RE: head sizes correlated to prey size?
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by pictigaster1 on December 23, 2009
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I do disagree on a bit of the post tho John.If a snake is eating large prey this could be a factor in the gene kicking in to create a large head where as a snake chain fed rats such as the pin head burms never had the gene kick in.I know for a fact that this has happened and have scene it many times when I kept pythons.I do believe that there are races with geneticly smaller or larger heads as well.In many snakes.I have a dwarf atrox a mountain form that will not grow large yet at the bottom of the mountain the big guys exist.This guy will never be over 3 foot ever.Genetics are not understood in many areas.Some genetic factors do not manifest unless the correct set of stimulus comes in to play .These sets of rules you speak of are true 99.9 percent of the time .I just do not think it is as simple as large prey makes big head in all snakes .It does have to be in the genes .I just do not think that all races can have a giant head they must have the predisposition.That does not mean they will.
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RE: head sizes correlated to prey size?
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by BobH on December 24, 2009
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I think John and Fred covered most of the bases here. Jaw size and gape has to have a genetic component. The important thing here is what the individual does during its life is does not enhance its DNA, although by it surviving and reproducing is does pass this to the next generation. If we all took up weight lifting we could see much bigger muscles (jaw size) but the idea that this would be passes to our kids is where it breaks down. So if we were to compare our muscle size to that of a group of weightlifters, the weight lifters would have larger muscles. So there is some credibility in wild caught "developing" larger jaws and gape.
Best wishes for the season
Bob
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RE: head sizes correlated to prey size?
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by Atrox788 on December 24, 2009
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As otheres have said, a single animal will not be able to make this adaptaion in one life time. Considering the size of these snakes and how they are known to take on huge prey as it is, I dont see any need for imporvement. An evolution trend however could occur in an isolated population. Chapple Island Tigersnakes have larger jaws compared to other island and main land forms to accomidate eating mutton bird chicks but they have been isolated for god knows how long on the island with no other means of food for adults. If there were a retic population that was isolated somwhere and they needed bigger jaws to exploite the avaible food source then yes, it is a possibility but otherwise, a retics a retic..
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RE: head sizes correlated to prey size?
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by theemojohnm on December 24, 2009
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Archie's points are duly noted. However, the only manner in which this can occur in is in the building of mussel, as Terry said, and the constant usage and stretching of tendons, much as body-builders build mussel.
As everyone has said, we have all seen certain individual animals with exceptionally large heads.
The difference between a "muscular head" and simply an exceptionally large head or small head, in proportion to the rest of the body, is genetic.
In some highly adaptive species (C. horridus), a breeding group of animals may be triggered by an environmental stimuli, that does trigger very low-level phenotypic variances in relatively few generations. Still however, depending on the genetics of the parents, and the parent’s parents, etc..
Such as is seen in ball pythons and squams.
Something as big as skeletal head structure is a pre-programmed, by what the species genetic blueprint is, and what environmental stimuli affect it over many generations.
I will never, no matter how many environmental stimuli I encounter in my lifetime, evolve into a Chinese man, no matter if I live to my max.
No, the majority of my physical development was, certainly, genetically pre-determined.
Good to see ya 'round Fred!
Take Care,
-John Mendrola.
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RE: head sizes correlated to prey size?
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by theemojohnm on December 24, 2009
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Right on Bob.
Through prolonged use of mussel, and "bending” to what may be the only available prey source in the area, wild-caught animals certainly do, for the most part, have more muscular jaws and heads.
But, the question was about a skull, correct?
A genetically encoded component as large as skeletal frame-size, is CERNTAINLY pre-determined, and is not altered over the course of a single animals life, over a single generation, no matter how much environmental stimuli that animal encounters throughout its life.
If that were the case, those crazy Amazonian Witchdoctors wouldn't have even had to KILL people to shrink heads. =)
Good to see everyone.
Just when I thought Facebook took over! LOL.
Merry Christmas.
Take Care,
-John Mendrola.
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RE: head sizes correlated to prey size?
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by stopgetinpopped on December 24, 2009
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Whoa, I can't even begin to understand how my information has been this misunderstood and extrapolated into....?
Let me clarify. Genetics are the building blocks of it all, obviously. No matter how much you feed a pygmy python, no matter what environmental stimuli is thrown it's way, it will never grow to be a retic.
However, if you collect two sibling retics from the wild. Leave one in it's environment and bring one home. Both survive for 10 years. The wild retic will have a head at least twice the size of the captive raised one. For the reasons I laid out in my earlier post. I have seen this, I have done this as have many many many keepers in the past. A retic is not just a retic. There are many controllable factors for adaptation within a snakes individual lifetime.
Same as if I were to quit smoking and go to the gym everyday weightlifting. My body, both muscle mass and skeletal system would adapt and grow to its perceived nescessity...in order to survive in the environment that it finds itself.
Make sense...?
A wild raised snake is much different than a captive raised snake...without question. Honestly it can't even be argued because it's that simple and straightforward....
Cheers!
T-
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RE: head sizes correlated to prey size?
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by theemojohnm on December 24, 2009
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No, I interpreted your post correct Terry.
You are correct. Of course, this does happen, within a small gap in a determined genetic blueprint.
The original question was about a skull. You will not see any noticeable skull variation in a single animal throughout its lifetime that is not already going to become more pronounced to begin with. Hence, genetically pre-determined.
Skeletal structure will not be affected. Mussel mass, tendon strength, and flexibility, absolutely.
Possible, sure. But not in one animals lifetime.
Take Care,
-John Mendrola.
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RE: head sizes correlated to prey size?
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by pictigaster1 on December 24, 2009
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I do not know John our favorite singer Mike jackson became white in a few short years...LOL
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RE: head sizes correlated to prey size?
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by pictigaster1 on December 24, 2009
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Oh, said stimuli captivity versus wild.These are stimuli that will affect genetic predisposition.I also think your post was well understood by all.It was in fact a good post.You also explained your self rather well.Question will a super dwarf be a giant ..Answer no but it will grow to 16 feet not 22 in the wild.Captive specimens are not fed enough to do this most of the time,The reason is money the smaller the adult the more money you can charge for offspring.Mans attempt to play god for monitary gain....
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RE: head sizes correlated to prey size?
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by BobH on December 24, 2009
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John M- I do think you have under estimated the dynamic qualities of boney tissue. It does respond to applied stresses just like muscle and connective tissue.
Bob H
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