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Hybridising Tarantulas
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The other day one of our members summed up my thoughts on hybridising absolutely perfectly so I will quote him here and lock and sticky it :thumbsup:
phran said:
'personally, science works best for me.....''Science flies you to the moon, religion flies you into buildings''
just some notes on hybridisation conservation etc.
Something I think everybody should read is the various species concepts, there's even a wikipedia page on it. Apart from being interesting, it gives anybody valuable backround on hybridisation/taxonomy etc.
First off, our ideas about conservation, is flawed in the manner that we want to preserve each and every species exactly as it is. Which is good when it comes to not exploiting/hunting species to extinction. However hybridisation is a natural process, which fuels gene flow, and promotes evolution. We tend to adopt the creationalist perspective that the animals we know currently, are fixed species that we should preserve forever.
The species we know are but a 'photograph'' of a moment in the process of adaptation, thus trying to preserve them in their exact form, is a artificial, and in itself a form of pollution.
All this being said, the t's we keep in our collections, are removed from the natural scenarios, hence there is no need for them to adapt, hence no need for gene flow and thus no need for hybridisation.
so in short hybridisation is a nessesary process in nature, but totally unessesary in the hobby.
Further, personally i don't see the point in doing ''research'' on hybridisation, as little scientific information is to be gained from it,,,, hybridisation, in the hobby, is in short, casual experimentation to gain new variaties of asthetically pleasing pets. that's it.'
And then I'd also like too quote a member on the BTS forum with regards to inbreeding....
'Nick L said:
I would just make a few points generally about inbreeding (i.e. not specifically related to Ts)…
1. Inbreeding ‘in nature’ is widespread and common. Indeed it is a consequence of one of the main mechanisms of speciation – look up ‘Founder Principle/Effect/Theory’.
2. Is it ‘bad’? Well ask any group of geneticists or evolutionary biologists and you wont get a consensus of opinion because the research that has been done is expansive and conflicting. For every paper that you’d care to site I’ll find you a contradictory one (I’m talking of peer reviewed ‘scientific’ papers in mainstream journals here). There is quite convincing evidence that it can be beneficial in the long-term – deleterious gene effects appear to be more common in first few generations; such individuals are quickly ‘weeded out’ by natural selection leaving in subsequent generations a genetically ‘fitter’ population compared to an outbred population (deleterious recessive genes are effectively removed from the population genome in the first few generations; thereafter even the incidence of deleterious gene expression is lower compared to a ‘normal’ outbred population i.e. they are ‘fitter’ than a ‘normal’ population.).
3. The deleterious genetic effects that can occur with inbreeding tend to be ‘catastrophic’ i.e. the embryo fails to grow at all or dies before it has fully developed so in the case of Ts most of the negative effects will only be apparent within the egg sac. The slings that emerge are likely to be as ‘healthy’ as any.
4. ‘Culling’ strikes me as an inherently bad idea. As has been pointed out in other posts, on what criteria do you do it? Indeed how do you know how to play ‘God’ by imitating natural selection? Natural selection is not a ‘guiding hand’ – there is no direction, no ultimate goal, it chops and changes and is constantly going on. Keeping Ts in captivity is subjecting them to a variant of ‘natural selection’ anyway (remember all of those unexplained deaths?) – if they are surviving your husbandry (and are therefore ‘adapted to their environment’) who are you to say that particular individuals should be culled because of some other criteria that you’ve decided upon – if you are aiming for a genetically ‘healthy’ population then you should be MAINTAINING that variability NOT reducing it by culling.
5. A more specific point here…
Originally Posted by Phil Rea
In my humble opinion, you cannot compare reproduction of spiders (apart from the inherent biological processes within reproduction and genetics, such as meiosis, the production of gametes etc.) with the reproduction of more complex organisms.
Why not? There is no difference. Sexual reproduction is the SAME though-out; the ways in which it is achieved is the only aspect that you cannot compare and that is irrelevant here. How are you defining ‘complex’? There are many known examples where ‘simpler’ animals have far more genetic material than more ‘complex’ ones such as us humans. More is know specifically about the genetics/reproduction of the ‘simple’ fruit-fly than anything else but because there is no inherent difference in the mechanics of it all by inference this knowledge can be applied to humans.
Theraphosids are going to be no different to fruit flies or humans in terms of genetic mechanisms. No one is ever going to study the genetics of Ts (DNA sequencing for taxonomic purposes excepted) because the generation length is just too long – the favoured tools (species) for the geneticist have very short generation times so that results can be quickly seen. So, the favoured choices are fruit-flies, zebra fish and mice – if the mechanisms weren’t comparable to humans I doubt we’d be studying them to the degree that we are.
I’ll leave it there with my comments but would just say that this topic generally (not just in relation to Ts) is one that is awash with misconception and misinformation in the public domain. However, you wont get a definitive answer from the scientific world either! Personally I have no problem with it.
Nick'
And you can go read through the whole very interesting thread
here
You can take an Aphonopelma to crickets but you can't make it eat!
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