Descent of testicles.

I see. But I consider it preliminary for useless to discuss it, because my arguments would be the same and you know them.I suppose the discussion is over - if you or someone else wouldn't like to add or ask something.

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Obviously it is your custom to declare my logic as wrong. But I would reccomend you to have a look on some up to date phylogenetic tree. You would see that Monotremata, Marsupalia and Afrotheria makes a
part of tree where testicondy is most parsimonious solution. These are facts. And what's your point using strictly and correct logic?

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Of course you are confirming that I was correct to say that considering Afrotheria in isolation is not enough - the addition of monotremata is required.And even this does not get us to the point where we can say that neo-Darwinian theory is wrong or that orthogenesis is correct. Some subsidiary hypotheses have been falsified and that is all.I will take this opportunity to point out a fundamental error in your reasoning. If you want to deny that neo-Darwinian theory can plausibly account for an observation it is not a good idea to choose one where there is considerable doubt about relevant facts. The less that is known, the easier it is to construct a plausible hypothesis because known facts limit and constrain what is plausible. Words like "untestable" should be a great big warning sign in this regard because they shout out that the information that would allow us to rigourously check a hypothesis is not available.If you truly want to falsify a theory, the place to look is where the facts are most certain. That is where there is least room for the theory to escape. And even then it is difficult.

Just wanted to ask about one other point.Modern Theory of Evolution says that species evolve.I would think that examples such as descent of testicles would actually be a pretty strong supporting evidence that the Theory is correct and that Design or Direction are refuted.Since in the real world we do NOT see good ideas or effective features show up across species, it seems to me that the idea that species evolve independently is supported. We do not see external testicles on all species, instead we do see external testicles on fairly closely related species.What we seem to see when we look at lifeforms is that if some feature does not prevent reproduction, if the critter is good enough to get by, it does. If for any reason, some feature provides an advantage in reproduction it will soon out reproduce them critters lacking the feature and so become a dominate trait.BUT...nowhere in lifeforms do we find examples of design or direction such as we see in engineered objects.

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Anyone so limited that they can only spell a word one way is severely handicapped!

I'm still interested in teasing out the details of your alternative hypothesis if you are interested in doing so. Hopefully your arguments against the irreversible adaptation to sperm competition hypothesis would be different than your arguments against the testes cooling hypothesis? If not, then you're probably right - there's no point repeating them.

Unfortunatelly there is almost nothing I can add. It is a simple idea that during evolution the reproductive organs moved towards opposite end of that of the head, which represents individuality at most. So the head and reproductive organs in mammals are on the opposite ends of their bodies. I hit upon this interesting idea in the work of professor Adolf Portman, the Swiss zoologist. Adolf Portman wrote several books about evolution, many were published repeatedly in many editions. But only few of his work has been translated into English. Basically Adolf Portmann didn't dismissed natural selection as real evolutionary force. What he criticised most was the concept that "form follows fuction" which seems to me be also overcame in modern evolutionary thinking.His concept of coloration of animals as "self-representation" of species is non-darwinian approach to the phenomena, which is beyond the scope of this thread.

Ah - it's just a basic observation of body plans. As far as I am aware, this is well documented and discussed, perhaps you can dig up a paper on it for discussion sometime?I suppose, since you have nothing to add I will close with a barb - intended to spur the discussion forward if it is at all possible (that is to say, it isn't personal):

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I think that Modulous knows very well that I will defend my opinion in open discussion.

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And yet Remains undefended as far as I can tell. All you have done is established that there is no definitive evolutionary hypothesis for the natural history of the scrota that we can have any degree of confidence in. I don't see evidence for evolutionary forces standing above those in the consensus view of evolutionary theory (though obviously there is more to it than just mutation and natural selection) and I don't see how this relates to the observation you describe.If you do indeed have nothing to add, the previous comment can be seen as my conclusionary statement in this thread. If it motivates you into further defence of your position, all the better

From the history criticising professor Portmann's concept of descent of testicles.As far as I know professor Adolf Portmann's book Spirit and biology (Geist und Biologie) has never been translated into English. Yet professor Portmann's concept of descent of testicles was criticized heavily in neodarwinian journal Evolution published by Society for the Study of Evolution (can be find at jstor) in 1958.One of A.Portmann point was that birds having temperature more than 40 grad Celsius have no problem with spermatozoa.In the "THE EVOLUTIONARY SIGNIFICANCE OF THE SCROTUM" by Raymond Cowles we can read about cooling of birds spermatozoa: and Rodolfo Ruibal Uni California in the same journal:THE EVOLUTION OF THE SCROTUM Pretty convincing and self-confident neodarwinian stuff, isn't it? Yet the reality seems to be different than neodarwinists would like to have it:Determination of Testis Temperature Rhythms and Effects of Constant Light on Testicular Function in the Domestic Fowl (Gallus domesticus)Christine E. Beaupre, 3 ,5 Corinna J. Tressler,4 ,5 Steven J. Beaupr6,6 James L.M. Morgan,5 Walter G. Bottje,5
and John D. Kirby2,5Center of Excellence for Poultry Science, Departments of Poultry Sciences and Biological Sciences and authors ask: Page not found | BiolReprod Edited by MartinV, : No reason given.

So your conclusion is that 50 years ago some people were wrong about spermatogenesis in aves? It seems you have simply reverted us back to where we were in Message 43 where we had agreed the cooling hypothesis wasn't the best one given contemporary evidence and data.

Interesting are these words: "Portmann's unwillingness to accept the extensive experimental work...".

Yes, fascinating. This is a debate, remember?Edited by Modulous, : No reason given.