Inbreeding, linebreeding reptiles Debate V1.0

[natas]

This is version 1 of the debate "Inbreeding, linebreeding of reptiles.". What this thread is not is a place to come and insult, mock, degrade or put down members for their views. Engage the debate in the spirit in which it is meant to be debated.

In this thread we will talk about the following:

* Is there a proper way to linebreed or inbreed a reptile?
* Should linebreeding or inbreeding ever be allowed? If so when?
* Will linebreeding be the demise of the reptile trade?
* Other arguments on linebreeding and inbreeding reptiles.

Special rules for this thread:
1) As always, please stay on topic. Off topic replies, will be removed.
2) Limit small replies like "that was awesome", or "Your wrong". Instead of replying like this, use rep or the "thank you" button.
3) Try your best to back your statement up with scientific fact, studies you have read or done.
4) DO NOT plagiarize. If you quote someones findings, please give credit by providing the name, or a direct link.
5) Before posting, please read the rules of this forum.
6) 10 day bans for personal attacks on persons or companies.

THIS IS NOT A ALBINO IS WRONG OR RIGHT THREAD. Go debate here for that.
THIS IS NOT A MORPH BREEDING IS WRONG OR RIGHT THREAD. Go debate that here.

Enjoy, and have fun!

[deadliestformula]

Inbreeding Depression as defined by Wikipedia --"Inbreeding depression is reduced fitness in a given population as a result of breeding of related individuals. Breeding between closely related individuals results in more recessive deleterious traits manifesting themselves. The more closely related the breeding pair is, the more homozygous deleterious genes the offspring may have, resulting in very unfit individuals. In general, populations with more genetic variation do not suffer from inbreeding depression. Inbreeding depression is often the result of a population bottleneck. The phenomenon of inbreeding depression may occur in either plant or animal species."



A specific citation of inbreeding depression in Vipera Berus--

"In a small population, matings between relatives are common. This inbreeding may lower the population’s ability to survive and reproduce, a phenomenon called inbreeding depression. For example, a population of 40 adders (Vipera berus) experienced inbreeding depression when farming activities in Sweden isolated them from other adder populations.1 Higher proportions of stillborn and deformed offspring were born in the isolated population than in the larger populations. When researchers introduced adders from other populations—an example of outbreeding—the isolated population recovered and produced a higher proportion of viable offspring.


The explanation for inbreeding depression lies in the evolutionary history of the population. Over time, natural selection weeds deleterious alleles out of a population—when the dominant deleterious alleles are expressed, they lower the carrier’s fitness, and fewer copies wind up in the next generation. But recessive deleterious alleles are “hidden” from natural selection by their dominant non-deleterious counterparts. An individual carrying a single recessive deleterious allele will be healthy and can easily pass the deleterious allele into the next generation.

When the population is large, this is generally not a problem—the population may carry many recessive deleterious alleles, but they are rarely expressed. However, when the population becomes small, close relatives end up mating with one another, and those relatives likely carry the same recessive deleterious alleles. When the relatives mate, the offspring may inherit two copies of the same recessive deleterious allele and suffer the consequences of expressing the deleterious allele, as shown in the example below. In the case of the Swedish adders, that meant stillborn offspring and deformities.



For Swedish adders, the solution to the inbreeding depression problem was simple—introduce adders from other populations. But if the northern hairy-nosed wombat suffers from inbreeding depression, there are no other populations that can rescue it. Understanding the evolutionary history of a population and the likelihood that it carries recessive deleterious alleles, suggests that we should not allow population sizes to dip too low in our conservation efforts, or inbreeding depression may jeopardize the survival of the species.

1 Madsen, Thomas; Stille, Bo; Shine, Richard. Inbreeding depression in an isolated population of adders Vipera berus. In: Biological Conservation 1996. 75 (2): 113-118. "

This was quoted from : Relevance of Evolution: Inbreeding Depression p. 1



As the article above stated, outbreeding is important to the prevention of inbreeding depression. In fact outbreeding is essential in diversifying the gene pool.

When breeding for morphs, some degree of inbreeding is necessary as stated here -- "A more common reason for inbreeding is the reproduction of various mutations, such as albinism. Such mutations can represent a large financial investment, as well as being of general interest to many, and there is much incentive to reproduce such individuals. There is absolutely no way to produce additional specimens of these rarities without inbreeding them to some degree. That's simply the reality of it. Each and every albino Burmese Python is in some way related to every other albino Burmese Python. That's just fact."

quoted from The Learning Center - Inbreeding Discussion


As proven in the study of the adders mentioned above, outbreeding is necessary to prevent the 'weakening' caused by inbreeding depression. Responsible development of morphs SHOULD include introduction of unrelated snakes into the gene pool. An example of this would be this: assume the snake carrying the desired morph gene is a male, Breed him to 2 unrelated females of wildtype. This would create 2 clutches of 'hets'. These hets are then not related thru both mother and father, and are only related thru the father. Frequent outbreeding of the morphed animal(s) to wildtype normal animals would increase the available genetics and give you many different 'hets' to breed from.

"A method of primary importance is to utilize out-crossing wherever practicable. Out-crossing involves taking your cherished albino specimen and breeding it to two unrelated wild specimens. You'll now have two groups of heterozygous for albino specimens which are only half-related to breed together. This is much better than breeding the albino directly to his sister, as many new alleles will have been introduced into the population using this method.

Where possible, breeders should attempt to acquire specimens which are unrelated, or close to it, for use as breeders. The use of large groups of unrelated breeders will allow production of many unrelated or partially related offspring by making different pairings each year. "

quoted from The Learning Center - Inbreeding Discussion


Proper record keeping is something that should be stressed among breeders and hobbyists alike (similiar to the way the dogs lineage are kept by the AKC). Then a breeder would have the records necessary to determine the 'relatedness' of animals and select the least related ones possible for the project. This is an undertaking that is almost impossible without universal support. But a universal registry has been started with cornsnakes located here American Cornsnake Registry - Home . This registry is a giant step in the right direction, but it will take lobbying to the breeders from concerned individuals to make this a mandatory requirement.

[deadliestformula]

There is a mathmatical equation for figuring out the level of relatedness between 2 individuals. This result is called the CoEfficient of Inbreeding.

The coefficient of inbreeding is defined as :
1. the probability that the progeny of a union will be homozygous for a specific autosomal allele derived from a common ancestor.

found at Medical Dictionary, Hospitals, Pharmaceutical Company and Medical Associations Searches

If breeders kept records of the breedings of animals, the coeffiecient of inbreeding could be used to determine the level that animals are related. Then breeding projects could be chosen, (and outbreeding used) to lower the COI to a minimal level, which would then decrease the probability of inbreeding depression related problems, while still propagating the gene they are breeding for. There are many places online that explain how to compute the COI manually, however the equations become very complex when animals share more than 1 common ancestor. There is a free online program that I found called FSpeed (located here: FSpeed - Fast Calculation of Inbreeding Coefficient ) that will compute the COI for you. Other breeding programs that compute this as well as keep records are easily a click away.

[JuliusSqueezer]

If every morph of any given type in the pet trade is related then that's due to man's poor ethics, lack of patience and greed. If it happend once, chances are it happened before and will again. There is no excuse for inbreeding. These defects that people think are a cool trait (and some actually are pretty cool) first occur because when the DNA Helix splits and copies it's self to pass on traits to offspring, now and again they don't copy exact and mutations occur...sort of a genetic typo. Unfortunatly when this happens it very often also miscopies other things and causes other genetic traits to tag along with the "cool" trait that may not be so cool. If you breed 2 naturally occuring but unrelated similar morphed animals with the same cool genetic code, then the chances any of the same unfavorable/health related consequences would be much lower. By inbreeding them, you INSURE that any defects are also passed to all offspring. But sometimes we can't find another one...well woopidy do. Pain and suffering of countless animals isn't worth propegating any cool morph. The world will be no better off because you put out some pink and purple polkadotted boa constrictors. It will however be worse off if you cause the future suffering of thousands of heartbreaking mutants that weren't meant to be and won't live full healthy lives often if at all.

a few examples of captive inbreeding depression that we never would have even heard of if the original breeders practiced a little ethics. These examples are all widespread and very common. There are of course other inbreeding related malformities that never get propegated due to either early deaths, small isolated breeding projects that don't ever become mainstream, or breeders at least having enough morals to quit when they see it and cull rather than sugar coat it with deception.

Green burmese pythons. (BD)
One eyed albino boas
Bug eyed -mentally challanged leucistic texas rat snakes
Bobble head neurologically diseased spinning spider ball pythons
Same as above for bumblebee ball pythons
Kinked carmel ball pythons
Fuse toed leopard geckos

I can't speak for everyone I guess but I would waaaaay rather have never seen a spider ball python than to see all these poor wobbly sickly bobbleheads. Albinism is a diease in and of it's self but that's for another debate I guess so I find it a compounded ethical travesty to inbreed for that trait. I've heard many breeders admit that they will breed known problematic morphs that suffer from inbreeding depression because there's a good chance that SOME of the babies will come out unsymptomatic. Wow...all the others that suffer and die are worth it so a few MIGHT make it?

Another issue I have with inbreeding is even in the cases where it doesn't show outward signs of problems, the word YET becomes ever important. Once it starts, where does it end? The high prices of these animals commonly inbred are sold to other people that want to cash in too. The easiest way is to inbreed an already inbred who knows how many generations line...but they were told that a couple of generations don't matter and few people seem to realize that if you inbreed an already inbred line, you ARE NOT starting at ONE! Family trees don't reset at zero because of change of ownership.

[deadliestformula]

The problems that I see involved with the 'wait until it happens again' idea are these:

1. What if it happens again in an animal of the same sex?

2. What if the original animal is dead by the time 'it happens again'?
(this could be a real possibility as most of the unusual 'new' genetic morphs come as wild caught harvested animals and we know the problems that may arise from wild caught specimens including but not limited to over stressed, refusal to eat in captivity, etc)

"It is estimated that wild-caught reptiles experience, on average, a 90% mortality rate between capture and the end of their 1st year of captivity. Fritz Jurgen Obst, the author of Turtles, Tortoises and Terrapins has estimated that 99% of all hatchling turtles …die in the first year. One estimate states that 90% of snakes die within the first 6 months of ownership.

The vast majority of overseas reptile collectors and exporters spend a minimum amount of time caring for their catch. Rarely is food or water given because collectors and dealers know that many reptiles can live for a long time without these basic items…[and] health problems appear weeks or months later, often after the animal is purchased by the end consumer. Turtle veterinarian Barbara Bonner…has stated that virtually all pet turtles are desperately sick when purchased from pet stores.

Wild-caught animals do not adapt successfully to captivity…and most die within a short time after purchase by the average consumer."
Reptiles as Pets, An Examation of the Trade in Live Reptiles in the United States: Joseph Franke, MS & Teresa Telecky, PhD, Humane Society of the United States

3. If it does 'happen again' who's to say the animal will even make it to the market (particularly in the case of harvesting, the creature may never be found)

4. If it actually makes it to the market, what if the person holding the 1st one is either unable to acquire the 2nd one, or a rival breeder acquires it? Neither breeder would be willing to miss out on the 'new cool morph that could be sold for $$$$$$, and that competetiveness would lead to failure to cooperatively breed, or even a crime to acquire it. Case in point--the break in at Bob Clarks that resulted in the theft of his foundling male albino BP as well as his entire stock of albino hets Bob Clark Captive Bred Reptiles - Albino Ball Python.

5. As with albinism, many other characteristics that make morphs more unique and desirable, are actually a hinderance in their native environment. Such as increasing their visability to predators. So there is the chance that animals with the visable trait will not be available to harvest because they have a harder time with survival in general.

"Traits which are favored by the environment(adaptive) will result in a greater number of organisms produced than those with traits which are not favored by the environment(maladaptive).

**A simple example of this difference in reproductive fitness can be observed in virtually any albino animal. Albino animals are at a disadvantage, as such a trait is not favored by the environment(it is very difficult to hide/disguise oneself from predators as an albino). Albino individuals are typically discovered and killed long before they ever get a chance to reproduce, and pass on their genetic material(albinism) to their offspring. Therefore, albinism does not become established within a population or a species, because natural selection does not favor the trait's success. In the case of snakes or lizards, cryptic coloration is adaptive, as it decreases the chances of predation, and increases the chances of surviving to reproducel. This is why there are no wild populations comprised of albino individuals.

It is important to understand that natural selection works on individuals, not populations or species. Since individuals which are better suited to their environment are the ones who typically survive to reproduce, a population or species thus becomes better suited to its environment, as more individuals possessing the favorable traits are produced, and fewer individuals with non-favorable traits are produced. "
Untitled Document


As it is a business, waiting for 'it to happen again' is not always economically feesable, or even possible. And inbreeding has occured in MANY animals, not just reptiles. Your purebred dog or cat was probably inbred at one point or another when establishing the unique characteristics of its breed.

"Inbreeding is the mating together of closely related cats, for example mother/son, father/daughter, sibling/sibling matings and half-sibling/half-sibling. It is the pairing of animals which are more closely related than the average population. For breeders, it is a useful way of fixing traits in a breed - the pedigrees of some exhibition cats show that many of their forebears are closely related. For example, the name of Fan Tee Cee (shown in the 1960s and 1970s) appeared in more and more Siamese pedigrees, sometimes several times in a single pedigree, as breeders were anxious to make their lines more typey. Superb specimens are always much sought after for stud services or offspring (unless they have already been neutered; cloning may solve that problem in the future) having won the approval of show judges.

To produce cats which closely meet the breed standard, breeders commonly mate together animals which are related and which share desirable characteristics. Over time, sometimes only one or two generations, those characteristics will become homozygous (genetically uniform) and all offspring of the inbred animal will inherit the genes for those characteristics (breed true). Breeders can predict how the offspring will look. "Line-breeding" is not a term used by geneticists, but comes from livestock husbandry. It indicates milder forms of inbreeding. Line-breeding is still a form of inbreeding i.e. breeding within a family line and includes cousin/cousin, aunt/nephew, niece/uncle and grandparent/grandchild. The difference between line-breeding and inbreeding may be defined differently for different species of animals and even for different breeds within the same species. It is complicated by the fact that a cat's half-brother might also be her father!"
Pros and Cons of Inbreeding

"But, all pure breeds of domestic animals are inbred. (Keep in mind that to a scientist “inbreeding” means the breeding of related animals, which would include what we call “linebreeding.”) But how much is too much? Without it, the breeds could never have been developed and would not breed true to type.

However, almost all breeds of purebred dog already have well-established type. There is no mistaking a Chihuahua for a St. Bernard. Or even a Greyhound from a Whippet. Given this, breeders would be well advised to retain as much genetic diversity as possible within the existing breed population in order to avoid or reduce such unwanted health problems as those mentioned above. Along with screening and maintaining detailed health records, another tool available to you is the Coefficient of Inbreeding. Track COIs on your breeding stock. Calculate them on proposed matings, with an eye to keeping the numbers low if they already are or lowering them where possible. "
Australian Shepherd Health & Genetics Institute, Inc.

"It is by no means uncommon in dogs, for instance, to have pedigrees which can be researched in the AKC stud book and the KC Gazette and which go back to foundation dogs born around the turn of the century - perhaps 30 or even 40 generations earlier. With this type of long pedigree, foundation animals may appear a million times or more in the pedigree."
Inbreeding and Linebreeding



Because it WILL happen to prove out a morph, or to repopulate a dwindling species, we must understand how it effects our animals, and using methods above (such as the COI, and outbreeding) we can do it in the SAFEST method possible, and attempt to keep as much diversity in the gene pool as we can. RESPONSIBLE BREEDING is the key here.

"For practical purposes, if two mated individuals have no common ancestor within the last five or six generations, their progeny would be considered outbreds. " G2911 Inbreeding: Its Meaning, Uses and Effects on Farm Animals, MU Extension

This is the KEY. Of course most animals share one common ancestor and are therefore inbred to begin with. The real point is when does it become a problem, and if care is taken with each breeding to prevent more inbreeding than is necessary, it can be done responsibly.

After all it wasn't so long ago that an article was published saying that humans could all be traced back to one of 7 mothers. BBC News | SCI/TECH | Europe's seven female founders

So technically we are all related to one another and inbreeding each and every time we have a child. It is a matter of degrees of inbreeding as I have said before.

[SoberGuy]

I'll post this on the other pertinent thread too, but directly from Mr. Clark himself:

"The snake fed voluntarily in due time, and while it was thought to be too small to breed, it did so that fall. The heterozygous generation hatched in the spring of 1990. These snakes grew quickly, bred and laid eggs that hatched when they themselves were only 2 years old."

Breeding when not old enough and not quite big enough? That's one more reason why it ain't good.

[deadliestformula]

Originally Posted by SoberGuy

I'll post this on the other pertinent thread too, but directly from Mr. Clark himself:

"The snake fed voluntarily in due time, and while it was thought to be too small to breed, it did so that fall. The heterozygous generation hatched in the spring of 1990. These snakes grew quickly, bred and laid eggs that hatched when they themselves were only 2 years old."

Breeding when not old enough and not quite big enough? That's one more reason why it ain't good.

That is an example of poor breeding practices. But although breeding too early is a problem in and of itself, it is not the same as inbreeding. The 2 may go hand in hand, especially when the almighty dollar comes into play, but it isn't the same. And it all boils down to what I said earlier, RESPONSIBLE BREEDING practices are needed. Efforts need to be made to ensure that animals are mature enough for breeding, and that outbreeding is used to strengthen and diversify the bloodlines.