Breeding, genetics and colors.

[Raya]

Hi!

I've got some questions that maby someone who has breeding experience or has knowledge about genetics can answer.

When I was keeping mice as pets I used to hang at forums who had alot of breeders. They discussed fur-types, colors and the genes behind them. Many had like one type that they bred and was trying to perfect.

Can 't say I understod much of the genetics but I was wondering if this is possible when breeding frogs and toads? I mean, with species that varies alot in color like Bufo melanostictus. Could you breed these and only continue breeding the ones with the brightest coloring? Will that result in "better" colored offspring?


Now when I think about it. Isn't this what the pacman-breeders are doing? Maby someone with more insight can say a few words on how this works?


Thanks!
/ Raya

[SkeletalFrog]

Yep, you can selectively breed anything - frogs, fruit-flies, mice, elephants. You just need a suitably large number and a stable breeding criterion (better color, size, etc.).

The key is population size - too few animals and you wind up with inbreeding, which has long-term damaging effects on animal health (smaller size, reduced lifespan, reduced number of offspring, physical abnormalities, etc.). Consider lab mice, which are highly inbred and live for only 3 years versus their wild cousins who live for 7. To really safeguard, you need huge populations (over 500), but you can cheat by hand-picking wild-caught individuals of exceptional pattern and adding them to your breeding program every generation (maybe tell the local importer you'll pay triple for any truly awesome individuals).

However, this is very different from breeding albinos and similar "one-gene" traits, where everything is governed by a single gene. In those cases, it is impossible to perpetuate the line without some degree of inbreeding. How much inbreeding and the final long-term consequences vary with population size and how much new genetic material you introduce - if you just rampantly breed siblings, the line will collapse, but if you take pains to introduce new blood and avoid sibling or first-cousin matings, the effects will show up more slowly and likely be less severe in the final line. But large populations and new blood cost money and time. You see the problems with this in albino boas which, thanks to many generations of severe inbreeding, are now producing offspring with one or no eyes.


Short version - selective breeding can work, but you need large populations to avoid disaster. If it's just color, not something like albinism, you can easily supplement with wild-caught individuals.

[Raya]

Thanks alot for the answer!

It was kinda what I thought. That it's possible, but as you say, would require more animals than if you "just breed" to get offspring.
It would be harder here in Sweden since we're not allowed to have wild caught animals at all. So we only have the animals already in the hobby and can not get fresh blood in as easy.