Reptile & Amphibian Forums

I have read before and have read on many other forums about adding genetic diversity to captive breeding stock with new blood, or wild caught and collected snakes.

My question, is this really that big of a deal?

What has happend to the CB animals that have been bred without any new blood comming in?

What about an isolated area in the wild, where a certain species of snake has little genetics to choose from?

There would be crossbreeding going on in nature in these isolated areas would there not?

What about an island where one gravid female makes a swim and her and the babies beocme established would this also not include crossbreeding between siblings?

Not trying to stir the pot just want some opinions.

"I have read before and have read on many other forums about adding genetic diversity to captive breeding stock with new blood, or wild caught and collected snakes. My question, is this really that big of a deal?"

Yes, it is.

"What has happend to the CB animals that have been bred without any new blood comming in?"

It generally tends to result in a wide range of minor to severe defects. Below average growth rate and adult size in many "high end" Cornsnake morphs. Bug eyed leucistic Texas Ratsnakes. Albino boa's born with one or both eyes missing. Scaleless Texas Ratsnakes. The list goes on and on.

"What about an isolated area in the wild, where a certain species of snake has little genetics to choose from? There would be crossbreeding going on in nature in these isolated areas would there not? What about an island where one gravid female makes a swim and her and the babies beocme established would this also not include crossbreeding between siblings?"

Inbreeding definately also happens in the wild. Fortunately, there's also this thing called natural selection.
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I'm Dutch. Somebody shoot me.

"It generally tends to result in a wide range of minor to severe defects. Below average growth rate and adult size in many "high end" Cornsnake morphs. Bug eyed leucistic Texas Ratsnakes. Albino boa's born with one or both eyes missing. Scaleless Texas Ratsnakes. The list goes on and on."

If these anomalies are seen by the breeder, and then the said animals (and parents) are not allowed to breed or culled completley for humane reasons. Wouldnt this be the same as natural selection or are the variables of nature much more complex?

"If these anomalies are seen by the breeder, and then the said animals (and parents) are not allowed to breed or culled completley for humane reasons. Wouldnt this be the same as natural selection or are the variables of nature much more complex?"

No, and yes. When animals are bred to first degree relatives (f.i. brother to sister), each generation they loose 25% of their genetic variability on average. Visible anomalities are easy targets for selection, but it's the loss of genetic variability and thereby the accumulation of countless minor genetic defects which in the end will cause the demise of any linebred bloodline. Some will be sooner, some will be later, but the outcome is inevitable.
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I'm Dutch. Somebody shoot me.

. . .

Those defects you listed were all from morph inbreeding.

Many captive snakes have a large enough population not to need new WC blood. Just like stated with the island, a population can start up from very little original blood. Captive populations undergo new mutations just as they would in the wild and as they are bred new genes will randomly appear. These gene changes are not represented in wild snakes so the captive breeds will be slightly different. Additionally, rare genes could have been present in the WC snakes that started lineages. These genes will now represent a larger portion in captivity than in the wild. In captivity, brighter colors are usually selected for. We select for different genes than nature does.
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Nick Puder
www.rnpreptiles.com