I disagree - this is making the assumption that the current number of species is correct, but there is still an enormous fraction of the world’s biodiversity that has not yet been formally described. These are not new species that are coming into existence right now, they are species that have existed for thousands to millions of years and we just did not know about until now. Ignoring them would not help the biodiversity crisis, and undoubtably many of them are critically imperilled species that can only be protected if we know about them. We currently have no idea how many species there are in the world, so that is not a metric that can be used to measure the success at preserving species.
5 Likes
I am not making an assumption that the current number of species is correct.
I am saying that Dandelions in Ohio are effectively one species in terms of “real-world biological meaning”. If Dandelions in Ohio are split into 10 species, it may appear that we are preserving species (in terms of total species count) when in reality we are splitting dandelions with the benefit of whatever new technology is used to describe them.
2 Likes
I was responding to your previous statement that “the rank shouldn’t be allowed to grow faster than the baseline rate of evolution due to advancement in technology”, but if the focus is just on Ohio, then I would make the same argument - we have no idea how many species are in Ohio, nor how many have been extirpated, so we simply cannot use total number of species as a metric to monitor conservation efforts. Whether the dandelions are best thought of as one species or many is not a new question, but it is one that newer technologies can help us address and give us more information to make informed decisions.
5 Likes
In the case of taraxacum, whether description or hybridization is dominant in producing new microspecies is a hypothesis. There are several papers (see e.g., https://natuurtijdschriften.nl/pub/540475) that remark that agricultural areas seem to be populated by dozens of distinct local specialist microspecies that seem to have adaptations specific to industrial agriculture, even when industrial agriculture has only been present at that level for a few decades. One hypothesis could be that those microspecies were already present but subdominant, and another could be that they are just all new ‘species’ formed in those few decades.
I’m not sure whether there is currently much suggestion that they are diverging into distinct species; possibly the opposite. I think the two hypotheses most supportable with current data would be that microspecies are either evolutionary ‘dead ends’ or are individual units of a collective that is still actively mixing. (There is some mutation within the asexual lines that could potentially lead to evolution but I do not think this is regarded by anything I have read as the primary method of evolution in taraxacum).
The microspecies are ‘asexual’ because they are not self-fertile; they are usually completely incapable of fertilizing individuals of the same microspecies. However the European microspecies may hybridize readily with other European microspecies or with native sexual North American and Asian dandelions, even ones that are nominally different macrospecies (e.g., different sections). So in terms of the ecology the concern is possibly less that they are diverging as that the current evolution may be bringing previously distinct evolutionary units together. Or, maybe they weren’t ever really fully distinct evolutionary units in the first place and were just geographically separated for some 10s of millennia.
3 Likes
I’m curious what new technology you see going into dandelion taxonomy. From what research I’ve done these taxa are based on very old technology of morphometrics and visual characters. No one is sequencing for micro species, they are cultivating and vouchering. That’s not to say they are more or less valid, but that this “proliferation” of Taraxacum microspecies (which seems abrupt to Americans who have not been playing attention to the state of taxonomic opinion in Europe) is not a change in how taxonomist identify species or understand species but an application of very established methods of defining and identifying species to a case that strains our definition and methods.
If we are going to actively understand and conserve biodiversity we have to name it. Franky I find arguments over what level a taxa is maintained at wholly uninteresting, but I must make an observation. It seems to me that taxonomic workers are far more comfortable ignoring or erasing subspecies or varieties (infraspecies) than they are doing the same for species. I think the tendency to identify taxa at the species level is partly a response to 20th century workers who dramatically over lumped species AND eliminated taxa. If you want an obviously distinct plant to stay recognized it better be at species or the next person writing a flora may choose to ignore it without a note.
I don’t know how I feel about microspecies yet, but I do know that there is more Taraxacum diversity and uniformity than I was aware of 2 weeks ago. Similar looking plant leaves seem to be showing up in similar spots, and if I were looking to preserve the diversity of these lineages I would need a lot of names to even begin to understand them. I don’t know if it fundamentally matters if a apomictic lineage goes extinct, but it certainly feels to me right now like a reduction in diversity more than something akin to just the loss of an individual.
5 Likes
Correct; loss of an entire apomictic microspecies is equivalent to genetic loss of somewhere between one and two distinct diploid individuals from a regular sexual reproducing species. Note that this complete lack of internal diversity is why no one has argued that the microspecies should be called ‘subspecies’; no individual microspecies has enough diversity to merit elevation to full subspecies status. For that reason the ‘subspecies’ option is equally unpalatable to both sides of the disagreement. It’s just that, in the current formal nomenclature, if they aren’t subspecies, there isn’t necessarily a great option to call them that is in between a full species and nothing.
They are basically at the same taxonomic level as what horticulturalists would call a ‘cultivar’, but that is not an option for a natural hybrid. As I have said I inat’s ‘infrahybrid’ is the closest compromise option; the code of botanical nomenclature has no rules at all about naming those (it barely acknowledges the rank could exist) which is I suspect part of why that rank hasn’t been used for this purpose formally.
This is because sequencing generally does not work well for identifying first-generation hybrids as a species concept. When you have a bunch of hybrids that just have different permutations of the same set of chromosomes, there isn’t any good way to define a set of genetic markers that can distinguish the hybrids from each other. Different seeds from the same fertilization event between two parent plants could be different microspecies. A full genome DNA sequence of the nuclear genome could be identical and they could still be different microspecies if the chloroplast DNA is different. For the same reason, it is also effectively impossible to do any sort of cladistic analysis within a section. You could try looking for random point errors, but that would be difficult and possibly not fruitful; as the FNA says, the variation between microspecies is continuous and multi-dimensional:
The species most familiar to North Americans were introduced from Europe (T. officinale and T. erythrospermum ; see below for a justification of the use of these names), possibly several times, and represent variable agamic complexes, but this variation appears continuous and multidimensional. There seems to be no utility for the users in describing a multitude of narrowly defined microspecies.
Note that the difficulty in effectively classifying the microspecies using DNA is one of the reasons why it is possible to pick an ‘ambiguous’ specimen as the lectotype for T. officinale as I described above in https://forum.inaturalist.org/t/my-dandelion-manifesto/49999/105
1 Like
but all species are ‘made up’ and what is ‘valid’ is also a social construct. I don’t understand why people are so beholden to POWO when POWO is clearly engaging in a taxonomic scheme that’s totally unusable for a photo-based citizen/community science website. I actually think iNat SHOULD do just what you said we shouldn’t ever do. Maybe that’s the minority opinion. But maybe not! It’s not like it’s illegal or violates a law of physics. We the community, or at least the iNat admins, are the ones who ultimately decide what it can and can’t do, within the laws of nation-states and the universe itself.
There are already many different taxonomic schemes out there, i don’t think an iNat one would be inherently worse than others. I don’t think the current hypersplitty academic taxonomy regime is always (or ever?) the best way to go.
Well maybe then ‘taxonomy’ in that form has outlived its usefulness for anything other than genetic sequencers and PhD-holding taxonomists and the rest of us need to move on to what is next.
You realize that is exactly what the splitters are doing though, right? And to species level too…
In terms of ‘exotic locales’ i do believe it’s important to remember iNat is a global site. The Amazon is no more ‘remote’ than Ohio, depending on where you live. It takes a lot of privelege to travel a lot, but if the iNat user lives in Brazil they’d need a lot more money to study T. flexipes than frogs in the Amazon.
2 Likes
Actually, some people have treated these “microspecies” as full species.
2 Likes
This is not strictly correct. Your process makes it research grade as Genus Taraxacum - regardless of whether your ID is disagreeing or non-disagreeing. Research Grade refers to the community ID not the observation taxon. The way this is presented on most pages is thoroughly misleading however - it will look like a RG T. officianale to most people.
2 Likes
As others and myself have said in many threads discussing splitting:
I am neither a splitter or a lumper, because I am not a taxonomist. Species I specialize in have undergone quite a few splits (e.g., Rallus species), and I believe all were warranted (certainly they weren’t at the ecotype level, they were already considered separate subspecies). I understand there is a huge difference between plant and animal taxonomy, but I still think concerns over rampant splitting are largely overblown.
i’m glad you haven’t experienced problems with rampant splitting but i thnk it’s worth listening to others who have had problems with it, and a lot of people have. With the existence of the subspecies rank plus the known problems many have, it’s hard to come up with a good-intention justification for it all at species level.
2 Likes
True, but has anyone said they should be full subspecies? I’m talking about the apomictic ones specifically, the sexual ones could defensibly be full sub-species (or species) if they wanted to be.
When you’re suggesting that iNaturalist follow its own taxonomic ideas, realize that in order for the names we use to be taken seriously, if they’re names at one of the formal ranks we recognize in taxonomy, it’s necessary to define and describe those taxa carefully, including selecting a type specimen. These rules are designed to reduce the confusion over names. If you screw up (as even those of us with the best of intentions sometimes do) or ignore the rules, you create more chaos. Formally naming taxa isn’t all that hard, but it does take some thought.
It seems the comments here sometimes conflate to issues. One is plant taxonomy in general – are species useful ranks? what is useful to name? Actually, plant taxonomy works, for most taxa in most places. It ain’t broke, so lets not assume we need to abandon it. The other issue is dandelion taxonomy and how to solve it. Dandelion taxonomy, classification, evolution, breeding systems are seriously messy for good biological reasons. We can discuss this until the cows come home and won’t solve it, though the argument can be fun. I think we shouldn’t generalize beyond dandelions too much, though.
5 Likes
A lot of people take issue with it, but I don’t know that a lot of problems have been caused by it. Again, I am neither a lumper or a splitter. I think the biggest difference between the two of us is I am willing to take a “it depends on the situation” approach where I believe you have a more “zero tollerance” approach, proposing to keep taxonomy static with limited revisions every 30 years (apologies, if I am misattributing this to you or misremembering the specifics). If so, you also need to be aware that this would also be problematic for a large number of people. But alas, the splitter vs. lumper drama is both uninteresting to me and off-topic for this thread.
1 Like
but if it ain’t broke, why is it being completely splattered to bits by excessive splitting and renaming? it didn’t seem broken before they did that, so why ‘fix’ it that way?
I’d be willing to take an ‘it depends’ approach if there was actually balance and it wasn’t just controlled by the splitting contingent. People ask what I think we should do, so i tell them. I don’t actually expect my ‘extreme’ view to be accepted, but what i’d hope people to recognize would be that the other extreme is really disruptive as well.
I think ‘splitter vs lumper drama’ is very much exemplified by trying to elevate these minute taraxacum variations as full species. Like Taraxacum microspecies to species level are one of the most heinous examples of splitting out there. So it’s not off topic at all. And instead of the lock-step POWO thing maybe people should actually describe why having the microspecies at species rather than subspecies level is actually a good idea? Because all i ever hear is ‘we have to do it because POWO’
1 Like
We’re talking at multiple different levels here…
- What we can do as iNat curators with iNat’s taxonomy within the constraints of iNat’s guidelines as created by the staff.
- How we could do things differently if iNat’s taxonomy rules were changed, but still constrained by formal external taxonomy.
- How we could do things differently if formal external taxonomy was different.
Levels 2 and 3 are fun to theorize about but we have essentially no control over them in this conversation. For practical purposes level 1 is the only one that participants in this conversation have significant influence over, but that influence is limited by the constraints mentioned.
3 Likes
Some of the earlier points in this discussion, I didn’t follow the train of thought at all.
-
“They don’t have enough variation to qualify as subspecies, so we’ll make them species”? But don’t species usually have more variation, which is why subspecies can exist within species?
-
Referring to them as equivalent to cultivars, and in the same sentence bringing up the problems of sequencing first-generation hybrids? But many cultivars are not first-generation hybrids, as the current popularity of heirloom varieties attests.
Perhaps landraces would be a suitable term – a landrace is a cultivar (or animal breed) which has been selected for adaptation to a particular locality, genetically distinct from its conspecifics in other localities, but still the same species.
1 Like
well the guidelines say to use POWO but do allow deviations. While in the longer term we could build data to request rejection of POWO, in the short term we can start deviating more from these splits within the constraints of the guidelines if we can get enough people to support doing so. But that is difficult because mostly only taxonomic splitters are allowed to make taxonomic changes on here (or elsewhere)
1 Like
My statement in this context has nothing to do with POWO. Instead it concerns the fact that we would be inventing scientific names here on iNaturalist - ones that have never been published. If that is the door you really want to open, then we may as well make everyone a Curator, and let everyone make up the scientific names that please their sense of a just taxonomy.
4 Likes
I phrased it that way because I also think it is kind of a weird. My statement should be read as reflecting my best understanding of the reason taxonomists don’t want to call them subspecies, not my agreement with the sentiment.
I don’t see a disagreement? Certainly not all cultivars are F1 hybrids, but a subset are; e.g., agricultural F1 hybrids are often called cultivars:
In agronomy, the term F1 hybrid is usually reserved for agricultural cultivars derived from two-parent cultivars.
1 Like