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08-08-2008, 02:29 PM
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The problem (as I see it) with DNA classification is that the position of dominant characteristics is sometimes as important as the having or lack of the specific gene. A weak marker in a dominant position will have far more effect on the plant than a strong marker in a low influence position.
I personally think many so-called species are merely varieties of the same thing, with strong argument in Epidendrums, catasetums, etc. Most divergent catasetum "species" found here are really sub-species (varieties) of integerinium (IMHO) as many Epidendrum are sub-species of diforme, and almost all anacheilum are sub-species of the old radians (now radiatum?) or fragrans. The supposed differences are in dominant/non-dominant positioning on the chains.
A lot of the problems could be solved by calling a sub-species a sub-species - but that has its own bewares.
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08-08-2008, 10:14 PM
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Quote:
Originally Posted by maitaman
The problem (as I see it) with DNA classification is that the position of dominant characteristics is sometimes as important as the having or lack of the specific gene. A weak marker in a dominant position will have far more effect on the plant than a strong marker in a low influence position.
I personally think many so-called species are merely varieties of the same thing, with strong argument in Epidendrums, catasetums, etc. Most divergent catasetum "species" found here are really sub-species (varieties) of integerinium (IMHO) as many Epidendrum are sub-species of diforme, and almost all anacheilum are sub-species of the old radians (now radiatum?) or fragrans. The supposed differences are in dominant/non-dominant positioning on the chains.
A lot of the problems could be solved by calling a sub-species a sub-species - but that has its own bewares.
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It makes sense and is perfectly valid. Such line of thinking also leads to the conclusion, just to take an easy example, that all labiate Cattleyas (waneri, lueddemanniana, percivaliana, mossiae etc) are merely variations of Cattleya labiata Lindl., or sub-species at most. Under a strictly scientific point of view that's exactly what they are.
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10-30-2008, 12:25 PM
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Just a note to Steve.
singular = genus
plural = genera
Similarly,
singular and plural = species
Think, one sheep, two sheep.
Hope that helps, Eric
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11-01-2008, 11:28 AM
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I agree that labiate catts are probably several basic species, not all sub-species. My arguments are more on the line of things like Cstm. integerinum with such minor variations that it's almost ludicrous to call them separate species. If it has lots of spots in the male flower on an identical plant it is maculatum. If the spots are slightly smaller it is oerstedii. If there is a slight tendency to ciliate the upper lip it is discolor and if not viridiflavum.
My point is these things are the same markers, just in slightly different positions of dominant/recessive influence. Same with Epi. diforme and six or seven others where altitude may well be the influence stressor.
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05-27-2009, 09:10 PM
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Thanks again for this great thread, everyone. I would never have the opportunity to eavesdrop on a conversation like this anywhere but here on the OB. You have all given me much to think about and represent many different perspectives. I hope it continues.
But here is my question: What do we scientists and hobbyists do? The RHS database has already changed. Is it official yet? If it is, do we just ingnore it? (like some did when they lumped those L. into S.) Do we change tags? Did you change tags last time?
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05-27-2009, 09:17 PM
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I'll keep my labels and add changes on other side.But ... oh thank god!! woo hoo
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06-08-2009, 08:31 AM
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I am a scientist and engineer (materials, not biological stuff), so the DNA sequencing seems to be a good idea, but as has been mentioned, just how far does one go in - and upon what basis - in splitting genera and species?
Take a look at people - there are a lot of genetic variations out there, yet we're all Homo sapiens. The fact that genetics reveals relationships among the various "catts" is of no surprise at all.
Truthfully, I have not followed the reclassification that closely, as the taxonomists are wont to just change it all again, but wouldn't it be easier if one focused on plant form, pollinia count, and that sort of thing, for separating/combining genera?
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06-08-2009, 09:01 AM
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Quote:
Originally Posted by Ray
.......
Truthfully, I have not followed the reclassification that closely, as the taxonomists are wont to just change it all again, but wouldn't it be easier if one focused on plant form, pollinia count, and that sort of thing, for separating/combining genera?
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Agree. Especially because, after all, such things like plant form, pollinia count and form, flower form, colors and so on... are all expressions of the genes inside... A particular species has two leaves because there's one or a set of genes governing this characteristic. In other words, morphology is nothing more than the visual expression of the genes inside the plant and has been the basis for the traditional taxonomy until now... and in my opinion with all the merits. I am not against using the DNA research for a better understanding of the relationships between plants. What seems to be excessive is to forget everything else and throw centuries of serious research in the trashcan.
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06-08-2009, 11:05 AM
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So again, what will you do with your tags? Will you reject/accept these changes all together, or will you pick and choose those with which you agree? Which re-classifications will you accept? Did you accept the last changes? If not, do we take action or protest in some way? Do nothing?
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06-08-2009, 02:00 PM
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Quote:
Originally Posted by RoyalOrchids
So again, what will you do with your tags? Will you reject/accept these changes all together, or will you pick and choose those with which you agree? Which re-classifications will you accept? Did you accept the last changes? If not, do we take action or protest in some way? Do nothing?
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It is a hard question to answer, Royal! Anyway, I can say that I am not changing my tags when the plants involved are well-known plants in the whole world, like Laelias, Sophros and Cattleyas, Maxillarias, Oncidiums. It is not wrong and you cannot be punished in a show or judging if you use Cattleya bicolor instead of Cattleya dichroma as they want now. Both are synonyms and perfectly acceptable.
I am not changing my tags because I am sure these names are going to change again and again, based on new DNA studies or new methods or whatever. Less than a decade ago the large flowered Laelias were Laelias, became Sophronitis, then Hadrolaelias, then Brasilaelias and now Cattleyas. It is just a matter of time for them to become Brassavolas for the lumpers or something else for the splitters.
Researchers don't give a dime for us orchid lovers and we don't have how to protest. They don’t hear any of our arguments because in their opinion, once we are not scientists, our opinions are just this, opinions of people who collect plants. They believe they are making the most advanced science and enlarging the human understanding by using these still very questionable DNA studies forgetting that these techniques and methods are still very new and need time to mature. In my humble opinion, the best way in our days would be to combine morphology and DNA analysis to provide a more stable nomenclature. Unfortunately, they elected DNA sequencing as the new god for these problems of elucidating relationship between groups of plants and simply forgot the morphology. They simply discarded this important tool as if it were completely useless. I think that if we say the word 'Morphology' in a conversation with these DNA researchers they will have a heart attack before us!
Well, everything points out to hard times ahead before we can see some light at the end of the tunnel.
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