What makes a GIANT??

[M_surinamensis]

I tend to disagree with some of the posts. A giant line originates from an ancestor that was essentially just a large Leo.

Does it now?

Genetics, the specific genetic combinations found in every individual animal, represent both absolutes and potentials, detailing every aspect of the resulting organism.

Most genotypical change seen within a species is a result of a slow, multi-generational process where tendencies and similarities are reproduced and reinforced; either as a consequence of the extremely complex and sometimes contradictory pressures of natural selection in the wild, or as a result of selective breeding towards a predicted outcome orchestrated by human owners in captivity.

Some genotypical changes are a result of mutation. The initially spontaneous* change in an individual which enjoys reproductive success is duplicated and spread.

Looking at individual traits independent of one another is... a myopic approach. It's a little like trying to paint a landscape while viewing the panorama of reality through a cardboard tube. I'm about to do it anyway though.

There's a difference between a giant and A Giant™ leopard gecko.

A Giant™ is, as far as it is understood, a result of a specific and reproducible genetic mutation which manifests as an absolute according to its method of transmission. It is not a tendency, it is not a gradual shift brought about by selective breeding of animals sharing a position on the bell curve of genetics, it's a definite and specific genetic abnormality which manifests immediately to its full potential in animals carrying the responsible gene. This is a very different type of expression and method of transmission than is the case when dealing with animals which have simply been line bred for size.

There are three difficulties when it comes to the public understanding of this.

The first is that too many people slept through their eighth grade biology class and wouldn't understand Mendelian genetics if it came up and bit them in the face. So a lot of people spread a lot of misinformation a lot of the time, making it difficult to disseminate accurate and thorough information.

The second is that there can potentially be multiple and distinct causes for something that is displayed. A big gecko can be the result of mutation, of line breeding and of multiple environmental factors (malformed glands causing overgrowth, an overabundance of nutrients which cause abnormal growth, exposure to... well... steroids from an external source). Dozens of causes, manifesting in similar enough effects that they are difficult to distinguish using casual observation.

The third is that the mutation was marketed using a descriptive term. "Giant" is a word, with a definition, that people use anytime it is appropriate. In the same sense that a stripe is a stripe or that yellow is a color. "Of great size" says nothing about why that great size exists, what caused it, what is happening inside the animal which made it that big. So "a giant" and a genetic "Giant™" are distinct, but that distinction is lost due to language confusion. It happens all too often in the marketing used to advertise and sell herps, specific genetic mutations are given generic (but appealing) labels which do not distinguish the condition from other causes for similar appearances. Not an easily solved problem though, since the other options also have pitfalls... saying "Tremper line genetic giant" is awkward from a conversational standpoint and less directly descriptive terms only allow communication between people who have a common vocabulary**

So... a giant line is not necessarily the offspring of "just a large leo" and those who choose to work with or sell giants have an obligation to communicate the origins of their animals to their potential customers. Since selling the offspring of "just a large leo" to a public which widely recognizes the word "giant" to be a specific genotype borders on fraudulent.


*not really spontaneous in most cases, but unexplained to a degree that it appears spontaneous to observers.

**"eclipse" and "caramel" are nearly meaningless, except for the meaning we all agree to acknowledge. Then there are things like "mojave" for ball pythons, which, once in awhile, some people who don't know any better mistake for a locale.

 

[bluenosebully6]

See now pink understands my point. Where did the GIANT come from? It's not a mutation its a genetically inherited trait NOT A MUTATION or result of abnormal glands in most cases. I know we r talking about herps here but let's venture back into human territory for a moment... people who have the genetic mutation that causes giantism and dwarfism are commonly marked by scores of other ailments associated with the mutation such as skeletal structure problems ie elongated or shortened appendage respectively, brittle bones poor circulation, calcium and iron deficiencies resulting in broken, deformed, or overgrown bones and skeletal structures a lot of the time resulting in premature death. But in these GIANTS be it a line.breed or a wild for instances if itmeets the weight and length requirements seem to be in perfect health without deformities commonly associated with such mutations or diseases. I'm no doctor but with all the information available this far on these GIANTS my hypotheses would have to ratify my previous statement that the giant gene is an inherited trait NOT A MUTATION. And it most certainly occurs in leos with no line breed genetics. U can breed for color pattern and what have u but u cannot change the genome of a Leo. Sorry to break it to u but There's not some giant subspecies of leopard gecko.

 

[lillith]

As has been stated, there are two types of giants, one is a genetic mutation, and one is a linebred trait. Both are inheritable traits, with different methods of inheritance from the parents involved.

REALLY. Two different processes at work here. Not kidding.

 

[M_surinamensis]

I'm no doctor but with all the information available this far on these GIANTS my hypotheses would have to ratify my previous statement that the giant gene is an inherited trait NOT A MUTATION. And it most certainly occurs in leos with no line breed genetics. U can breed for color pattern and what have u but u cannot change the genome of a Leo. Sorry to break it to u but There's not some giant subspecies of leopard gecko.

"You keep using that word. I don't think it means what you think it means." -Mandy Patinkin, as Inigo Montoya

Anyone else ever write a post and then subsequently get the feeling that they shouldn't have bothered as they read the reply? Maybe I just need to learn to type faster, that one this morning took me an hour. I probably could have done something pretty productive in that hour, rather than wasting it to write something that would be misunderstood, ignored and refuted with lolspeak by the person it was intended to help.

 

[bluenosebully6]

Ok maybe I'm being misunderstood.....let's try this again....what I'm saying is this: the selectively linebred giants are the same as a wild caught or owned by somebody who has not linebred two giants to ensure large offspring. There are naturally occurring giants. No two leos are the same. Some are smaller some are larger. Just like there are naturally occurring albinos in the wild. What we are doing is selectively breeding the leos who tip the scales at the high end of the spectrum with each other to ensure larger offspring. I breed bluenose pitbulls and the same rules apply there. Everybody is entitled to believe what they want but some of u are putting up the false impression that what ur saying is scientific fact. I don't have a phd in biology but I speak on what things I know and what is more than obvious. I'm speaking so vehemently on this because I have a sht male that is 9 1/2 inches and well over 100 grams. If u were to put my guy next to a selectively linebred giant of the same size are u gonna say that mine is.not a giant.because he hasn't been linebres by a well known big name breeder.....cmon here

 

[lillith]

You are right about linebreds, blue, but you are wrong that there isn't a co-dominant inheritable genetic variant as well.

In my opinion, we ought to call them two different things by trade.
Maybe call the linebreds "Jumbo" instead or something.

 

[Dragoon Gecko]

I can only agree with Ray:
Once you hold a giant and supergiant in your own hand, you will notice that they are different not only in size and weight, but also in body proportions and behaviour. Most Giant and Supergiants are much more calmer as normal geckos.

Head, Neck, Tail and body: Their whole aprrearance is more lanky as normal leopardgeckos.

I just had the best example of the Giant- Genetics yesterday:

I got a Trio of geckos last year from a friend of mine. They all were from a crossing Giant Raptor (Ron Tremper) x normal.


When I got them, they were approx. 8-9 months old, still growing and the females already pregnant. I raised them up, and soon wondered how big 2 of them grew despite the fact that all of them were bred so early.

When they turned 2 years I checked back with Ron if I was seeing things or not, and he approved that in deed the 2 bigger ones are Giants.

You can see them here for comparison:
http://geckoforums.net/showthread.php?t=76339

I know those pics aren't the best, but if you look carefully you can see that the Giant female has a longer neck than the normal female. Also, when the Giant female stays "straight", she looks much more like the Supergiant female than the normal female.

Keep in mind that the Giant and the normal female are sibling sisters: They were raised under the same conditions, and both were bred at the same time..

/Rebecca