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contingo

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contingo
·3 tahun yang lalu·discuss
But it's not a "hitherto conjectured form of symbiosis". It's just another example of facultative lichenization, which has already been observed in species quite widely scattered across the fungal kingdom. That to me doesn't count as a "new type of coexistence". The actual research behind the headline is valuable and entirely worthy of publication (I've made similar contributions myself), my critique relates to the headline, the angle of the reportage.
contingo
·3 tahun yang lalu·discuss
I'm skeptical that this discovery amounts to a "new type of coexistence". Fungi that are facultatively lichenized (having growth forms that include or exclude algae) have been known about for a long time, as have various stages of sophistication of the lichenized condition. I can find references dating back to at least the 1980s that describe various kinds of facultative lichenization. The authors' insistence that the symbiosis is not a lichen just because the mycobiont (fungal partner) has a free-living form is suspect: previous literature makes no such distinction. The relevant distinction here is not between lichen vs. non-lichen, but facultative vs. obligate lichenization. The observation that the mycobiont can be free-living and "does not depend on its alga for nourishment" does not imply that it doesn't derive nourishment from its algal partner once the partnership is established.

There's no major news here that I can see. The main value of this research is simply that it provides the first description of facultative lichenization occurring in a particular group of under-studied fungi (corticioid basidiomycetes).
contingo
·3 tahun yang lalu·discuss
From the article:

>The donated shoes that ended up in Indonesia have added to a flood of illegal second-hand clothing pouring into that developing country, according to a senior government official there, who said such cast-offs pose a public health risk, undercut its local textile industry and often pile more waste into its already bulging landfills.
contingo
·3 tahun yang lalu·discuss
Many different groups of fish have independently evolved locomotion by "walking" on modified pectoral fins. One of my favorite examples are the bamboo sharks, among which are some pretty recently described species: https://en.wikipedia.org/wiki/Hemiscyllium_halmahera
contingo
·4 tahun yang lalu·discuss
It's woefully wrong for something in the primary literature. Yes, I understood what information they were sloppily failing to be precise about. If I were refereeing this paper I'd insist on a correction.
contingo
·4 tahun yang lalu·discuss
From the introduction, which starts by trying to give some wider taxonomic context:

>The genus Ilex comprises about 450 species growing in the tropical regions of South America and Asia. Ilex trees are located exclusively in South America...

The roughly 500-600 species in the genus Ilex are commonly called hollies and include the European Christmas holly, I. aquafolium. The genus overall has a worldwide distribution over both tropical and temperate regions, there is no particular concentration of diversity in the South American tropics. Strange to get basic facts so wrong in the opening sentences.
contingo
·4 tahun yang lalu·discuss
SALT_VERSE just uses still images generated by DALL•E-2 and Midjourney. They're animated using techniques that have already been around for a long time: panning around and zooming in and out of a larger frame, fake raster-to-3d effects (auto projection mapping), typical After Effects transitions. There are some overlaid face animations done with something along the lines of NVIDIA's Audio2Face. None of it is video generated by SD, DALL•E-2 and Midjourney.

There have been some actual video explorations of SD's latent space, this example amazes me: https://twitter.com/karpathy/status/1559343616270557184
contingo
·4 tahun yang lalu·discuss
The biological term "symbiosis", by itself, in the strict sense, doesn't imply a benefit for both parties, it just describes a persistent and physically close association between two species. Hence parasitism or commensalism are also forms of symbiosis and so are associations which are not obligate, but facultative (both bionts can live without the other, however prevalent the association). "Obligate symbiotic mutualism" is the category for what you're describing. "Endosymbiosis" implies such an integrated relationship that it is at least obligate for the endosymbiont. In this human-mite case there are various claims of benefits and drawbacks to humans from the relationship, and the symbiosis is certainly already obligate for the mites.
contingo
·4 tahun yang lalu·discuss
Psilocybin-producing mushrooms are widely dispersed across the clade of all other true mushrooms and their genomes clearly show there is no great mystery about their evolutionary history or relationships to other fungi. Modern phylogenetics completely discredits panspermia as an origin for particular species or groups of fungi: they all share a single common ancestor and they are all connected to our single Tree of Life as with every other known lifeform on Earth.
contingo
·4 tahun yang lalu·discuss
Tunicates evolved long before animals that you would recognize as typical vertebrates. In their free-swimming larval state, tunicates do have a "notochord", or nerve chord, running along their head-tail axis. This structure is a kind of proto-spine. The evolution of true vertebrates proceeded from this condition by neoteny, the retention of larval traits in the adult body plan. Pyrosomes look so bizarre compared to a layman's notion of what a chordate should look like because they are colonial aggregations of lots of individual adult tunicates that have resorbed their notochords (I'm pretty sure that's the case, despite what the photo description says).