Genetics

[poissonguppy]

So I was reading the really long discussion when Tina accidentally bred two garters.

I'm a little new so I'm not really understanding. Where's the dividing line between "okay" breedings and "not okay" breedings? Aren't a lot of hybrid garters the result of mixing together breeds? You don't find a lot of the morphs in the wild.

Thanks for the help.

[prattypus]

Not a breeder or a Jurassic Park genetist, and please correct me if I am wrong, but the morphs are various traits within a species or subspecies- like hair color, eye color, and all that jazz in humans.

So an albino plains bred with a normal plains isn't a hybrid. But a red sided that intergrades with a puget sound IS a hybrid.

[poissonguppy]

Ok, so I get that hybrids and morphs aren't synonymous. My bad...

But a red sided that intergrades with a puget sound IS a hybrid.

But would that be "okay" to do, or would that be messing too much with the gene pool?

[Stefan-A]

I'm a little new so I'm not really understanding. Where's the dividing line between "okay" breedings and "not okay" breedings?

That dividing line is between the ears of each person. There are people who'll breed anything with anything, there are people who won't breed snakes unless they belong to the same population and then there's every type in between. I, personally, am sort of a purist when it comes to these things and I prefer (although I don't require) that snakes come from the same population.

Aren't a lot of hybrid garters the result of mixing together breeds?

When it comes to garters, there are no breeds. The relevant terms are species, subspecies, localities and morphs (shout if you can think of another).

Mixing species results in a hybrid.

Mixing subspecies results in an intergrade, which is an intraspecific ("within the species") hybrid, although the term "intergrade" should in my opinion only be applied to a mix that has occurred in the wild (as opposed to captivity) in an area where this frequently happens. That means, in an area where two subspecies naturally meet. Not captivity, where they've been placed together. That's because "intergrade" has a slightly different connotation, because it describes a phenomenon that occurs where two closely related taxa meet. With captive animals , I'd personally prefer that people would call them hybrids, because that's what they are, regardless of whether or not they also occur under some circumstances in the wild. Not confusing enough?

Localities are what they sound like. Representatives from a certain geographical area, which could be as large as a country or as small as a village.

Morphs are different varieties within a taxon or a population. A "Nebraska albino Thamnophis radix" is an example of most of these things combined. Currently T. radix doesn't have any subspecies, but it is a distinct species, that shouldn't be mixed with T. sirtalis, for example. It is also a locality, in that it originates from Nebraska. The morph is "albino". In this particular case, the locality is of special importance, because the Nebraska albino is not "compatible" with the Iowa albino morph of the same species, because the mutation that causes albinism in them occur in different genes, so mixing them won't produce more albinos.

You don't find a lot of the morphs in the wild.

That's sort of true. Many morphs don't do well in the wild, but morphs can also simply be slightly lighter or darker than usual, or they can be melanistic. It's not always a detriment. But the important thing to understand, is that they all CAN occur in the wild, no matter how improbable it seems. That an anerythristic and an amelanistic garter would meet in the wild and produce offspring, is very unlikely, but there is no natural law that would actually prevent it.

Anyone, please correct me if I'm wrong.

[prattypus]

See, that's a heckuva lot more educated than my stab at it- Nicely stated Stefan

[poissonguppy]

I, personally, am sort of a purist when it comes to these things and I prefer (although I don't require) that snakes come from the same population.

What do you mean same population?

Haha, a little overload of info/vocabulary. But, I think I'm understanding a little bit of it. I'm not very strong in the basic genetics, so maybe I need a little more explanation... Sorry.

Like in dogs, a golden retriever and a rottweiler are the same species, but different breeds. So in the equivalent of garters, a T. radix and a T. sirtalis are the same species but different subspecies?

Do albino garters occur naturally in the wild? And how do you know which garters bred would produce albino's or not? (I'm just using albino as an example...)

In this particular case, the locality is of special importance, because the Nebraska albino is not "compatible" with the Iowa albino morph of the same species, because the mutation that causes albinism in them occur in different genes, so mixing them won't produce more albinos.

How do you know that they aren't compatible?

[Stefan-A]

What do you mean same population?

A biological population, i.e. a collection of organisms within a specific geographical area.

Haha, a little overload of info/vocabulary. But, I think I'm understanding a little bit of it. I'm not very strong in the basic genetics, so maybe I need a little more explanation... Sorry.

No need to apologize, we've all been there and we've never actually left.

Like in dogs, a golden retriever and a rottweiler are the same species, but different breeds. So in the equivalent of garters, a T. radix and a T. sirtalis are the same species but different subspecies?

"Morph" is the closest equivalent there is to a dog breed, but it's not quite the same. I'd have to do a taxonomy thread to explain it thoroughly (it has crossed my mind a few times), but Thamnophis is the genus and includes several species. Each species consists of smaller units, subspecies. The point of this system is to illustrate how animals are related to each other.

Do albino garters occur naturally in the wild?

Occasionally. What you do, is you catch them, breed them with a normal-coloured garter and then you breed the offspring (which in this case would be all normal-coloured) back to either the albino parent or each other to make that albino trait visible.

And how do you know which garters bred would produce albino's or not? (I'm just using albino as an example...) How do you know that they aren't compatible?

You breed two albino garters and they only produce normal-coloured offspring. If it was the same gene, some would be normal-coloured and some would be albinos.

[poissonguppy]

Thanks everyone! You cleared up a lot for me.

I think I understand a little more about species and the like.

Stefan, if you do end up writing a thread about it, I'd read it!

[prattypus]

I'll ask this now, since I've wondered about it, but never wanted to start a thread about it. How big of a concern is inbreeding? If you breed the offspring back to their parents, or other siblings- how high is the risk of birth defects, and the like?

[Stefan-A]

I'd better let the actual breeders answer that question.

It varies, though. You can do it for a few generations without any issues, but eventually, it's going to start reducing the viability of the offspring and cause abnormally high rates of defects and stillborn, reduced life expectancy, weaker immune systems, smaller and weaker offspring and various hereditary problems. Dog breeds have their typical health problems and so will different morphs have, eventually. But this is just a general answer.