Every now and then it occurs to me that I should document some of the hypotheses in my mind that might make interesting research questions at some indefinite point in the future. Here’s one:

If the historical reference community for a given site was a patchy grassland, with alternating dense perennial grass patches and sparsely vegetated patches (usually these are more or less linear or arcuate and perpendicular to the slope), grazing that is at a level that reduces perennial grass cover while still leaving perennial grasses dominant will also increase the size of both the grass patches and the sparsely vegetated patches (the latter, presumably, increasing more).

And another hypothesis, closely related to the above:

In an area with two ecological sites / topographic units, both having perennial grassland as the historical reference community but one typified by much denser grassland than the other (an example would be a draw surrounded by loamy plains), reductions in perennial grass cover caused by grazing will be greatest immediately adjacent to the more densely vegetated ecological site. This causes a long-term pattern in which what would have been a more or less bell-curve-shaped distribution of grass density in a cross section of the draw and its surroundings into a trimodal distribution, with a tall central peak and two small but broad peaks at some distance (presumably set by factors like terrain complexity, climate / water availability, forage availability relative to stocking rate, and so forth) from the draw. The tall central peak would be the next to diminish and eventually disappear. At one extreme, in a broad valley surrounded by low rocky hills, this can create a situation in which grass cover is inversely proportional to soil moisture; grasses remain on the rocky slopes where runoff is high and water-holding capacity relatively low while being eliminated from the more finely textured soils and shallower slopes near the valley bottom, and from the valley bottom itself.

As a result of this, utilization of grasses by livestock may be inversely proportional to grass cover, even in sites relatively near water with limited overall forage availability, if slopes adjacent to a drainage are steep or merely rocky. At the extreme of that phenomenon, you may have slight or no utilization of perennial grasses under heavy grazing pressure. This is the landform equivalent of seeing perennial grasses only within shrubs and can produce a map of forage availability and forage utilization that, read naively, would indicate minimal grazing pressure and relatively abundant forage.

In reading articles about current protests by Black Lives Matter and allied groups against police violence, triggered by the murder of George Floyd, I’ve noticed a particular rhetorical move that seems incredibly bizarre and counterproductive to me. My intent in writing this is not to discuss the relative merits of different political or moral positions regarding these protests (short version: I am sympathetic to the protestors). Instead, I feel I need to write down what’s rhetorically odd to me, here, but don’t want to do so in a forum where doing so would be likely to devolve into unproductive discussion in which a narrow disagreement with a particular rhetorical approach may be misinterpreted as a broader support for police violence or racism. In any case, here’s the article that prompts my interest at the moment, in the following text: “Would it not be better, Democratic strategist Greg Pinelo wondered, to talk about ‘police reform’ rather than abolition, given that the former polls at 80 percent approval and the latter at just 10? (‘It’s called branding,’ he smugly counseled, as though a call for justice were nothing more than a product launch.)”

Marketers care if something works and nothing else. It is entirely understandable that one wouldn’t want to be morally associated with them. However, suppose we have a social cause that is important to us and we want desperately for our efforts to be successful. Does this make it more, or less, important to use methods that work? It’s like saying that it is of vital importance that your car get you to Reno–therefore you’ll ignore the “check engine” light. Marketers take their cars to mechanics. I don’t think people are very good at switching between moral reasoning and pragmatism. Once we have a compelling moral cause and our minds are focused on the moral analysis of the situation, appeals to pragmatism become crass. You’re motivated by a feeling of righteousness, and there is nothing less righteous than logistics. Switching to pragmatic concerns requires, at least temporarily, letting go of that feeling. It feels like abandoning the moral high ground. Even if not immoral, as the association with marketers suggests, pragmatic concerns are always amoral. How well a car functions has nothing to do with the moral position of the driver. If it’s broken, you will not fix it by moral reasoning; you have to let go of any concern about morality and worry about mechanical and electronic matters. You have to abandon your morality, or at least put it out of your mind. Here’s the thing—that change in your mind, of itself, has absolutely no effect on anything outside of your conscious experience. The cause against police brutality is not lost because you aren’t thinking about morality for a while. You just don’t have that wonderfully addictive feeling of moral superiority in those moments. Do you value that emotional experience more than people’s lives?

I’ve noticed that a couple of oddities with regard to sandy / sandy loam soils. In the Las Cruces District, sometimes a sandy loam will have a flora that is more indicative of loamy or clayey sites. These are also generally not “fluffy” soils, but relatively compact. Further north, recently in Socorro County but especially prominent on the Colorado Plateau, there are very “fluffy” soils that often have psammophilic plants on them. I think these soils will generally come out as sandy loams, but I have not often textured them or learned the texture from others. If they are sandy loams, and have psammophilic plants on them, that may not be a mystery, but the “fluffiness” is. In apparent surface texture as one walks through these areas, they have nothing to do with the sandy soils to the south. I wonder if sand size is an important factor here; the finer sands border on silt, so perhaps act like silt in terms of walking-apparent soil texture but like sands as far as many of the plants are concerned. Particularly coarse sands, perhaps, could explain the sandy loams without psammophiles. Or perhaps there is a clay percentage above which the soil will still fall into the sandy loam category, but cease to act much like one as far as plants are concerned. Parent material likely plays some role here, as the “fluffy” soils are in predominately sedimentary areas and the troubling sandy loams in southern New Mexico are in predominately igneous areas.

The taxonomy of fish is often taken to be important and symbolic: how our intuitive taxonomic concepts are wrong, or why they should trump scientific results, or something about hubris, or how concepts construct reality. This all relies on the idea that modern phylogenetic methods have told us something deeply surprising, or even mysterious. We all think we know what fish are but, aha! fish are not even a real category. This means, for modern taxonomists, that they are not a clade. Some fish are more closely related to land animals than to other fish.

However, I think the results of modern phylogenetics aren’t surprising, if you know a little about fish. When most of us think of fish, we’re really just thinking of ray-finned fishes, Actinoptergyii, and Actinopterygii is a clade. It is a perfectly good taxon, intuitively and phylogenetically. The other “fish” are hagfish, lampreys, sharks & rays, and lobe-finned fish. If you have a mental image of a hagfish, compare that to your mental image of “fish”; if not, resort to google. Is it very surprising that hagfish are something different? Try the same for lampreys. Sharks and rays are well-known and also, I think, an intuitively obvious taxon. If you just looked out at the world of fish and started mentally grouping them together, I think you would pull these three groups out very quickly and naturally. Or maybe you would group hagfish and lampreys together, but still be certain that they aren’t in the same group as trout, sardines, and the like. The lobe-finned fish might not be as obvious. Coelacanths are famous for being weird, but if you saw a coelacanth or a lungfish it might fit well enough with your mental image of “fish”. If you start learning a little more about them, though, some obvious oddities pop up pretty quickly. Lungfish have, for instance, lungs. So it might be surprising for these to be a different group from our familiar ray-finned fishes, but not very surprising with a little knowledge.

The main surprise might be that lobe-finned fish are so closely related to land animals. And maybe you would have assumed that these five groups of fish all share a common ancestor–but I don’t really think phylogeny plays an explicit role in intuitive taxonomy except after long training. Your mental image of fish isn’t a phylogeny, it’s a mental map of similarities and differences between animals. And if that mental map is at all well-developed, it would already have most or all of the five clades within fish as well-developed, separate categories. The phylogenetic results are as much a confirmation of intuitive taxonomy as a rejection of it. You can phrase it to sound surprising–fish aren’t real!–or you can phrase it to sound unsurprising–did you know sharks are in a separate group from catfish? Framing it as a surprise makes for a more exciting story, of course, but it also draws a big line between what we think we know about the world and what people in labcoats tell us about the world. I think this is unhelpful, and anti-scientific even if not presented with that intent. Science is about understanding, but this framing tells us that there’s a gap between science and what we understand.

Viewed from one side, there is no representation of a thing short of the thing itself. Viewed from another side, the representation is identical to the thing itself.

After the 2016 election, there was a narrative in which we liberal elitists blamed ourselves for not connecting with rural voters. It’s still around, and I don’t like it. It feels like a puzzle that has most of the right pieces, and they look like they fit together from one side, but are a jumbled mess seen from the other. I have a story.

Remember when you complained in 6th grade about being stuck on a group assignment with a dolt? The teacher told you, although not this directly, that as a more enlightened being it was your duty to help bring the less fortunate up to your level. You thought this was some buck-passing bullshit, and you were right. How could you be responsible for the betterment of someone who resented you, and from whose culture you were alienated? The problem wasn’t really that he was a dolt, though he was, but that this role required a social rapport that wasn’t there and social skills you didn’t have. Being tossed in the deep end didn’t cause these qualities to appear, but made their absence more painfully obvious.

I don’t remember choosing this divide and I don’t know how to unchoose it now.

When I write down where I’ve been, I’m left with descriptions like this: “South-southeast of Deming and west of the Florida Mountains, northwest of South Peak.” It’s not a place, it’s a gap between places. When you look at a map, most of the place is a gap.

In 2013 I was the first author on a paper on the phylogeny of Boechera, which included splitting the genus into three: Boechera s.s., Borodinia, and Yosemitea. Since then, Mike Windham, a coauthor on that paper, has used microsatellite data to learn much more about intergeneric hybrids involving Boechera s.s. At the time the 2013 paper was written, we thought there was one (Boechera tiehmii), but didn’t have much clarity on what was going on in that case. Mike sorted out the origin of Boechera tiehmii (which I suppose must receive either a hybrid formula or nothogenus at this point) and uncovered several more hybrids and their origins. Noteworthy for the split of Boechera s.l., some of these hybrids are between members of Boechera and Borodinia. Mike gave a presentation at Botany 2014 on these hybrids, and he has interpreted these hybrids as making the separation of Boechera and Borodinia untenable. This counterargument is not explicit in the publicly-accessible abstract of the presentation, which I provide below in case the link disappears, but has been floating around in “pers. comm.” land as a nomenclatural asterisk, a suggestion that this separation has been rejected by further research without a clear explanation of the reasoning involved. Since I disagree with Mike on the nomenclatural question here, I thought it might be worthwhile to write and publish here my best attempt to explain the situation. I should first make it clear that my disagreement with Mike is quite narrow. I think Mike is almost always right on taxonomic questions, and even in this case I have no doubt regarding the hybrid lineages he has uncovered and disagree only on their nomenclatural implications.

The Botany 2014 abstract:

Newly documented hybrids in the tribe Boechereae (Brassicaceae) challenge current generic circumscriptions in the group.

As circumscribed by Al-Shehbaz in 2012, the largely North American mustard tribe Boechereae included 126 accepted species divided among eight genera: Anelsonia (1), Boechera (110), Borodinia (1), Cusickiella (2), Nevada (1), Phoenicaulis (1), Polyctenium (1), and Sandbergia (1). A subsequent publication by Alexander et al. in 2013 transferred seven species from Boechera to Borodinia and added the monospecific genus Yosemitea, also segregated from Boechera, based on a combination of molecular and morphological evidence. Boechera, by far the most diverse genus in the tribe, is notorious for harboring a network of interspecific hybrids constrained only by geographic isolation or deep phylogenetic divergence. Now, microsatellite-based studies of Boechera and related genera reveal the existence of three previously undocumented hybrids that challenge the efficacy of even phylogenetic distance in preventing hybridization within Boechereae. One of the new hybrids is an apomictic triploid combining genomes from two core Boechera species (B. arcuata and B. perennans) with a genome from B. davidsonii, a distinctive species robustly resolved as sister to all other Boechera s.s.. The species currently called B. tiehmii is shown to have arisen through hybridization between B. lemmonii and the monospecific genus Nevada. Finally, all eastern North American populations previously assigned to B. stricta prove to be allotetraploid hybrids between that species and Borodinia laevigata. Whereas the Boechera/Nevada hybrids do not appear to backcross with either parental lineage and could be assigned to a new nothogenus, this is not true for tetraploid Boechera stricta × Borodinia laevigata. This taxon hybridizes with several species of Boechera s.s., in addition to forming rare triploid backcrosses with B. laevigata.

Since gene flow between Boechera and Borodinia is one of the obvious arguments for merging the two genera, I think it’s worth mentioning that hybrids between Boechera stricta × Borodinia laevigata and Boechera s.s. or Borodinia do not imply gene flow between the two genera. The usual scenario in Boechera is that a digenomic hybrid is diploid and apomictic, and can produce triploid, di- or trigenomic hybrids through diploid sperm from unreduced spores in the digenomic hybrid uniting with a haploid egg from normal meiosis in a sexual diploid species. Basically, hybridization is rampant and complex but doesn’t result in gene flow back into the parents. The scenario described in the abstract for Boechera × Borodinia hybrids is an allotetraploid, digenomic hybrid that can backcross with sexual diploid Borodinia and with Boechera s.s. The backcrosses to Borodinia produce triploid hybrids, implying diploid gametes produced through normal meiosis in the allotetraploid uniting with haploid gametes through normal meiosis in Borodinia. I don’t know the details of the backcrosses to Boechera s.s., but in the research I’m aware of there is no known mechanism for gene flow to get from an allopolyploid back into sexual diploid Boechera. This leaves a couple of different ways of producing allopolyploid apomicts in play. The general Boechera rule that backcrossing creates new, reproductively independent lineages rather than gene flow between existing lineages is still in effect here, so far as I know.

Mike’s interpretation, based on a couple of emails he sent on the topic, is that the hybridization scenario here makes it impossible to recognize Borodinia as a segregate genus based on a particular interpretation of the nomenclatural possibilities. He believes that a Borodinia × Boechera hybrid could be assigned to a nothogenus but a (Boechera × Borodinia) × Boechera or (Boechera × Borodinia) × Borodinia hybrid could not. If we can’t assign such hybrids to a nothogenus and we must assign all plants to a genus, it follows that we cannot maintain Boechera and Borodinia as separate genera.

If Mike is correct, we would have to combine these two genera but it is not clear what circumscription of Boechera would result. Simply combining Boechera and Borodinia is viable if we’re willing to accept a genus that may or may not be monophyletic, but not viable if we restrict ourselves to genera that existing phylogenetic analyses support as monophyletic. If we restrict ourselves to monophyly, Boechereae as a whole becomes a single genus (for which the name Phoenicaulis would have priority). A third possibility here is that we prioritize stability over monophyly and retain the nomenclature in place prior to Alexander et al. (2013) until we can be certain that two conditions hold: Boechera s.l. (i.e., as treated in the Flora of North America and in the series of papers by Al-Shehbaz or Windham & Al-Shehbaz leading up to the Flora of North America treatment) is not monophyletic, and a monophyletic Boechera smaller than Boechereae can be identified.

I do not agree with Mike on either of the two nomenclatural points necessary for his argument, that the backcrosses cannot belong to a nothogenus used for hybrids between Borodinia and Boechera, or that all plants must be assigned to a genus. The first point is covered by ICNafp article H.4: “a nothotaxon is circumscribed so as to include all individuals recognizably derived from the crossing of representatives of the stated parent taxa (i.e. not only the F1 but subsequent filial generations and also back-crosses and combinations of these)”. A possible objection in the case Boechera and Borodinia is that there are different parental taxa at the species rank. For instance, a hybrid between Boechera stricta and Borodinia laevigata would not have the same parents as a hybrid between Boechera stricta × Borodinia laevigata and Boechera collinsii (this latter is only an example; I do not know if such a lineage is known). Article H.6, covering the names of hybrid genera, removes this possible objection. Parental genera, not parental species, play a role in the names of hybrid species; e.g., ×Agropogon is Agrostis × Polypogon. At the generic rank, (Boechera stricta × Borodinia laevigata) × Boechera collinsii is simply Boechera × Borodinia. The second point is covered by article H.2, “A hybrid between named taxa may be indicated by placing the multiplication sign × between the names of the taxa; the whole expression is then called a hybrid formula,” and article H.3.1, “Hybrids between representatives of two or more taxa may receive a name.” There is no obligation to create a name for any particular hybrid. We can name a nothogenus for Boechera × Borodinia if we like, or refrain from doing so and use the hybrid formula. If we did name such a nothogenus, it would include all hybrids between Boechera and Borodinia.

I still think the split of Boechera s.l. into Boechera s.s., Borodinia, and Yosemitea is the best solution to this nomenclatural puzzle. I don’t think it is unequivocally correct or that there isn’t room for reasonable disagreement, but in my mind the uncertainty revolves around the poor resolution at basal nodes in Boechereae. I stand by the reasoning I was following in the 2013 paper–if we want to have monophyletic genera and our best guess (without good resolution to nail things down!) is that Boechera s.l. is not monophyletic, recognizing these three segregates gives us a generic nomenclature that is unlikely to become untenable if we get better resolution and sort out those uncertain nodes. The split might well become unnecessary once those nodes are resolved, but it would still be a viable option, and at present is the option that is most likely to be stable across different possible resolutions of these nodes. The hybridization Mike uncovered between Boechera and Borodinia certainly adds more nuance and complexity to an already complicated situation and furthers our understanding of Boechereae, but I don’t think it forces our hand in nomenclature and it doesn’t change my understanding of the phylogenetic situation.

Cicadas whine
as the ground shimmers,
then darkens
and flaps.

Walking west,
I feel seen.
Looking east,
Yucca is seen.