Taxonomy is the bedrock of communication about life. If other facets of communication changed, it'd be pretty frustrating, e.g., "from here on, hello will mean mustard". I witnessed the saltiness of taxonomic change first hand in South Africa. Africans had spent their lives calling their iconic, thorny trees Acacia. Acacia even means thorny. That didn't suit taxonomists and all the African acacia were renamed to Vachellia. The non-thorny Aussie trees, of which there were >1,000 species compared to 100-ish in Africa, took the name. Ja, I can see why they'd be salty. In other areas of science, we support or reject hypotheses and move on. Taxonomy is descriptive, hypotheses can be loosely applied (we hypothesise this is a monophyletic group of taxa), but it's a stretch. When two people describe the same piece of art or music, they may differ in their opinion. The same is true for taxonomy. Applying taxonomic ranks to organisms is arbitrary and cases can be made to split or lump any rank at a shared common ancestor. Ultimately, determining gene flow among populations paints a clear picture of species boundaries, but who has the time to do this for millions of fungi. I find it interesting that we become attached to taxonomic names, even when there is evidence to support that they should be called something else. I think we are more emotional because of the vagueness in species/taxon delimitation. In the smut and rust section of this blog, you can read about the taxonomic name for corn smut and why it should be called something other than Ustilago (but jeeze, you'd have to be bored). Clearly even I become emotional about taxonomy. Taxonomic names, as long as they were validly described, are always there for communication and can be used eternally (as long as people know what organism you mean). Just 'cause some fella is saying all the northern hemisphere wood-loving shrooms are Psilocybe subaeruginosa doesn't mean you have to forgo these names. Keep on using them... what do you think African people call acacia (hint: not Vachellia)? The only change here is that we know Australia is the centre of origin of P. subaeruginosa and it has spread to the northern hemisphere where multiple new names have been applied to one taxon. Population diversity illustrated for two species of Psilocybe and several species of Colletotrichum. A. SplitsTree neighbor network based on 382 single copy orthologs identified by OrthoFinder between P. cubensis and P. subaeruginosa. Edge length reflects genetic difference and reticulation is an indication of recombination. B. Network of relatedness among genomes (large circles) and clusters of accessory orthogroups (small grey circles), with nodes and edges coloured by species of Psilocybe. C. SplitsTree neighbor network based on 3,144 single copy orthologs in the Colletotrichum gloeosporioides species complex. The scale is a magnitude smaller than between species of Psilocybe. Long edges radiating from reticulation is a signature of clonal reproduction. A test for the pairwise homoplasy index was 0.0, which indicates randomness of alleles across the alignment and is evidence of reproduction. D. Network of relatedness among genomes (large circles) and 7,989 clusters of accessory orthogroups (small grey circles), with nodes and edges coloured by species of Colletotrichum. Species cluster together to some extent based on their shared accessory genes, however, there is no strong separation of genomes and accessory orthogroups are shared among taxa. The figure illustrates genomic relationships based on core and accessory genes between sister species. For magic mushrooms, the sisters are cubes and subs. Note they are highly separated by core genes and there is almost no overlap of accessory (non-core) genes. Colletotrichum is the other example, and it has been split like a banana in a dessert bar. Note that the core and accessory don't clearly separate species. Likely these are all the same taxon and taxonomists have described clones as different species (which could be acceptable in some instances).
After this explanation, if you still prefer species complexes and lots of names for the same taxon, why not spend your time and resources examining the boundaries of recombination to demonstrate speciation in process?
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Set and setting, and psilocin binding to 5HT2A receptors are the two domgas of how magic mushrooms work. To the point it feels that's all we think matters to dictate a psilocybin experience from magic mushrooms. Let's think back a couple of million years to before mammals were on the scene. Under a clock-like rate of speciation, species are between 500K to 5 million years old. Genera are somewhat older, and Basidiomycota are an anomaly compared to other organisms. Genera of Basidiomycota are usually 20–100 million years old. (Check out this paper if you want to read more: https://academic.oup.com/mbe/article/32/4/835/1078218). Psilocybe could be anywhere from 20 to 100 million years old. We assume that the most recent common ancestor of all species of Psilocybe could produce psilocybin (because all except one produce it), and likely psilocybin is the same age as Psilocybe. All species of Psilocybe, extant and extinct, have forged their way in niches of leaf litter, wood, grass, moss, and dung. We don't know the exact purpose of psilocybin, whether to repel, control, or attract, but we can be certain it targets metazoans with serotonin receptors. Whatever metazoans dominate the different niches of Psilocybe, we can be sure over an evolutionary time scale the genes that produce psilocybin in 200 or so species are refined to best target species of slug, arthropod, nematode, or whatever was eating it for whatever reason in whatever niche. This has happened time and again with co-evolved relationships, especially those with metabolites governing the symbiosis. If you accept that there are different predators across 200 species of Psilocybe, you may be on the way to understanding why I think different magic mushrooms give different psychedelic experiences. Different effects from different species given an evolutionary time scale is hopefully palatable, but to say that allelic variation in one species changes an experience is more difficult to swallow, especially with the dogmas of how trips work. We showed that populations of P. subaeruginosa maintain genetic diversity in the alleles that produce psilocybin rather than just one becoming dominant (balancing selection to be fancy). This is probably why WLP can be in some, but not all genotypes and is maintained in populations. What the blazes is the benefit of all this diversity? Diversity to the extent that psilocybin alleles are barely shared by closely related populations and there is reason to suspect recombination within the locus itself that would ensure that the same alleles in the pathway are not linked (or not always inherited together).
Long story short, our work on subs shows an evolutionary process of maintaining allelic diversity in the psilocybin pathway (or balancing selection). Cubes have a solid 5–6 alleles at the psilocybin locus in the entire population of cultivated mushrooms and a bunch more in naturalised populations. I've grown most of these and am in the process of testing the tryptamine landscape in homozygous genotypes. I've crossed different alleles to see what happens when the psilocybin locus is heterozygous. I've never been more convinced that there are phenotypic impacts from genotypic diversity, and I hope to hold hard evidence soon. Rest assured, if the time comes, the people will be able to decide if there are differences themselves. In the meantime, do me a favour next sub season: don't combine harvests from different patches. Experience them separately and share whether there is a difference (given a consistent set and setting). Expect there to be different psilocybin alleles at different mushroom sites, unless the mushrooms are harvested from mulch/woodchips that have been spread artificially (wild harvests will guaranteed be different alleles). More on all this soon. Full piece at Current Biology here:
https://www.sciencedirect.com/science/article/pii/S0960982223014604?dgcid=author. And just in case you hadn't seen that our sub work is publicly available, just not peer reviewed right here: https://www.authorea.com/users/700719/articles/687526-wood-loving-magic-mushrooms-from-australia-are-saprotrophic-invaders-in-the-northern-hemisphere. |
Designer Shrooms @ Funky Fungus on 1st July 2023
I started a gig at Funky Fungus as Chief Scientific Officer to make designer shrooms Our research on Psilocybe
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