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Is this an example of De-evolution?


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https://phys.org/news/2018-06-species-predators-isolation.html

Species found to lose fear of predators after 13 generations of protective isolation:

A trio of researchers from the University of Melbourne and the University of Life Science, Sydney, has found an isolated mammal species that lost its fear of predators in just 13 generations. In their paper published in the journal Biology Letters, Chris Jolly, Jonathan Webb and Ben Phillips describe their study of protected northern quolls living in Australia and what they found.

As humans encroach on territory occupied by other species, those other species lose out. Often, the result is endangerment or extinction. That has been the case for northern quolls, which once inhabited large parts of northern Australia. After humans arrived, their numbers declined sharply due mostly to the introduction of invasive cane toads. To prevent their extinction, environmentalists captured several of them and released them on two small islands off the coast of Australia. That effort, it seemed, was a remarkable success as quoll populations soon soared on the islands. Pleased with their results, environmentalist tried to capitalize on their success by capturing a large number of the creatures and placing them back in their native environment. Unfortunately, the experiment did not go as planned. Over the span of just 21 months, most of the quolls were gone. This time, it was not poisonous toads causing their deaths, it was dingoes capturing and eating them. This came as a surprise to the team, because prior to the arrival of humans, quolls were able to survive in territory occupied by dingoes. They did so, the researchers note, by hiding from them.

Read more at: https://phys.org/news/2018-06-species-predators-isolation.html#jCp

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the paper:

 

DOI: 10.1098/rsbl.2018.0222

Abstract: 
When imperilled by a threatening process, the choice is often made to conserve threatened species on offshore islands that typically lack the full suite of mainland predators. While keeping the species extant, this releases the conserved population from predator-driven natural selection. Antipredator traits are no longer maintained by natural selection and may be lost. It is implicitly assumed that such trait loss will happen slowly, but there are few empirical tests. In Australia, northern quolls (Dasyurus hallucatus) were moved onto a predator-free offshore island in 2003 to protect the species from the arrival of invasive cane toads on the mainland. We compared the antipredator behaviours of wild-caught quolls from the predator-rich mainland with those from this predator-free island. We compared the responses of both wild-caught animals and their captive-born offspring, to olfactory cues of two of their major predators (feral cats and dingoes). Wild-caught, mainland quolls recognized and avoided predator scents, as did their captive-born offspring. Island quolls, isolated from these predators for only 13 generations, showed no recognition or aversion to these predators. This study suggests that predator aversion behaviours can be lost very rapidly, and that this may make a population unsuitable for reintroduction to a predator-rich mainland.



Read more at: https://phys.org/news/2018-06-species-predators-isolation.html#jCp

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For your information on Cane Toads:

https://en.wikipedia.org/wiki/Cane_toads_in_Australia

extract:

Native to South and mainland Middle America, cane toads were introduced to Australia from Hawaii in June 1935 by the Bureau of Sugar Experiment Stations, now the Sugar Research Australia, in an attempt to control the native grey-backed cane beetle (Dermolepida albohirtum) and Frenchi beetle (Lepidiota frenchi).[3]These beetles are native to Australia and they are detrimental to sugar cane crops, which are a major source of income for Australia. Adult cane beetles eat the crop's leaves, but the main problem is the larvae, which feed on the roots. Adult cane beetles have a heavy exoskeleton and their eggs and larva are often buried underground, making them difficult to exterminate. Furthermore, conventional methods of pest control, such as pesticide use, would eradicate harmless species of insects as well, making it an unsatisfactory method.[4] Cane toads were to replace the use of pesticides like arsenic, pitch and copper. The success of using the moth Cactoblastis cactorum in controlling prickly pears in Australia also contributed to hopes for the cane toad.[5]

The cane toads bred immediately in captivity, and by August 1935 more than 102 young toads were released in areas around Cairns, Gordonvale and Innisfail in northern Queensland. More toads were released around Ingham, Ayr, Mackay and Bundaberg. Releases were temporarily limited because of environmental concerns but resumed in other areas after September 1936. Since their release, toads have rapidly multiplied in population and now number over 200 million and have been known to spread diseases affecting local biodiversity.[6]Unfortunately, the introduction of the toads has not only caused large environmental detriment, but there is no evidence that they have affected the cane beetles they were introduced to predate. The toads have steadily expanded their range through Queensland, reaching the border with New South Wales in 1978 and the Northern Territory in 1984. The toads on the western frontier of their advance have evolved larger legs;[7] this is thought to be related to their ability to travel farther. As a consequence of their longer legs, larger bodies, and faster movement, about 10% of the leading edge cane toads have also developed arthritis.[8] It was estimated that cane toads migrate at an average of 40 kilometres (25 miles) per year as of 1994,[9] but new research in 2014 indicated that the migration rate had increased to 60 km per year on the western front.[10]

220px-Bufoinvasion.gif

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My question of course is in the heading. With regards to the Quolls being released on the mainland. Is this evolution in reverse?

 

Edited by beecee
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38 minutes ago, beecee said:

My question of course is in the heading. With regards to the Quolls being released on the mainland. Is this evolution in reverse?

    No, this not an example of "De-evolution", nor is this "evolution in reverse".

    By reading the abstract of the paper that you posted, it would seem that it has nothing to do with evolution or "De-evolution".

    As the trio of researchers from the University of Melbourne and the University of Life Science, Sydney, has found , it suggests or seems to be due simply to the newly learned or "rapidly" forgotten "predator aversion behaviour" .

    To quote from the above extract : "This study suggests that predator aversion behaviours can be lost very rapidly, and that this may make a population unsuitable for reintroduction to a predator-rich mainland."

    For 13 generations there was no reason for the young to be taught or to learn to be averse to Dingoes, simply because there were no Dingoes on the two small islands off the coast of Australia where the 13 generations lived and bred.

 

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4 hours ago, et pet said:

    No, this not an example of "De-evolution", nor is this "evolution in reverse".

    By reading the abstract of the paper that you posted, it would seem that it has nothing to do with evolution or "De-evolution".

    As the trio of researchers from the University of Melbourne and the University of Life Science, Sydney, has found , it suggests or seems to be due simply to the newly learned or "rapidly" forgotten "predator aversion behaviour" .

    To quote from the above extract : "This study suggests that predator aversion behaviours can be lost very rapidly, and that this may make a population unsuitable for reintroduction to a predator-rich mainland."

    For 13 generations there was no reason for the young to be taught or to learn to be averse to Dingoes, simply because there were no Dingoes on the two small islands off the coast of Australia where the 13 generations lived and bred.

 

Interesting certainly and you have made a good point. But can this  "forgotten" predator aversion behaviour" be just a small step on the evolutionary scale? I mean the young of many animals are born with an inherent fear of known predators.  Your quote seems to suggest that anyway.....

Quote

"This study suggests that predator aversion behaviours can be lost very rapidly, and that this may make a population unsuitable for reintroduction to a predator-rich mainland."

But thanks for the answer anyway...:) I'll think about it. Nice to see you still around.:)

Edited by beecee
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The quote literally suggests that in this single isolated mammal species of northern quolls, predator aversion behaviours can be lost very rapidly.

There is nothing in the quote about the young of many animals being born with an inherent fear of known predators. 

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59 minutes ago, et pet said:

The quote literally suggests that in this single isolated mammal species of northern quolls, predator aversion behaviours can be lost very rapidly.

That's why I asked the question. Many animals are born with an inherent fear of known predators. Perhaps after 13 generations that possible inbred fear is bred out. 

Quote

There is nothing in the quote about the young of many animals being born with an inherent fear of known predators. 

Hmm, I'm not so sure. Lost? Bred out? 

"This study suggests that predator aversion behaviours can be lost very rapidly, and that this may make a population unsuitable for reintroduction to a predator-rich mainland."

Edited by beecee
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7 hours ago, et pet said:

No, this not an example of "De-evolution", nor is this "evolution in reverse".

    By reading the abstract of the paper that you posted, it would seem that it has nothing to do with evolution or "De-evolution".

I'm not sure. It does say, for example, "Antipredator traits are no longer maintained by natural selection and may be lost."

So their assumption is that the traits are due to evolution and are lost by evolution. If this is the case then this is still NOT an example of "de-evolution" or "reverse evolution". It would just be an example of evolution: there are costs to maintaining the aversion and so if there is nothing to select them, then they will be lost.

However, it is not clear if they ave actually confirmed that the traits are lost because of evolution or because the young are no longer trained to be averse. 

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2 hours ago, Strange said:

I'm not sure. It does say, for example, "Antipredator traits are no longer maintained by natural selection and may be lost."

So their assumption is that the traits are due to evolution and are lost by evolution. If this is the case then this is still NOT an example of "de-evolution" or "reverse evolution". It would just be an example of evolution: there are costs to maintaining the aversion and so if there is nothing to select them, then they will be lost.

However, it is not clear if they ave actually confirmed that the traits are lost because of evolution or because the young are no longer trained to be averse. 

Thanks Strange, not exactly my expertise [if I have any that is :P] but you have given some food for thought.

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6 hours ago, beecee said:

Many animals are born with an inherent fear of known predators.

Citation requested, please?

The idea that many animals are born with an inherent fear of known predators seems like something advanced by the Lamarckian Theory of Evolution, or the Theory of Inheritance of Acquired Characteristics.

Wasn't Lamarcks theory rejected because it was found that it is not possible for an acquired or learned behaviour to change  an individual's genes?

Edited by et pet
clarification
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7 minutes ago, et pet said:

Citation requested, please?

I am pretty sure that animals are born with 'instincts'. I have never seen a citation for that - it something we learn at school and from watching wildlife programs. Rabbits are known to be skittish of shadows and things that move fast over their heads...  this is to avoid being eaten by hawks and things....  do they learn this or is it instinctive? I am pretty sure they do not go to rabbit school where they all learn the names and shapes of the shadows of predator birds....  I think they are born with a genetic instinct that most prey animals have.... horses will skit at virtually anything...   paper bag blowing in the wind? Your horse will either ignore it or jump sky high  -  they are naturally skittish from being prey animals in the wild. Do I have a citation?...  no, sorry. Could I be wrong? - of course I could, but I am just repeating things I have learnt from years of school and watching nature programs, not reading wildlife study publications.

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54 minutes ago, et pet said:

Citation requested, please?

The idea that many animals are born with an inherent fear of known predators seems like something advanced by the Lamarckian Theory of Evolution, or the Theory of Inheritance of Acquired Characteristics.

Wasn't Lamarcks theory rejected because it was found that it is not possible for an acquired or learned behaviour to change  an individual's genes?

I'm not sure why you think this is so implausible. Far more complex behaviours are inherited. Evolving the ability to avoid predators would clearly be advantageous and therefore selected for. 

However, it looks like there is (as is often the case) both an inherited and an environmental component. They have evolved the ability to learn fear of predators but need exposure/training to actually express this behaviour.

https://www.reuters.com/article/us-predators-study/fear-of-predators-is-not-naturalstudy-idUSN2136840820070621

https://pdfs.semanticscholar.org/bd96/173020c76cdc78fbab30f70a89aa93aeac15.pdf

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5 minutes ago, swansont said:

Not really any such thing as de-evolution. Evolution is change. The "opposite" of change is not change, it is stasis.

Precisely. Anything else implies a directionality that does not exist in evolution.

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2 hours ago, Strange said:

I'm not sure why you think this is so implausible. Far more complex behaviours are inherited. Evolving the ability to avoid predators would clearly be advantageous and therefore selected for. 

However, it looks like there is (as is often the case) both an inherited and an environmental component. They have evolved the ability to learn fear of predators but need exposure/training to actually express this behaviour.

Implausible? I never stated, claimed, nor implied that I 'think this is so implausible'.

I merely asked for cited supporting evidence for the stated claim that : "Many animals are born with an inherent fear of known predators." 

Many of the Posters on this Site, and even those Posting in this Thread, have repeatedly stated that "claims require evidence".

Strange, is it incorrect that Lamarcks theory was rejected because it was found that it is not possible for an acquired or learned behaviour to change  an individual's genes?

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9 minutes ago, et pet said:

Implausible? I never stated, claimed, nor implied that I 'think this is so implausible'.

I merely asked for cited supporting evidence for the stated claim that : "Many animals are born with an inherent fear of known predators." 

Many of the Posters on this Site, and even those Posting in this Thread, have repeatedly stated that "claims require evidence".

Strange, is it incorrect that Lamarcks theory was rejected because it was found that it is not possible for an acquired or learned behaviour to change  an individual's genes?

Quote

Epigenetic mechanisms underlying learning and the inheritance of learned behaviors

Abstract
Gene expression and regulation is an important sculptor of the behavior of organisms. Epigenetic mechanisms regulate gene expression not by altering the genetic alphabet but rather by the addition of chemical modifications to proteins associated with the alphabet or of methyl marks to the alphabet itself. Being dynamic, epigenetic mechanisms of gene regulation serve as an important bridge between environmental stimuli and genotype. In this review, we outline epigenetic mechanisms by which gene expression is regulated in animals and humans. Using fear learning as a framework, we then delineate how such mechanisms underlie learning and stress responsiveness. Finally, we discuss how epigenetic mechanisms might inform us about the transgenerational inheritance of behavioral traits that are being increasingly reported.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4323865/

 

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3 hours ago, swansont said:

Not really any such thing as de-evolution. Evolution is change. The "opposite" of change is not change, it is stasis.

Bingo! The notion of devolution implies evolution is progressive and always moves towards some relative version of better. 

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40 minutes ago, StringJunky said:

Epigenetic mechanisms underlying learning and the inheritance of learned behaviors

Abstract
Gene expression and regulation is an important sculptor of the behavior of organisms. Epigenetic mechanisms regulate gene expression not by altering the genetic alphabet but rather by the addition of chemical modifications to proteins associated with the alphabet or of methyl marks to the alphabet itself. Being dynamic, epigenetic mechanisms of gene regulation serve as an important bridge between environmental stimuli and genotype. In this review, we outline epigenetic mechanisms by which gene expression is regulated in animals and humans. Using fear learning as a framework, we then delineate how such mechanisms underlie learning and stress responsiveness. Finally, we discuss how epigenetic mechanisms might inform us about the transgenerational inheritance of behavioral traits that are being increasingly reported.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4323865/

  StringJunky, the following is quoted from your supplied Link :  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4323865/ 

              " Conclusions

Within the last decade, the field of epigenetic regulation of gene function has gained great momentum. Remarkably, on the cusp of an era in which genetics was beginning to finally feel ‘finite’ through the successful sequencing of large mammalian genomes, an entire new era of gene regulation has stepped in, potentially making the workings of genome regulation exponentially more complex than was previously appreciated.

Additionally, our understanding of the neural basis of memory formation has paralleled this epigenetic revolution, and seemingly every mechanism of previously ‘understood’ synaptic plasticity and neural genetic organization also has a new chapter related to epigenetics to be explored. Even more surprisingly, the newfound understanding of epigenetic modulation has reopened the possibility of transgenerational inheritance of acquired traits through the process of epigenetic marking in gametes – an exciting but at times overwhelming and certainly controversial idea (Box 2). Prior examples already exist to demonstrate that behavioral traits may be inherited from ancestral populations. However, nuanced behavioral paradigms and sophisticated reductionistic techniques are paving the way to definitively address the matter of transgenerational inheritance of behavioral traits (85) (see Box: Outstanding Questions)."

   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4323865/ 

 

   Confucius never said : "Man who wears both Suspenders and a Belt lacks confidence."

Edited by et pet
Humour
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30 minutes ago, StringJunky said:

Evolution is like acceleration in physics: it doesn't matter whether it's speeding up or slowing down, it's still acceleration. Evolution is any change in allele frequency.

I was thinking of that example, but since acceleration is a vector, deceleration at least has a tenuous grasp on physical meaning.

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6 minutes ago, swansont said:

I was thinking of that example, but since acceleration is a vector, deceleration at least has a tenuous grasp on physical meaning.

But you don't use deceleration as physicist, do you? I know people use it in everyday life.

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12 minutes ago, et pet said:

  StringJunky, the following is quoted from your supplied Link :  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4323865/ 

              " Conclusions

Within the last decade, the field of epigenetic regulation of gene function has gained great momentum. Remarkably, on the cusp of an era in which genetics was beginning to finally feel ‘finite’ through the successful sequencing of large mammalian genomes, an entire new era of gene regulation has stepped in, potentially making the workings of genome regulation exponentially more complex than was previously appreciated.

Additionally, our understanding of the neural basis of memory formation has paralleled this epigenetic revolution, and seemingly every mechanism of previously ‘understood’ synaptic plasticity and neural genetic organization also has a new chapter related to epigenetics to be explored. Even more surprisingly, the newfound understanding of epigenetic modulation has reopened the possibility of transgenerational inheritance of acquired traits through the process of epigenetic marking in gametes – an exciting but at times overwhelming and certainly controversial idea (Box 2). Prior examples already exist to demonstrate that behavioral traits may be inherited from ancestral populations. However, nuanced behavioral paradigms and sophisticated reductionistic techniques are paving the way to definitively address the matter of transgenerational inheritance of behavioral traits (85) (see Box: Outstanding Questions)."

   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4323865/ 

 

   Confucius never said : "Man who wears both Suspenders and a Belt lacks confidence."

You  asked for evidence and I have provided a link for it...which is a discussion paper.  It's not definitive but it's there with other ideas. 

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1 hour ago, et pet said:

Strange, is it incorrect that Lamarcks theory was rejected because it was found that it is not possible for an acquired or learned behaviour to change  an individual's genes?

Yes. But I don't know that is relevant. No one is claiming Lamarckian inheritance. You were the one who brought it up, apparently as a straw man argument.

(Although, we know that experiences during an organisms lifetime can affect gene expression in at least the next generation. So maybe he wasn't completely wrong....)

 

7 minutes ago, StringJunky said:

You  asked for evidence and I have provided a link for it...

And I provided two. Which were ignored. Bu there you go.

Edited by Strange
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17 minutes ago, Strange said:

Yes. But I don't know that is relevant. No one is claiming Lamarckian inheritance. You were the one who brought it up, apparently as a straw man argument.

(Although, we know that experiences during an organisms lifetime can affect gene expression in at least the next generation. So maybe he wasn't completely wrong....)

 

And I provided two. Which were ignored. Bu there you go.

   beecee plainly and clearly stated or claimed : " Many animals are born with an inherent fear of known predators."  

   His statement or claim was "are born with", not are taught fear of known predators soon after being born, or learn the fear of known predators quickly after being born, but "are born with an inherent fear of known predators."

   This seems to coincide with Lamarcks beliefs. : http://necsi.edu/projects/evolution/lamarck/lamarck/lamarck_lamarck.html 

     " Lamarck is best known for his Theory of Inheritance of Acquired Characteristics, first presented in 1801 (Darwin's first book dealing with natural selection was published in 1859): If an organism changes during life in order to adapt to its environment, those changes are passed on to its offspring. "

   It was NOT "brought up" as, and still is NOT a straw man argument.

   The two Links you provided were NOT ignored - they were simply not supportive of beecee's claim that : " Many animals are born with an inherent fear of known predators."

    Your first provided Link : https://www.reuters.com/article/us-predators-study/fear-of-predators-is-not-naturalstudy-idUSN2136840820070621 , starts with the following : 

   " DALLAS (Reuters) - Fear of predators is not instinctive but is a learned behavior that only develops when prey species share space with animals that eat them, according to a new study released this week.

   The study’s conclusion: remove the lions, and the zebras will lose their fear of them. But add wolves to a new territory and the resident elk or moose will soon learn they spell trouble."

    The above quoted is clearly stating the opposite of what beecee posted.

   Your second provided Link : https://pdfs.semanticscholar.org/bd96/173020c76cdc78fbab30f70a89aa93aeac15.pdf , begins similarly :

   " Predator recognition is often dependent upon experience. This behavioural plasticity can potentially be exploited to enhance the antipredator behaviour of captive-bred animals, but it is first necessary to understand the specificity of learning.

   That Linked Paper also includes : "Although it may seem counterintuitive for antipredator skills to be dependent upon experience, the ability to learn about previously unfamiliar predators has been demonstrated in a wide range of taxa including fish, birds and primates (reviewed by Griffin et al. 2000)."

    and : "The question of how readily animals learn about predators is also important from an applied perspective. Reintroduced and translocated individuals are particularly vulnerable to predation after release, which has reduced the success of conservation programmes (MacMillan 1990; Beck et al. 1994; Wolf et al. 1996)."

   Strange, again, both of those Linked articles seem to re-enforce the notion that "aversion to predators" is a taught or learned "behaviour", which, again, would seem to offer NO SUPPORT to beecee's statement or claim : " Many animals are born with an inherent fear of known predators."

   So on to : Strange, did you respond to my question : is it incorrect that Lamarcks theory was rejected because it was found that it is not possible for an acquired or learned behaviour to change  an individual's genes? , with a Yes?

  If so, and if I am incorrect, Strange, why was Lamarcks theory rejected?

  Or is Lamarcks theory accepted? Is it possible for an acquired or learned behaviour to change an individuals genes?

    

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6 hours ago, et pet said:

Citation requested, please?

 

https://www.sciencealert.com/deep-unshakeable-fear-spiders-no-random-quirk-fate-born-arachnophobia

https://www.livescience.com/9808-fear-spiders-develop-birth.html

https://phys.org/news/2015-04-human-spiders-scientific-focus.html

At worst it appears that any inherent fear is debatable.

2 hours ago, et pet said:

Implausible? I never stated, claimed, nor implied that I 'think this is so implausible'.

I merely asked for cited supporting evidence for the stated claim that : "Many animals are born with an inherent fear of known predators." 

 I would suggest that asking for a citation may mean that you find the statement doubtful or questionable at best, wouldn't you agree?

 

1 hour ago, StringJunky said:

You  asked for evidence and I have provided a link for it...which is a discussion paper.  It's not definitive but it's there with other ideas. 

Yep certainly and thanks for the info.

2 hours ago, StringJunky said:

Evolution is like acceleration in physics: it doesn't matter whether it's speeding up or slowing down, it's still acceleration. Evolution is any change in allele frequency.

I had only heard of the phenomenon called de-evolution, which is why I asked the question in the first place. I certainly accept the view of yourself and others..something I have learnt today gladly. :)

 

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39 minutes ago, et pet said:

Strange, did you respond to my question

Yes.

39 minutes ago, et pet said:

The two Links you provided were NOT ignored - they were simply not supportive of beecee's claim

I didn't say they were.

40 minutes ago, et pet said:

Is it possible for an acquired or learned behaviour to change an individuals genes?

Surprisingly, yes. Well, the expression of those genes, anyway.

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