Matt Vanilla Gorilla
Chameleon Enthusiast
Thank you! You explained it very well!!!From the biologist's point of view: Inbreeding and line breeding (in any animal or plant species as well as in humans) results in the formation of a large number of homozygote allels or, to put it in simpler terms, in genes and chromosomes (components of the DNA) which get the same genetic information from the father as they get from the mother. For more detailed scientific information see https://en.wikipedia.org/wiki/Inbreeding or https://en.wikipedia.org/wiki/Dominance_(genetics) - and trust me, the principles are exactly the same for every species, including your particular breed of chameleon.
The results, in simple terms, are that all genetic defects which may be dormant in your adults, will "awaken" and actively show up in your babies. These will be mainly sicklish traits which will cause many of the babies to die naturally or have to be culled as they will be deformed or otherwise sick or debilitated. That is the downside. However, there are also some otherwise passive (scientifically called "recessive") genes which carry desired traits, such as a new colour or other desired physical feature. This feature will then be present visibly in some of the new babies. If you mate two babies who both visibly have such a desired feature, then ALL the resulting babies will have this desired feature, too, and it will remain visible and active in all the future generations, too. That's the upside. The downside is that it will take many generations to come to, while maintaining the one desired new feature, you will have stillborns and will have to cull some babies in every clutch and put effort into breeding out all the many undesired sicklish ones, which can take many years.
How can this be avoided? Only through collaboration of many breeders as it is, for example, common within purebred cat and dog breeder associations.
Let me explain this on the example of the White Swiss Shepherd Dog (which I used to breed in former times). This breed resulted from the old-style German Shepherd Dog, which is, as we all know, black and sable, without inbreeding and with no other dog breed having ever bred in. This is because the colour white has always been genetically "hidden" in many German Shepherds and occasionally a breedeer would get a white puppy from healthy, ethical breeding with genetically unrelated parents. The breeders used to cull them, as this colour was considered a fault. In the 1960ies, however, a group of dog lovers formed an association for the White Shepherd and made it their mission to commit to buy all white-born German Shepherd puppies in the US and Canada, to prevent them from being killed. They then mated the white dogs that have come from different breeders and therefore had no genetic defects (other than the colour White), and out of these matings they got only white puppies, all healthy and without any genetic defects.
So, if there are two chameleon breeders who, by good luck, get babies with a new desired trait, they should breed those those unrelated animals and they will get only babies with the desired trait, but whith no genetic defects. That is responsible breeding and a thousand times better than inbreeding or line-breeding. The latter should only be used if, after diligent and thorough search, no unrelated mating partner with the same, accidentally occurred, desired trait can be found. Today, in the age of the Internet, it should really not be so hard to find a suitable partner somewhere in the world, and the air fare for such a rare animal will definitely pay for itself with rewarding the breeder with healhy happy babies rather than sicklish ones a majority of which he would have to cull.