This blog entry is a reply to a couple replies in this forum thread... A Different Way To Protect The Ghost Orchid
lotis146, good lord is right! You're on the 7th page? This is only the second page for me. Either you like clicking page numbers and waiting for pages to load...or nobody told you that you that you can change your settings in order to view more posts per page.
tropterrarium, you say that you can parse this passage...
Based on future projection of their ecological niche, and given that conditions suitable for these hybrid zones will exist, the hybrid zones can therefore be seen as a source of raw material for natural adaptive change [61,62]. In this light, the definition of species should better focus on traits that lead to adaptation and conservation efforts should be targeted towards evolutionary processes that generate taxonomic biodiversity instead of preserving the taxonomic entities beyond these processes . Although this strategy cannot be applied to all organisms, it certainly provides a good framework for determining evolutionarily important units [63,64] that are worthy of protection and management in species with complex reticulate scenarios, such as those in the present investigation. - Marques et al, Multiple hybridization events, polyploidy and low postmating isolation entangle the evolution of neotropical species of Epidendrum (Orchidaceae)...but then you didn't actually parse it for those of us who don't have PhDs! What a knowledge tease! Let me quote Holbo's paraphrase of Socrates...
You could have been much more concise, Euthyphro, if you wanted to, by answering the main part of my question. You're not exactly dying to teach me - that much is clear. You were just on the point of doing so, but you turned aside. If you had given the answer, I would already be well versed in holiness, thanks to you. But as it is, the lover of inquiry must chase after his beloved, wherever he may lead him.Do I have to beg you to translate Marques' passage into ordinary English? Maybe a bribe would help? How many Oberonias would it take? Let me know how difficult it would be for you to translate that passage for those of us who are interested in learning more about evolution and biology.
If you argue that the two original lineages persist with the new hybrid, then that leads to narrowing of niches, and more specialization. More specialized taxa have a greater probability (or Popperian propensity, if you wish) for extinction (plenty of evidence in fossil record). Accordingly, you may get unintentional consequences of reduced biodiversity over evolutionary/geological time scales. - tropterrariumThis is kinda funny. You're arguing that introducing funalis and lindenii x funalis into Southern Florida is likely to result in a dangerous situation. But the dangerous situation you described (a taxa that's so specialized that it has a greater probability for extinction) is identical to the situation that currently exists. Did you not realize that Dendrophylax lindenii is in danger of extinction because it's a very specialized taxa that occupies a very narrow ecological niche?
Basically we're holding a fragile bird in our hands and I'm wondering whether we should try crossing it with a robust bird in the bush. Your argument against doing so is that it's likely that we'd end up with a fragile bird in our hands. According to you, the worst case scenario is identical to the current scenario.
What's the best case scenario?
Rates of evolution are recognized to be very variable, and exceptionally rapid rates tend to accompany the shift from one adaptive norm to another which is usually required for the major evolutionary advances (Simpson, 1953). The rate which prevails at any one time is a function of the genetic variability of the evolving population as it interacts with the prevailing environment. For the major advances to take place, therefore, a population with a high degree of genetic variability must be placed in an environment which is rapidly changing, and which offers to the population new ecological niches to which it can become adapted. Because of the slow rates at which it occurs, mutation can never provide by itself enough variability at any one time to fulfill such conditions. Genetic recombination must, therefore, be the major source of such variability, so that evolutionary lines most likely to take advantage of a changing environment are those in which recombination is raised to a maximum. This is accomplished by mass hybridization between populations having different adaptive norms. - G. Ledyard Stebbins, The Role of Hybridization in EvolutionI don't know, but that sure sounds relevant to herclivation. Then again, as so many have been so quick to point out, my grasp of basic biology is tenuous at best.
Maybe it would help to use that passage to make a check list...
- Does Florida have a rapidly changing environment? Check
- Are there many new ecological niches available? Check
- Does lindenii have a low degree of genetic variability? Check
- Do lindenii and funalis have different adaptive norms? Check
But I did, however, have a chance to look through this slightly less prehistoric book...The Orchids - Scientific Studies (1974) which is where I found this...
However, selfing is rare in orchids and this brings us back to the question of the role of hybridization in speciation. A general review of the problem may help us to hypothesize on the orchid situation. Hybrids appear to be exceedingly uncommon among rain-forest trees, and the most likely explanation is that there is strong selective pressure against hybridization (Ashton, 1969). On the other hand, few tropical forest species are able to colonize cleared sites, while a number of examples exist of successful colonization of such areas by hybrids. (As, for example, hybrids referred to by van Steenis, 1969, and Hevea Aubl., by Seibert and Baldwin, as quoted by Stebbins, 1950, p. 264) The reason for this is that plants in a more or less undisturbed habitat are adapted to that habitat or they would not have survived there. Genetic recombination - as well as mutation - simply by being different gives rise to a great preponderance of genotypes not adapted to the environment. It is also probable that species adaptation is based to a large extent upon epistatic gene interaction (i.e., interaction at different loci), in which case the complex interacting system will very easily be upset by hybridization (Mayr, 1969; Stebbins, 1969). Rarely, recombination may give rise to plants adapted to a different environment, hence the survival of hybrids perhaps at points of natural environmental transition and most certainly at points where disturbance has led to removal of most competitors as well as change in the nonbiotic environment. More rarely still, recombinations may give rise to individuals better adapted to the same environment inhabited by the parents (i.e., having superior competitive adaptability). - William W. Sanford, The Ecology of OrchidsHow convenient. Sanford took Stebbins' theory and applied it to the orchid family. Again, it sure sounds like this provides a reasonably solid theoretical foundation for herclivation.
Going back to your maths...I think part of the problem is that you're using terrestrial maths rather than epiphytic maths. Don't worry, you're really not alone.
Here's your terrestrial maths...
1 lindenii + 1 funalis + 1 funalis x lindenii = 1 (or less) Dendrophylax in Florida
Here's the same equation but with epiphytic maths...
1 lindenii + 1 funalis + 1 funalis x lindenii = 3 (or more) Dendrophylax in Florida
Why's the answer so different? It's because epiphytic maths have infinitely more ecological niches (aka microhabitats, microsites) than terrestrial maths...
Germination rates in the field vary greatly between microsites. Tree crowns consist of a heterogeneous mosaic of microhabitats resulting from a complex combination of biotic and abiotic variables (Benzing 1978, 2000; Callaway et al. 2002; Hietz & Briones 1998; Madison 1977; Scheffknecht et al. 2012; Winkler et al. 2005). Within the canopy, radiation, temperature, wind velocity, and water and nutrient availability vary spatiotemporally, creating microclimatic gradients that may differentially affect the germination of different epiphytic species (Benzing 1978; Hietz & Briones 1998; Zotz & Andrade 2002). These variables change from one phorophyte to another, depending on their height, crown size and shape, leaf habit, bark characteristics (texture, stability and water retention capacity), branch thickness, position in the canopy, the presence of allelopathic compounds or other minerals washed from the phorophyte, i.e., lixiviates (Bennett 1986; Benzing 1978, 1990; Callaway et al. 2002; Castro et al. 1999; Frei et al. 1972; Mehltreter et al. 2005). - Mondragon et al, Population Ecology of Epiphytic Angiosperms: A ReviewWith epiphytic orchids, a single seed pod can release a million dust-like seeds that the wind can transport to a gazillion possible niches. Most niches won't be suitable for most seeds...but because there's so many seeds and no two are exactly alike...and there's so many niches and no two are exactly alike...the boundary of what is, and isn't, suitable is constantly being pushed. Epiphytic orchids are really good at hedging their bets...which is why they are the poster plant for adaptive radiation. A long time ago the seed from an epiphytic orchid landed in some guy's ear. A second later he had an epiphany and wrote down the infinite monkey theorem. Coincidence? I think not. This is also where the word "epiphany" comes from. How many millions of epiphytic orchids are churning out entirely new combinations of traits? Well, there are around 20,000 species of epiphytic orchids...so if we multiply that by 2,000 plants per species (one estimate of the population size of D. lindenii in Florida) we get a very conservative estimate of 40,000,000 individual epiphytic orchids. That's a lot of busy monkeys. It shouldn't be a surprise that their habitats range from dripping wet cloudforests to deserts where they grow on cactus and succulents.
As it stands, I've had absolutely no success teaching epiphytic maths to critics of herclivation. The triple decker bus analogy completely failed to help them appreciate that, when it comes to arboreal microhabitats, zero sum situations are the exception rather than the rule. There are plenty of seats that still aren't taken. Either epiphytic maths are supremely difficult to learn or I'm a horrible teacher or...
Let me try another analogy. In the movie a Beautiful Mind, there's a scene where the Nobel Prize winning liberal economist John Nash is hanging out at a bar with his buddies. A blonde walks in with her brunette friends. All of Nash's buddies see the blonde and immediately start drooling. Nash, being a genius economist, is more turned on by the economics of the situation. According to the theory which has formed the basis of modern economics, Adam Smith's Invisible Hand, the best strategy would be for each of Nash's friends to act according to their own preferences. Nash saw this "bottom up" strategy as a problem because, given that his friends all had the same exact preferences, it would be a zero sum game. They would all go for their first choice, the blonde, but only one could possibly succeed (well...). The rest would strike out with her friends who would be insulted that they were all second choices. For Nash, a better (yielding a larger total benefit) strategy would be a coordinated approach. So he devised a "top down" strategy/theory which supposedly debunked Smith's theory.
What do you think? Is Nash's mind that beautiful? Is it safe to assume that preferences are so homogeneous? Personally, when I was in the infantry, I spent plenty of time in bars with buddies...and instances where two or more friends went for the same girl at the same time were definitely the exception rather than the rule. Just like going to Andy's Orchids or SBOE with plant friends. It's never once happened where any two of us have walked away with exactly the same selection of orchids.
Personally, I think Buchanan's mind was far more beautiful...
Individuals differ, one from another, in important and meaningful respects. They differ in physical strength, in courage, in imagination, in artistic skills and appreciation, in basic intelligence, in preferences, in attitudes toward others, in personal life-styles, in ability to deal socially with others, in Weltanschauung, in power to control others, and in command over nonhuman resources. No one can deny the elementary validity of this statement, which is of course amply supported by empirical evidence. We live in a society of individuals, not a society of equals. We can make little or no progress in analyzing the former as if it were the latter. - James M. Buchanan, The Limits of LibertyDifference is the driving force of progress. This means that reducing difference hinders progress. Top down approaches generalize/assume our preferences so they end up reducing differences. Therefore, top down approaches hinder progress.
John Stuart Mill, the father of liberalism, also had a beautiful mind...
As well might it be said, that of two trees, sprung from the same stock one cannot be taller than another but from greater vigor in the original seedling. Is nothing to be attributed to soil, nothing to climate, nothing to difference of exposure - has no storm swept over the one and not the other, no lightning scathed it, no beast browsed on it, no insects preyed on it, no passing stranger stripped off its leaves or its bark? If the trees grew near together, may not the one which, by whatever accident, grew up first, have retarded the other's development by its shade? Human beings are subject to an infinitely greater variety of accidents and external influences than trees, and have infinitely more operation in impairing the growth of one another; since those who begin by being strongest, have almost always hitherto used their strength to keep the others weak. - J.S. Mill, The Negro QuestionKids are at the mercy of the stork just like orchid seeds are at the mercy of the wind. And as Mill pointed out, no two microhabitats are equally conducive to growth.
Many...or most...modern liberals want everybody to have a fair chance to realize their potential. Where it gets really perverse is that they champion a top down approach, which weeds out difference, in order to try and cultivate difference. It's the epitome of counterproductivity. The fact of the matter is that we need difference in order to make progress in cultivating difference. Which is why I support pragmatarianism and have no problem defending herclivation as a theory.
Lindenii, funalis and lindenii x funalis would all be different. If they were all hanging out at a bar together, chances are really good that they wouldn't all go for the blonde. Even if their seeds could somehow coax flying pixies to whisk them away to their preferred ecological niche, chances are really good that they wouldn't all choose the same exact spot. And it's that wonderful difference which would increase their chances of adaptive radiation.
The vast majority of cases where humans have meddled with species, it has turned out bad, often for unforeseen reasons. Why the ghost orchid hybrids should be different is unclear. - tropterrariumAgain, the ghost orchid hybrids would be different because of epiphytic maths...
The epiphytic habit allows for evolution of new types filling previously uninhabited niches in forest trees. Such habitats, being uninhabited, eliminate the serious problem of competition for space suffered by terrestrial plants in the tropics. The development of storage organs in the stems (pseudobulbs) has made expansion into drier epiphytic habitats possible. The presence of the spongy velamen surrounding the roots makes possible the uptake of the maximum amount of water in the shortest period of time. - Calaway H. Dodson, Robert J. Gillespie, The Botany of OrchidsIf anybody can teach epiphytic maths it's the premier epiphyte expert...David Benzing. Here are some relevant passages from his wonderful book...Vascular Epiphytes...
Aggregations comprised of organisms as disparate as barnacles, coral reef fish, and moist tropical forest trees where epiphyte loads may help promote gaps (Strong 1977) all maintain associations in part through lottery-like rotations that prevent competitive exclusion. Dense packing is possible because none of the resident populations is sufficiently mobile or fecund to prevent coexistence. Communities persist because vacant sites (regenerative niches) are usually filled by the first propagule to arrive, an event that does not favor one parent species over another.
Overgrowth of one plant by another is exceptional; instability seems to be too great and living space too fragmented to allow even the most aggressive epiphyte to match the expansion over large areas achieved by many a terrestrial via seeds or ramets. Thus epiphyte synusiae are, perhaps more than some others, shaped by disturbance and patchiness rather than by competition.
The disproportionate proliferation of epiphytes compared to plants of several other habits makes yet another case for the promotive effects of tree crowns as sites for cladogenesis.
Within a forest, total bark surface greatly exceeds that of ground area and can be more densely packed with plants. Rooting media in canopies are also diverse, although whether more or less so than soil is unclear. In effect, tree crowns may be especially permissive habitats that foster dense species packing for vascular and nonvascular plants alike.
Very likely, much of the epiphyte synusia is not yet saturated with either biomass or taxa, even in tropical America; perhaps insufficient stock limits colonization everywhere, but especially in the paleotropics. Too few lineages have evolved adequate stress tolerance for a broader epiphyte presence in seasonal woodlands.Search flickr for "costa rica tree". Now search flickr for "florida tree". Do you see many trees with epiphytic orchids?
Let's switch gears. Epiphytic orchids don't just look pretty...they also provide us with a valuable service...
Epiphytic orchids, on the other hand, although far below the woody plants of a forest, may exceed floor-covering herbaceous plants in total productivity. In many forests and woodlands, then, orchids become quantitatively important in carbon fixation, oxygen-carbon dioxide balance, and mineral recycling. - William W. Sanford, The Ecology of OrchidsIf we zoom out a bit...
Green biomass (and presumably photosynthetic capacity as well) of nonvascular and higher plants anchored in tree crowns can rival - probably even exceed - that of phorophytes. - David Benzing, Vascular EpiphytesUnless I'm interpreting this incorrectly, which is entirely possible, it would seem that epiphytes can be instrumental in the fight against global warming. More orchids on trees means less global warming.
If you grasp epiphytic maths...and grasp the carbon sequestration potential of epiphytes...and grasp that tropical forests are being destroyed at a rapid rate...then perhaps you can grasp the theoretical value of herclivation.
Try and tightly grasp all of that when you consider this illustration...
The tree on the right was mooched from a wonderful paper that I read long ago... Crassulacean Acid Metabolism in Australian Vascular Epiphytes and Some Related Species. Unfortunately, I couldn't find an ungated version of it. A few years back I referenced the paper in this thread on CAM Orchids. If you're interested, you can see the original drawing with a listing of the species over at the New Zealand Epiphyte Network Blog... Aussie Epiphytes. The entry also has some great photos.
I marveled at the original illustration when I saw it for the first time. It does an excellent job of conveying how epiphytes have adapted to different microhabitats. So the illustration quickly came to mind when I first started to think about herclivation.
With some photoshop magic I placed half of the epiphytes onto another tree. Talk about tedium galore. I think it was worth it though.
Looking at the illustration, we can imagine two fictional countries that have perfectly complementary species of epiphytes. Introducing all of Country A's epiphytes to Country B and vice versa (bilateral epiphyte introduction) would double each country's epiphyte biodiversity and greatly increase carbon sequestration. If all other things were equal (ceteris paribus)...which of course they are not...then this would be a great idea.
And again, to be clear, I'm not advocating or suggesting that anybody actually act on this idea. I'm very familiar with the concept of unintended consequences. But when it comes to something as important as biodiversity, then I really don't think we should leave any stone unturned.
Based on my grasp of epiphytic maths, carbon sequestration and the rate of habitat destruction...this idea, or some form of it, has enough merit to warrant serious consideration. So let's imagine that we somehow implemented this idea with Florida and Costa Rica. What would happen? First let's take a look at some basic stats...
65,755 sq mi
100 species of orchids
19,653 sq mi
1446 species of orchids (source)
Costa Rica is less than a 1/3 the size of Florida...but it has 15 times more species of orchids. If aliens visited our planet and demanded that we give them either Florida or Costa Rica then, purely on the basis of orchid diversity, it wouldn't be a very difficult choice. We'd say, "Take Florida". Kinda like the movie Cocoon. But I'm sure somebody would shout..."Nooooo...take California!!"
If Florida and Costa Rica shared all their orchids with each other then Florida would really get the better end of that deal. Or would it? How many Costa Rican species would survive their first winter in Florida? Let's say 400 species. And out of those 400 species...how many would actually be pollinated? Let's say 50 species. And out of those 50 species...how many of their seeds would land on a suitable fungal partner? Let's say 10 species. I guess Florida should have read the fine print. But it would still represent a decent bump in Florida's orchid diversity.
Now let's say that Florida decided to exchange epiphytic orchids with every country in the world. Florida would receive around 20,000 species. Using the same process of elimination as above...what would that turn out to be? Uhhh...I'm not so good at maths maths...
10/1446 = x/20,000
x = 138 epiphytic orchids
It seems kinda low. I wonder what the actual number would be. I also wonder how many species of non-native epiphytic orchids are currently growing on garden trees in Florida right now.
While this is all purely theoretical and hypothetical...I do get the sense that whenever habitat is lost...we need the remaining habitat to support more life. In other words, it seems like there's some sort of natural obligation for the surviving habitat to pick up the slack. In this sense, Florida's "purity", as a standard, seems to be a luxury that we really can't afford. Based on my grasp of epiphytic maths, I don't think it's unreasonable to perceive that, at least in terms of epiphytic orchids, Florida could support far more life without having to sacrifice very much, if any, of its own life. A net gain of biodiversity could very well be the rule, rather than the exception.
I wish I could think of a good analogy. Uh...let's say that the Titanic had assigned seating for their lifeboats. Imagine that, as the Titanic's sinking, there's a large lifeboat with only one person in it. There's dozens of people around the boat drowning and asking to be let on the boat. The person on the boat is saying, "What was your name again? Nope, so sorry, your name isn't on the list. Try that boat over there".
Life is precious, it's quickly being lost, and given that epiphytes, most of which are orchids, represent more than 10% of all plant life, I think herclivation might be able to help save lives. Not only could it help save lives...but, via adaptive radiation, it could help create more lives. And based on the fact that we've all been complicit in the taking of lives...I think we owe the planet and the future a serious discussion on the merits of the various ways that we might help to increase biodiversity.
Our current effect on biodiversity is rather strong, mainly due to habitat reduction. You want to preserve species, preserve land. - tropterrariumPeople say this, but then they also say, "This is fascinating, but not fascinating enough for me to do anything about it".
According to your latest post, which is only your second post in the thread, you're already done with the topic and you won't be posting any more. Well, I wish I had known that the window of opportunity to reply was so small. But hopefully others will be able to evaluate and build on the info that I've shared here.
Regarding the preservation of land...all of us orchid hobbyists would "like" it to be preserved. But we're dealing with a classic free-rider problem. The solution to the free-rider problem is compulsory contributions (taxes) to help pay for public goods (ie conservation). I'm fine with compulsory taxation, my issue is with John Nash channeling Paul Samuelson and thinking he can accurately predict my preferences for women, orchids, conservation or anything else. In other words, I'm not fine with having to try and elect an impersonal shopper (congressperson) to decide how much conservation goes into my shopping cart. I want to decide for myself which public goods go into my shopping cart (pragmatarianism). More importantly, when it comes to public goods, I really want to benefit from the incredible diversity of human perspectives/preferences.
For a more extended treatment of the topic see...The Ingenious Gentleman George Monbiot
But even if we can preserve land...it might be a case of too little too late for the Ghost Orchid...
Regarding the changes in microclimatic conditions, disturbances frequently result in higher solar radiation, temperature and wind velocity, as well as lower humidity compared to the original conditions. The latter may result, again, in a gradual replacement of the mesic species by more xerophytic ones (Cascante-Marin et al. 2006; Padmawathe et al. 2004; Werner & Gradstein 2008; Wolf 2005). - Mondragon et al, Population Ecology of Epiphytic Angiosperms: A ReviewLet me refresh your memory as to what you said in your first post..."More specialized taxa have a greater probability (or Popperian propensity, if you wish) for extinction (plenty of evidence in fossil record)." Just like I wasn't able to predict that you would be done with the topic so quickly...I don't think we can accurately predict where the climate tipping point is for the Ghost Orchid's survival in nature. And when it comes to difficult predictions, the best strategy is to hedge our bets.
Anyways, this blog entry / reply is sort of a hodgepodge garden. Maybe gnathaniel can make some sense out of this mess. But at the bare minimum, herclivation represents some out-of-the-box thinking. And I'm pretty sure that out-of-the-box thinking is something that epiphytes would certainly appreciate. In fact, we should call it epiphytic thinking.
I'll leave you with this neat-o video...
Woah, what are you still doing here? This blog entry ended a long time ago. Are you looking for an Easter Egg? Ok. Your Easter Egg is the following assignment. Please predict what would happen to biodiversity if hummingbirds were introduced to the rest of the world.