More Catt Name Changes

[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.

[Rosim_in_BR]

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.

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.

[Jan Pahl]

Genetic clocks are still on diapers, but even if Van den Berg et col recognize that fact specially when they have to classify bellow sub-tribes and specially inside alliance, they persist on give us "incontrovertible" out-puts at genera level. The thing gets even more bizarre the moment we realize that even if we know the actual studies are not precise specially at genera level, we are still happy to put away important things like morphology, ecology and plant behaviour to understand relationships and make brand-new "reclassification's".

People, let me put things Cristal clear, we can't do a stable classification if we trust on a tool that still needs to be calibrated. The problem is not the numbers of genetic markers they are using, the problem is that they only have a guess about the rate of mutation over time and the standard deviations associated to that rate... ergo, the moment that very related genera enters in a study, them studies end with scramble egg conclusions like super-Cattleya or the defunct mega-sopronitis.

I not implying that all inside those studies are imprecise, for example, thank's to them we know that Guarianthe is not Cattleya and that Brazilian Laelias have nothing to do with mexican ones, but come on, not all the findings have the same level of confidence, specially if a group of orchids was recently split from another ancestral one like the case of schomburgkia and mexican laelias, the case of Rhyncholaelia and Guarianthe, or the case of Brassavola and Cattleya.

In my case I not going to accept this super Cattleya genus because I know is not going to last more than 10 years maximum... Why scientist don't wait to have more precise genetic markers an just them decide to move genera?, I don't know... I simply prefer to deal for a time with genera that I know are wrong, than deal with new genera that I know in just years are going to be again wrong ...please people more stability needed first.

Sorry for my english
Jan

[orchideric]

Just a note to Steve.

singular = genus

plural = genera

Similarly,

singular and plural = species

Think, one sheep, two sheep.

Hope that helps, Eric

[Jan Pahl]

Originally Posted by Rosim_in_BR

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.

Rosim sorry to interrupt you and maitaman, but I have to quote a very significant misunderstanding very easy to find outside countries with many examples of large unifoliate Cattleyas like Venezuela and Colombia. I mean, say that C. lueddemanniana is just a subspecies of C. labiata is like say a jaguar is a subspecies of the leopard because both are large cats and both have yellow coats with dotted fur.

I agree that for example, even if a mossiae and a percivaliana are quite different most of the time, sometimes is possible to find specimens that very much resembles the other species one way or the other, something that is not necessarily a characteristic of “artifact species” (for example "testosterone" Coyotes that resembles "small" Wolves).

What I completely agree with Rosim point of view is that inside unifoliate Cattleyas, species status is quite unstable in more than one complex of species but NOT among all unifoliates plotted “against” C. labiata, for example; beneath labiata, warneri, jenmani and gaskelliana group, beneath dowiana and aurea pair, or even but in a lesser degree inside trianae, schroderae and quadricolor group, specially between trianae and quadricolor.

I also agree that botanist and orchid collectors tend to over estimate orchid differences and call it species and not subspecies with to much easiness, forgetting that inside collections, subspecies means just ad an ssp between species and subspecies name in a trinomial name on the label… but we can’t react to this odd behaviour of calling everything a species putting ourselves in the complete opposite and also very wrong side of the balance saying that a Wolf and a Coyote are the same species… each orchid genera need years of training seeing many examples to actually realize that even if two or more organisms look very alike, they also have many differences not only in phenotipe, but also in growing habits and in ecology.

Lets end with a example… one way to see that unifoliates are indeed true species is seeing by the eyes of introgression, to name one example; C. mossiae sometimes forms a natural hybrid with percivaliana, and also sometimes forms a natural hybrid with lueddemanniana, but why both hybrids are difficult to find in nature even if sometimes they form smal colonies?, and in a very first place, why genetic interchange are not equaling over time the three populations at least at the confluence area or near it?... well the answer is very simple, because natural selection favours “pure mossiaes, percivalianas and lueddemannianas” over hybrid plants even in places where mossiae and percivaliana or mossiae and lueddemannniana lives as neighbours.

Regards
Jan

[maitaman]

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.

[Jan Pahl]

Yes, I completely agree in that matter, specially when differences (even if they are not necessarily "minimal") are to much unstable than expected between two different species.

Another kind of mistake is possible to trace on poor botanical research when the data is available but not analyzed.... for instance, RHS recognize Catasetum imperial has a different species than pileatum, but that is not true is available data is correct. Pierre Couret made many years ago very good photographic examples of the "imperial complex" that run from odd macrocarpums, pass clearly recognizable tapiriceps, and end's in the imperial forms.

what botanist found as "enough differences" to segregate it from pileatum turn to be just influences from macrocarpum (from x tapiriceps introgression) on small differences on the shape of the pseudobulbs, color macrocarpum stains on it, the variations on the aperture of the flower pileum, and off course the color of the flowers.

The only way to not consider imperial forms has true pileatum, is because is considered has true tapiriceps, even if it only have 1 or 2 % of macrocarpum genes on on it.

[Jan Pahl]

Well I end to read all contributions and I only have to make one last one.

genetic clocks are not a quantitative precise way to “measures” the “amount” of divergence that two or more species need between each other in order to obtain some “botanical status”. On the contrary, is a way to show when in chronological time two or more groups diverged from each other based on number of accumulated mutations over time show on one or more genetic markers. This way is possible to see if two or more groups are monophyletic (descend from the same single ancestor) or polyphyletic (have various ancestors). That last "measure" (monophyletic against polyphyletic) it's what drives geneticist to conclude split or join taxa, not the amount of "genetic" divergence since very recently split genera obviously would have less divergences than more old ones and so on....

The amount of accumulatd mutations (genetic clock) only say when and where in the past the taxa split from the main branch, but not say anything about some "theoretical" amount of mutations needed to obtain "genus" status. For instance, crocodile species have much more inter-species divergences than ape species simply because crocodiles species appeared long time before than Apes. If we measure for example the species amount of variability between related crocodiles and we use that criteria of “species divergence” in Apes, we are going to find ourselves very soon with odd conclusions like chimpanzees and humans are the same species. The same thing with orchids, specially with new born genera.

Decisions like join almost all Cattleya alliance has a single genus is made not because there is "no enough" genetic difference between Cattleya and Sophronitis, but because the genetic clock used is not enough accurate to clearly distinguish with the required accuracy new genera like like Cattleya or Brassavola need... that's why problematic "jumping" species like C. maxima still show even if they repeat studies.

The solution yet to come is simple, more precise markers that are sensible to show trends on small amounts of time between species splitings.

[RoyalOrchids]

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?

[ocaso07]

I'll keep my labels and add changes on other side.But... oh thank god!! woo hoo