Reptile & Amphibian Forums

Ok, so from what I understand, scientists now feel that inbreeding of relatives is not as harmful as we once thought.
A first or second generation pairing has very little (if any) increased chance of mutations.

It's when you continue to inbreed generation after generation that things become problematic and the chances of mishap go up faster.

Anyone have any thoughts on this?

The more you inbreed the greater the chance that the offspring will end up with double copies of deleterious recessive genes. Most individuals do have single copies of many harmful genes (there are so many out there in this world) but when you breed with an unrelated individual the odds that that individual has a copy of the same gene is quite small. If you breed with someone who is 50% related to you (sibling, parent) then those odds go up significantly. When working with hybrid strains inbreeding is a pretty common practice not only in snakes but things like dog breeds as well. I've heard from some people that if any of the offspring ever show signs of reduced fitness due to inbreeding (kinked back or something) they just feed them to their kingsnakes or something. I guess that system works...

n/p
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"Better to be silent and thought a fool, than to open mouth and remove any doubt!"

Some (including me) have a moral issue with inbreeding.

I won't even do it with my feeder mice.

Genetics aside, would you plan a family with your bro/sis ?

Regards,
Wayne A. Harvey
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1.2.9 Storeria dekayi Casper, Xena, Athena, & Kids
0.0.2 Thamnophis marcianus - Checkered Garter Snakes
0.0.1 Thamnophis sirtalis - common Garter - Princess
0.0.1 Nerodia sipedon - Water Snake - "Aqua"
0.1.10 Storeria occipitomaculata - Red Belly snakes
0.0.1 Amelanistic Corn Snake "CY" Juvinile CB
0.1.0. Pueblan Milk snake "Oreo" adult CB
1.0.0. ASIAN GREEN SNAKE 3' WC Cyclophiops major
0.0.1. Savannah Monitor "CHOMPER" CB
0.1.0. Green Anole "Crystal" WC
1.0.0. K9 "ACE" Black Cockapoo
1.2.0. Feline"Felix" "Kaja" & "Silver"
0.1.0. calico RAT
2.4.?? Mice - Feeder farm - Crickets / fish
More herps than I could ever list out back on the land.

Well interestingly enough, I feel the same way.

But one wonders where most of our morphs come from. Its very likely the majority actually came from inbreeding.

You are right on target, many snake breeders will inbreed to obtain a desired color pattern.

Research (from what I have read) indicates that life spans may be reduced from the weakened genes.

To me, since the breeders generally do so for profit, they should invest in "un related bloodlines" As the breeders that I have respect for do.

Regards,
Wayne A. Harvey

our critters

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1.2.9 Storeria dekayi Casper, Xena, Athena, & Kids
0.0.2 Thamnophis marcianus - Checkered Garters "spot" & "Zig"
0.0.1 Thamnophis sirtalis - eastern Garter - Princess
1.0.0 Thamnophis pickeringi - Puget Sound Garter "Sky" (adult, Sky blue)
0.0.1 Nerodia sipedon - Water Snake - "Aqua"
0.1.10 Storeria occipitomaculata - Red Belly snakes
0.0.1 Amelanistic Corn Snake "CY" Juvinile CB
0.1.0. Pueblan Milk snake "Oreo" adult CB
1.0.0. ASIAN GREEN SNAKE 3' WC Cyclophiops major
0.0.1. Savannah Monitor "CHOMPER"
0.1.0. Green Anole "Crystal" WC
1.0.0. K9 "ACE" Black Cockapoo
0.2.0. Feline"Felix"(R.I.P. 4/27/08) "Kaja" & "Silver"
0.1.0. calico RAT
2.4.?? Mice - Feeder farm - Crickets / fish
More herps than I could ever list out back on the land.

not that this gets around the inbreeding aspect but keep in mind that when creating hybrids someone will naturally be required to start with two completely unrelated adults (not even the same species). This at least means that the initial cross is very unlikely to end up with a homozygous set of a deleterious gene. The problem here actually can be with the outbreeding -- each species generally has a huge set of co-adapted gene complexes where a certain combination of like 50 or 100 or 1000 (w/e) genes interact with one another to create a very fit snake. When you outbreed with another species (or even a different local strain) you can muck up those co-adapted gene complexes and create individuals that have reduced fitness. This tends to be OK in captivity but it is the largest reason why you rarely see hybrids in the wild. You often end up with individuals that produce sexual pheromones that neither parent species is attracted to or it will try to breed the wrong time of year or it will select nest sites that are a cross between two suitable types but are actually unacceptable and result in egg mortality.

It has recently been shown that in the wild many salamanders will preferentially breed with individuals that are more closely-related. Polypaternity is very common and I think about 60% or so of the eggs end up being from cousins even though cousins make up far less than 60% of the population. The idea is to try and preserve those co-adapted gene complexes but maintain genetic diversity by also breeding with some newbs from another population. In the case of salamanders though they lay hundreds of eggs at once so they have the option of playing around a little more than snakes. It's just something I thought may be relevant.

I do not consider inbreeding to be completely immoral (in animals) but making a habit of it can result in bad things. To give some numbers starting with unrelated adults:
Father has 1 copy of a recessive gene for a kinked spine.
Offspring then has 50% chance of having that gene.
When you cross two siblings the chance that they BOTH have that gene is 25%.
If both the siblings DO have the gene then the odds of their kids having two copies of the gene is 25%.
If the only assumption you are making is that 1 parent had 1 copy of the kinked tail gene then the odds that the grandkids would have two copies is 25% of 25% OR 6.25%.
If you consider that you'll probably do this multiple times and end up with dozens of offspring in this generation then the odds of having some "rejects" with kinked spines is quite high. Now consider that BOTH parents probably have single copies of multiple deleterious recessive genes then the odds that something will go wrong is VERY high in at least some of the offspring. This is a very simple system that works only with single-gene traits. Like co-adapted gene complexes there are many genetic diseases that require interactions on many genes so the odds that those problems will arise are much smaller. If you continue to cross the siblings from each batch the next generation gets more and more related and the chances of bad gene complexes coming out increase with each and every generation.

Some pretty cool morphs have come out of this but if you have the time and space it would be best to get several lines going at once and cross unrelated hybrid offspring to reduce the inbreeding coefficient.

Long story short, inbreeding does occur in the wild (probably even in snakes) so that co-adapted gene complexes that work best in a specific habitat are maintained but there must be some outbreeding to maintain genetic diversity and reduce the risk of genetic disease. Outbreeding with another species is avoided almost entirely. When making crosses in captivity you don't have to worry so much about preserving those co-adapted gene complexes but problems can and will arrive as a result of inbreeding. Inbreeding a little you probably won't see many bad results but the more and more you do it the odds that you'll get "rejects" increase and the number of duds per clutch increases as well. A lot of the time you get embryos that simply aren't viable and never even leave the mother snake...

I hope that made some sense... For the record, I've never done this. This is actually the first time I've put any real thought into the numbers behind hybrids and inbreeding to create morphs. I just sort of typed my thoughts as I was having them so a few things might have come out confusing

hybrids aside, you often NEED to inbreed when trying to find morphs like albinos and stuff. those "cool" traits work the same as genetic diseases. The more you inbreed, the more likely the genes will be expressed. I think a lot of the time when a morph is created from inbreeding the breeders try to outbreed the next generation to get rid of all those bad traits that may have been passed on as well.

It guess this makes rednecks more socially acceptable! OK, so its not that funny.

Dave

Humor, Ha Ha

Slight chuckle

Regards,
Earl and uncle daddy Carl

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1.2.9 Storeria dekayi Casper, Xena, Athena, & Kids
0.0.2 Thamnophis marcianus - Checkered Garter Snakes
0.0.1 Thamnophis sirtalis - common Garter - Princess
0.0.1 Nerodia sipedon - Water Snake - "Aqua"
0.1.10 Storeria occipitomaculata - Red Belly snakes
0.0.1 Amelanistic Corn Snake "CY" Juvinile CB
0.1.0. Pueblan Milk snake "Oreo" adult CB
1.0.0. ASIAN GREEN SNAKE 3' WC Cyclophiops major
0.0.1. Savannah Monitor "CHOMPER" CB
0.1.0. Green Anole "Crystal" WC
1.0.0. K9 "ACE" Black Cockapoo
1.2.0. Feline"Felix" "Kaja" & "Silver"
0.1.0. calico RAT
2.4.?? Mice - Feeder farm - Crickets / fish
More herps than I could ever list out back on the land.

If I can stray from the subject just a bit (I guess I already did!) that background is just all kinds of cool.
Dave

Hey! This ol' redneck hillbilly happens to think it's kinda neat that me momma is me sis.

Yer jus' jealous that yer sis don't look like Angelina Jolie, minus a few teeth and a good hair brushin'.

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Due to political correctness run amuck,
this ol' hillbilly is now referred to as an:
Appalachian American

www.natures-signature.com

Yehaw bubba

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1.0.0 Ball Python - Python regius "Cane" Rescue
1.2.9 Storeria dekayi Casper, Xena, Athena, & Kids
0.0.2 Thamnophis marcianus - Checkered Garters "spot" & "Zig"
0.0.1 Thamnophis sirtalis - eastern Garter - Princess
1.0.0 Thamnophis pickeringi - Puget Sound Garter "Sky" (adult, Sky blue)
0.0.1 Nerodia sipedon - Water Snake - "Aqua"
0.1.10 Storeria occipitomaculata - Red Belly snakes
0.0.1 Amelanistic Corn Snake "CY" Juvinile CB
0.1.0. Pueblan Milk snake "Oreo" adult CB
1.0.0. ASIAN GREEN SNAKE 3' WC Cyclophiops major
0.0.1. Savannah Monitor "CHOMPER"
0.1.0. Green Anole "Crystal" WC
1.0.0. K9 "ACE" Black Cockapoo
0.2.0. Feline"Felix"(R.I.P. 4/27/08) "Kaja" & "Silver"
0.1.0. calico RAT
2.4.?? Mice - Feeder farm - Crickets / fish
More herps than I could ever list out back on the land.

Awesome houseboat dude!,.......is that you "captaining" the helm of the good ship "Lolly Pop"?

Too funny!

~Doug
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"Better to be silent and thought a fool, than to open mouth and remove any doubt!"

I don't know how to break this to ya, but, that ain't no redneck or hillbilly's houseboat, I gar-run-tee ya. If it were, it would have an ol' U-Haul truck box on it instead of a gen-u-wine camper.

I would show ya a pic of mine but it's sittin' at the bottom of the lake. them thar styrofoam ice chests won't hold up an old U-Haul box very well.

I wondered if ya'll were wonderin' if my first reply was serious or not. Haha!

Later!
HH
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Due to political correctness run amuck,
this ol' hillbilly is now referred to as an:
Appalachian American

www.natures-signature.com

Stepping on your snake just a little bit. Just once in awhile, might not hurt it. But you shouldn't step on your snake.