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Post by lucanidae25 on Jul 7, 2011 6:51:19 GMT -8
My point of view is very simple, finding a very big telodont is the same as finding a 7 feet human male in this world.
Probability is the biggest factor and the rest are: genetic+ nutrition+ environmental and just a bit of luck. Luck is the probability part that can't be explain, only one of so many number of larvae under the same conditions would be a very big telodont. I don't think anyone can control probability but we all wish we could though. hahaha ;D
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Post by thanos on Jul 7, 2011 21:12:03 GMT -8
Nothing happens by luck in biology. The size of the body parts that gets an adult specimen of a species depends on a combination of these factors: genetic,nutritional,environmental/climatic(and evolution of trait proportion due to environmental etc changes,for survival and adaptation of species) ,hormonic.
With the experiments of the above work,it was proved scientifically that the sizes can be controlled hormonically+nutritionally. It is just not easy,and must be done with the right scientific knowledge. This seems to have been achieved by some very good breeders/scientists of Lucanidae/Dynastes etc who,using very suitable/ideal nutrition and/or hormones correctly,they have achieved record sizes of bred specimens.
Don't forget also the so many fruits that become bigger than in natural conditions,by using hormones,and not by luck.
(Now,the so many examples of bred butterflies that are smaller than the wild ones,is due to not providing 100% the right nutrition/conditions/space/temperature/care to the larvae during breeding,as the ones they have in nature).
Thanos
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Post by lucanidae25 on Jul 7, 2011 21:58:36 GMT -8
Probability is the combinations of gene from both parents, that is something we can't cantrol ie. genders. I've done Lucanidae breeding myself too. I can have the biggest parents and give them the best of everything: nutrition/conditions/space/temperature/care to the larvae. Every single specimen would be in different sizes, no different to the wild. I only noticed there can only be one biggest male in every generation, not every single specimen is the same size. That is probability.
Probability is when everything comes together: the right gene combinations and nutrition/conditions/space/temperature/care....
The only way you can garantine every single specimen is the biggest telodont is cloning.
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Post by bichos on Jul 7, 2011 22:03:19 GMT -8
I would not totally dismiss luck as a factor, you can also define it as chance. Evolution happens strictly by chance/luck when a species mutates and that characteristic is favourable in terms of reproduction and is passed on to the next generation, it is stored chemically within the genetic code. Through natural selection, characteristics like big mandibles evolve and the only way this happens is through mutations within the genetic code and it takes many many generations and yes chance/luck.
Obviously we are exposed to the whole picture of nutrition, temperature and other environmental factors directly influencing an individuals phenotypic expression. And yes Thanos is right without the right nutrition etc an individuals genes cannot and often do not fully express themselves and what you then get is small individuals. Without the right conditions there is an inability for species' to procuce the teleodont form and I think Ray means to say that often through luck all the factors come together to produce an exceptional teleodont which is head and shoulders above the rest.
I think it is favourable for a species to have the ability to emerge as amphiodonts-mesodonts and teledonts as the different morphs can play different roles in nature, with the ultimate goal being to pass its genes on, whether it be by a quick mating or a mating followed by some protection to the female that only a teleodont can provide...
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Post by africaone on Jul 7, 2011 23:39:22 GMT -8
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Post by africaone on Jul 8, 2011 4:07:59 GMT -8
I read the paper referenced by thanos ! nice one and helpful. It provides scientific answers to some points and helps the discussion. Of course it is very pointed and don't answer completely to the question (that seems very complicate !). I found another one interesting, more behavioural ! at www.cebc.cnrs.fr/publipdf/2005/LRETV60.pdfThierry |
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Post by thanos on Jul 8, 2011 14:00:30 GMT -8
I find this article quite obvious. I have observed in nature hundreds of L.cervus,and quite many 'couples' of fighting males,and almost all the times the fighting males were telodonts(1 big with one medium-sized telodont, or 2 medium-sized telodonts of about the same size). I barely remember having seen 2 small males(small mesodonts or mesamphiodonts) in fight,or a big telodont with a small mesodont(the small avoids the big and is not aggressive to him,except if he(the smaller) is quite close to his(the bigger's) size) . So I had already understood that the bigger males are the most aggressive and that the fighting behaviour depends on size.
Thanos
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Post by jackblack on Jul 11, 2011 4:28:21 GMT -8
My odd Lamprima I bred out had a minor male mandible and a major teledonte mandible on the opposite side , no not a gynandromorph sadly , as I mentioned I have seen several specimens in old collections like this and met the collectors now passed away , so nutrients may have had something to do with this , years ago when a number of such specimens were collected land clearing was going on forest was knocked down so less larva between logs more nutrients were more available till numbers bred up , more competetion for food , then beetles got smaller parasites were more rampant , habitat was reduced then so were the logs available for breeding ,specimens got smaller , but ever now and then the teledonte males are still there but never in numbers .But major males can still be found big bodies but not with the deer like major antlers which seem to be common in parts of PNG , I lived there as a boy and up in the mountains at Erumai Lamprima /Neolamprima occured but there in the high altitude I never saw a major teledonte male only green males of normal size males usually sitting on the side of tree trunks but I wasn`t a beetle collector in those days just an observer of nature as I grew up amongst it .
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Post by africaone on Jul 11, 2011 6:39:06 GMT -8
this asymetry in mandibules sound like a genetic affair ! may be there is a need of a predisposition of having big mandibules ...  and that ammount of JH is not enough ! |
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Post by lucanidae25 on Jul 11, 2011 16:58:16 GMT -8
Lucanidae is no different to a group of lions and gorillas in Africa. There can only be one biggest male in a group. It's natural selection ansuring only the biggest gets to pass on the gene. it's all probability and ratio, 1:number? or 1/number? what ever that ratio is only one out of so many males would be the biggest.
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Post by lucanidae25 on Jul 20, 2011 19:57:20 GMT -8
It's so hard to find a very big Prosopocoilus confucius around 100mm from China now a day and I'm wandering why. Maybe removing the biggest males from the populations really effects the next generations by over collecting from the wild??? I've seen it happening with each generation from the wild is getting smaller every year in China from the same location. I know it has nothing to do with the environment. The environments havn't changed.  Has any one seen a P. confucius bigger than 100mm recently? The last time I got a 100mm was in 2000. |
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poisonarrow
Full Member
Looking for fellow entomologists in the SF Bay area
Posts: 109
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Post by poisonarrow on Jul 26, 2011 23:35:02 GMT -8
Hey, just saw this now. Thanks Thanos for the link.
I just came across this, as I wasn't sure any more whether I had named these beetles correctly and wanted to double check. I am quite busy these days, also with re-launching the website. Will update you once it's done :-)
Regarding the 100mm P. confucius. I would suggest you to catch a few females and give them to one of our Japanese breeder friends. If they can only get out small males, we at least have a clue that giant size in this species is partly inherited.
Cheers
ben
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