Iamconstantlyhappy
Arachnoknight
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- Feb 4, 2020
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Is there any issue with breeding ts from same sack (Inbreeding) as in other creatures? Is it better to breed from different sacks for genetic diversity. Is this a retarded question? 
Breeding from same sack
- Thread starter Iamconstantlyhappy
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That's a perfectly good question.
One issue is that the male tarantulas will mature [and probably die] before their sisters reach maturity. You can deal with that problem by "slowing down" the males -- keeping them cooler, feeding them less, etc.
About genetic diversity:
Lab rats, lab mice, Drosophila, domestic crickets and many other animals are routinely inbred with no trouble, but these lines are not the wild strains of the species. The genetic defects that could cause problems have been bred out of these lines. Don't get the idea that they are perfect superrats, supermice, superflies, or supercrickets; they're not - they are much slower and stupider than their wild counterparts. It's useful in the lab to work with "isogenic" strains of animals, those that have the same genetic background, to avoid confounding experimental results introduced by genetic variability.
I have also inbred [somewhat] wild strains of mice and gerbils, and the genetic defects become obvious within a couple of generations -- misshapen ears, shortened tails, some kinds of limb deformities or joint problems, infertility, and generally poor health.
Humans would suffer the same fate. Don't marry your sister!
For spiders, inbreeding has worked. Whether breeding genetically distant specimens would be better, I think that's unknown, but a real possibility.
The factors that could allow a species to be inbred successfully are:
1.) A long history of inbreeding within a particular strain, as with the lab animals mentioned above, which have been bred selecting only the most functional offspring for many generations.
2.) A "streamlined" genome: having a high reproduction rate that is negatively affected by genome size. Errors and added junk are selected out quickly.
3.) r-selected species, those that survive with the reproductive strategy of producing very many offspring, with the reality that most offspring will not survive to adulthood.
Considering tarantulas:
Factor #1: Mostly NO, but that may change over the long run within the hobby.
Factor #2: NO, actually spider genomes are much like ours, with lots of introns, lots of junk, usually a slightly greater number of genes than we have. Don't allow yourself to believe that the "higher" the life form, the greater the number of genes. Flowering plants have more genes than any animal. No need to cry about it: I promise you that we are not inferior!
Factor #3: YES. I hereby challenge the world's toughest farming country woman to pop out as many babies as our tarantulas do. If she can manage > 1000 babies per year, then I will buy cute little baby UGGs boots for all of her children.
So the conclusion: Inbreeding spiders does work, but it may not be optimal.
One issue is that the male tarantulas will mature [and probably die] before their sisters reach maturity. You can deal with that problem by "slowing down" the males -- keeping them cooler, feeding them less, etc.
About genetic diversity:
Lab rats, lab mice, Drosophila, domestic crickets and many other animals are routinely inbred with no trouble, but these lines are not the wild strains of the species. The genetic defects that could cause problems have been bred out of these lines. Don't get the idea that they are perfect superrats, supermice, superflies, or supercrickets; they're not - they are much slower and stupider than their wild counterparts. It's useful in the lab to work with "isogenic" strains of animals, those that have the same genetic background, to avoid confounding experimental results introduced by genetic variability.
I have also inbred [somewhat] wild strains of mice and gerbils, and the genetic defects become obvious within a couple of generations -- misshapen ears, shortened tails, some kinds of limb deformities or joint problems, infertility, and generally poor health.
Humans would suffer the same fate. Don't marry your sister!
For spiders, inbreeding has worked. Whether breeding genetically distant specimens would be better, I think that's unknown, but a real possibility.
The factors that could allow a species to be inbred successfully are:
1.) A long history of inbreeding within a particular strain, as with the lab animals mentioned above, which have been bred selecting only the most functional offspring for many generations.
2.) A "streamlined" genome: having a high reproduction rate that is negatively affected by genome size. Errors and added junk are selected out quickly.
3.) r-selected species, those that survive with the reproductive strategy of producing very many offspring, with the reality that most offspring will not survive to adulthood.
Considering tarantulas:
Factor #1: Mostly NO, but that may change over the long run within the hobby.
Factor #2: NO, actually spider genomes are much like ours, with lots of introns, lots of junk, usually a slightly greater number of genes than we have. Don't allow yourself to believe that the "higher" the life form, the greater the number of genes. Flowering plants have more genes than any animal. No need to cry about it: I promise you that we are not inferior!
Factor #3: YES. I hereby challenge the world's toughest farming country woman to pop out as many babies as our tarantulas do. If she can manage > 1000 babies per year, then I will buy cute little baby UGGs boots for all of her children.
So the conclusion: Inbreeding spiders does work, but it may not be optimal.
Last edited:
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Genetic diversity is typically better than FrankenTs, or Frankenmammals
Frogdaddy
Arachnoprince
- Joined
- Nov 13, 2019
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- 1,069
Isn't inbreeding less of a concern with Ts as you see so many people seeking a MM or MF to mate with their specimen? That would indicate to me that the two mating spiders are not from the same sac and probably unrelated.
I could see where in the future after many generations of captive bred T's new animals would have to be imported and bred just to increase genetic diversity so we don't have a bottle neck.
I could see where in the future after many generations of captive bred T's new animals would have to be imported and bred just to increase genetic diversity so we don't have a bottle neck.