Thank you for breaking this down and clarifying, I kept hearing things about inbreeding from Youtube breeders that were the opposite of what I learned in school and was getting confused.
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That was an intensely intelligent way to express this topic with very valid reasoning.
I enjoyed reading that very much, and it does have me thinking about the wild arguments towards inbreeding.
I do have one question tho regarding this statement, which is not connected to the inbreeding topic at hand.
Due to Ball Pythons low fecundity, wouldn’t that suggest their offspring of any given clutch has a higher rate of survival? Low fecundity is a sign that particular species does not need to reproduce in large numbers because more survive to adulthood.
So instead of 1-2 animals making it to sexual maturity, wouldn’t the estimated number be closer to 4-5, say out of a clutch of 10?
Or am I way off?
Two answers for you here: No, but also, yes (clear as mud right? LOL)
So, the lower fecundity we see in balls is more in captive balls versus wild balls. Wild ball pythons, by and large, tend to produce larger clutches than what we typically see in captivity. This is one of the unintended consequences of the hobby where in we have inadvertently been selecting for females that breed sooner. Inevitably those females are smaller and, as such, cannot produce large clutches (a 2500g female has more room in her body to nurture 10 eggs better than a 1200g female)
That said, yes, the odds of one of their offspring making it to maturity are higher, but that is why their clutches are smaller than some comparable species of the same size/stature. I am grossly over-simplifying this statement but, evolution has kind of landed at the breeding strategy wherein a species, in a sort of checks/balances way, invests the minimum amount of energy/time/effort/production necessary so as to produce the minimum number of offspring necessary in order to ensure one copy of their genome survives.
- A female that uses all of her energy reserves to produce a 25 egg clutch ends up not having sufficient energy left to coil her eggs and dies while nesting them. Her dead body begins to rot and attracts scavengers that eat her remains and also the clutch. Her genes are now erased from the population.
- A female that uses hardly any of her energy reserves to produce a 3 egg clutch ends up successfully incubating her clutch, but natural attrition results in none of the offspring surviving to maturity. Her genes are now erased from the population.
- A female devotes enough of her energy reserves to produce a 7 egg clutch and make it through the incubation somewhat weakened but generally healthy. Natural attrition results in 1-2 of the offspring surviving to maturity. Her genes are sustained in the population and continue to be passed along.
Make sense?
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That actually makes perfect sense. I wasn’t aware that wild females would produce larger clutches, I thought it would be the opposite due to the amount of food readily available in captivity.
Thank you Dr. Wyman.
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But this is something else that comes with huge changes depending on certain factors.
In captivity, we feed ~ once a week (Ive recently changed from every 10 → 14 days).
This is my uneducated thoughts-
In the wild they search for burrows, block the way out and eat as many as they can before they escape. They are likely getting 3/4 times as much per meal. Now it might be less frequent but that only helps to increase the amount of weight their body will hold on to.
Their internals know that they might go without food for a little while and stores everything it can (where as our snakes might be able to assume they will be fed regularly and not have the need to store as much). Add in the fact that they are not climbing trees all day and spend most of the time either still or slowly moving, they aren’t burning much off.
Also the rodents in the wild are eating anything and everything, grass, seeds, MEAT, hair, bones… hell, even each other if needs be. The snakes are getting much richer and varied diets through wild rodents.
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But how do we take advantage of the amount of food available in captivity?
By pushing as hard as we can to get the females to reach that imposed minimum weight to breed so that we can breed them as soon as they hit it. And then, because as soon as they hit that size we breed them and, in doing so, cause a massive energy deprivation to their system that stunts their growth/productivity.
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Very true. I don’t breed any of my balls until they hit at least 3yrs old, not dependent on weight or even if they can breed earlier. I’ve even waited till 4 years because I just don’t see the benefits of breeding them early.
But I did forget to take into account that most breeders want to breed as early as possible, and there are definitely side affects to that.
Again that makes a lot of sense to the difference in adult females in the wild and adult females in captivity, despite if they get food more regularly or not.
Thanks for always taking the time to make sense of these situations.
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Focusing back to the original question, the underlying reason inbreeding is considered an issue from a genetic standpoint is exactly that, genetics.
Mutation occurs naturally within a population at an individual level, however, this mutation is not always phenotypical. Mutations can range from changing the color of a species, a phenotypical change, to a predisposition for cancer, a genotypical change. These mutations are at the cellular level and aren’t easily noticed unless using scientific tests, such as SNP mapping, to determine the exact order of certain nucleotides. This is also difficult, however, as only a few key species have had their entire DNA mapped to this extent. (These species being those that science has deemed ‘beneficial’ for research such as fruit flies and white mice). We actually can test human beings for their proclivity towards certain degenerative diseases, such as Alzheimer’s, this way.
If a specific individual were to have gotten such a mutation at birth (assuming it’s recessive), two outcomes are possible. One, this mutation is strictly within this one individual and it will more than likely not stick around too long regardless of who it breeds to. Or two, this mutation was actually passed on to all the offspring in this clutch. If the latter is assumed, breeding two offspring from this clutch together will guarantee each child they produce is homozygous for this rare disease, which wouldn’t have happened if not bred together.
This is a gross oversimplification of everything, but the bottom line is when inbreeding you have a higher chance of seeing rare genetic diseases and predispositions towards such diseases. Does this mean inbreeding is bad? No, it can, as stated, be beneficial at times. Does this mean you’re always going to get a genetically weak snake from inbreeding? No. It simply means that you’re risk factor is greater, it may only be minimally greater, but it’s greater nevertheless.
Wow, this is very interesting! I always thought that inbreeding is 100% a really irresponsible thing to do. I’m involved in the zoo/aquarium world and in our species conservation programs, we keep meticulous records of lineage in order to avoid ever inbreeding. Breeding pairs are carefully matched, and often an animal will be shipped around the world to a new zoo in order to increase genetic diversity. Certain species of fish common in the home aquarium trade (e.g. guppies) have gone from very hardy to often sick and unreliable because of inbreeding, either to highlight certain colors or just because breeders didn’t bother to separate parents and their offspring. Many breeds of dogs have similar issues because breeders have long prioritized the classic look over health. But I suppose that in a species with a large enough number of animals in captivity, specific instances of inbreeding are unlikely to have a large-scale effect.
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I can definitely see why inbreeding in zoo stock and conservation programs would be a very bad thing. If you inbreed, say, giraffes and one of the inbred groups get sick, then the rest would likely follow. Then if the first one dies the rest could follow. You also risk behavioral issues with wild animals that make them much more dangerous and unpredictable. Take white tigers for example, they tend to be more sickly and aggressive from what I have heard.
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so, um, i dont know much about snakes and inbreeding and such, but im pretty sure the snakes can handle small amounts of inbreeding before issues start popping up like weaker immune systems. again, dont know much, but im trying haha.
We have two geneticists that have explained a few things here. I would recommend reading over what they have said/links that have been shared by one of them. Even with one generation, they will likely have an immune system that isn’t as good as a non-inbred snake, or run a higher risk of issues popping up. Especially if it is a sibling+sibling pairing. Genetics around inbreeding work the same for each animal from what I understand.
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Soo, this might be a dumb question but is line breeding a thing? Or does that create genetic hazards? How many generations, if so?
Yes it definitely is a thing. Back breeding is done quite often with various species to achieve a specific look. It’s hard to say how many generations it would take to see negative effects, but it’s best avoided when possible to minimize the risk of genetic defects.
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We actually had a long conversation not too long ago on the risks involved with repeated inbreeding - Breeding siblings together?
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Yeah, there’s also that thread about feeder inbreeding as well
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Uhh what new snake? Lol
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So I am wondering if I am going to inbreed ball pythons would it genetically affect the snake or would it cause some sort of defect?
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for a generation or two? no.
Is anything going to happen if you do more? probably not.
Does it increase the risk of issues? yes.
Should you continue after the first or second generation? probably not.
Have you read the whole thread above? it goes pretty into detail about it.
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