acceleration in human evolution described
http://www.reuters.com/article/idUSN1043228620071210
Read more: Genetic evidence for punctuated equilibrium - The Scientist - Magazine of the Life Sciences http://www.the-scientist.com/news/display/25023/#ixzz0rt72JQ6v
Rapid evolution on ecological time scales is now widely recognized in natural ecosystems
"Rapid change, contrary to previous opinion, really seems to be happening quite frequently in a number of locations around the world," Pergams said. "There seem to be significant correlations with 'people-caused' parameters, such as population density and anthropologically-caused climate change."
Environmental perturbations, on the other hand, can affect large fractions of a population and are thus more likely to play a significant role in genetic network evolution. This article will appear in the February 2005 issue of American Naturalist.
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for Geezer, Do you deny rapid genetic change?
No, I don't. All I'm saying is that the 4,000 year circumcision experiment has produced no genetic change.
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LOL! No evidence! Is four thousand years of evidence that it has no effect insufficient?
Length in the 102 who were circumcised was 0.8 cm (5% or 1/20th) less than length in the 43 who were uncircumcised.
The above relates to the size of penis for circumcised men.
I have just read a magazine here that states men are born with various size forskins and recently more babies are noted to be born with extra long forskin.
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for Geezer, Do you deny rapid genetic change?
No, I don't. All I'm saying is that the 4,000 year circumcision experiment has produced no genetic change.
you mean nothing has been found? or can you show evidence?
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As bobtail gene produces tails of various lengths in herding dogs. Human males are born with various lengths of foreskin, fact.
This is most probably relevant to a gene and it would be interesting to find out if circumcision has an influence.
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it would be interesting to find out if circumcision has an influence.
It doesn't. If it did, don't you think we wouldn't know about it after 4,000 years?
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This
"I have just read a magazine here that states men are born with various size forskins and recently more babies are noted to be born with extra long forskin."
is not consistent with any significant subset of the human race having a noticeably reduced foreskin for any reason, such as proposed lamarkian evolution among Jewish boys.
You have collected the evidence which proves that your idea is wrong.
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This
"I have just read a magazine here that states men are born with various size forskins and recently more babies are noted to be born with extra long forskin."
is not consistent with any significant subset of the human race having a noticeably reduced foreskin for any reason, such as proposed lamarkian evolution among Jewish boys.
You have collected the evidence which proves that your idea is wrong.
I am unable to find a scientific study for this exploring the genetic variation.
If you have evidence of such a study please let me know.
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I am unable to find a scientific study for this exploring the genetic variation.
If you have evidence of such a study please let me know.
There is probably a good reason you can't find any references. It might well be that there are none.
If you want to confirm your proposal of genetic change, the onus is on you to provide positive evidence that it exists. It really doesn't work the other way around.
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This
"I have just read a magazine here that states men are born with various size forskins and recently more babies are noted to be born with extra long forskin."
is not consistent with any significant subset of the human race having a noticeably reduced foreskin for any reason, such as proposed lamarkian evolution among Jewish boys.
You have collected the evidence which proves that your idea is wrong.
I am unable to find a scientific study for this exploring the genetic variation.
If you have evidence of such a study please let me know.
So, you accepted the magazine article as evidence when you thought it supported your belief, but once I showed that it proved you were wrong, it was no longer adequate.
It seems that you will go to considerable effort not to accept that you are wrong.
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I would just like to say that the quote below is not substantiated, there is no proof that having foreskin removed from generations of children has no genetic change or has genetic change. This statement is opinion only not fact.
It may seem odd to consider this idea "It is like saying that if I have a hand chopped off, and then have a child, the child is likely to be born with no hand." but, if Lamarckian evolution worked, Jewish boys would be born with no foreskin.
Again, what I am saying is that there is no evidence for or against genetic change as there seems to be no study done.
Although, there has been study done to show that the size of penis is smaller in children who's foreskin has been removed.
Just like the bobtail gene produces various lengths of tails in herding dogs, I have found that babies have various lenghts of foreskin, but human foreskin has not been associated with any scientific study. Only observation.
I have read in a magazine (not scientific)that in a specific hospital it had been noted that some babies had seemingly longer foreskin than previous generations. The nationality of the babies have not been mentioned or whether they come from generations of having the foreskin removed or not.
The flippant remark by Bored Chemist should not be taken as proof until proven.
I have just put forward the information that I have found. I am not saying it does or doesn't. Whether the foreskin is short medium or large or extra large, there seems be be no study done to determine why. So why did Bored Chemist make such a statement without being able to back it up?
If a Cesarean birth can alter genes in a baby that can then be inherited, isn't that acquired?
If we all have the same genetic code then a mutation happens, causes a cancer that can be inherited such as breast cancer, isn't that acquired?
If Tibetans can develop 10 new genes (or the epigenome unravels these genes) to allow them to breath at high altitudes and this is inheritable isn't this acquired?
Just as babies born is specific months in specific locations are more proned to specific disease, everything has an effect. This is proven.
In each case an individual had to have the genetic make up which they were not born with, Not inherited but acquired and is inheritable. Then there is a great possibility that generations of foreskin removal as a child will effect generations to come. There is No study into this and therefore we can not be sure it does or doesn't have effect.
AGAIN - I am not saying it does or doesn't effect the following generations but you say 'it doesn't' without proof.
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Dr. Art Petronis, head of the Krembil Family Epigenetics Laboratory at the Center for Addiction and Mental Health, has revealed new evidence that DNA may not be the only carrier of heritable information; a secondary molecular mechanism called epigenetics may also account for some inherited traits and diseases. These findings challenge the fundamental principles of genetics and inheritance, and potentially provide a new insight into the primary causes of human diseases. (Credit: Copyright Center for Addiction and Mental Health)
Epigenetics: 100 Reasons To Change The Way We Think About Genetics
'New evidence for epigenetic inheritance has profound implications for the study of evolution, Jablonka and Raz say.'
http://www.sciencedaily.com/releases/2009/05/090518111723.htm