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There’s no such thing as a tree phylogenetically (2021)
- MiguelVieira 4y agoI like David Allen Sibley's definition of a tree: "If you can walk under it, it's a tree; if you have to walk around it, it's a shrub".
- bee_rider 4y agoBut you still have to walk around trees, at least the trunk part. Maybe a tree is a subset of shrubs. Maybe shrubs are graphs.
- mcv 4y agoI like that definition, but: is a tree with very low branches (like a fir) really a shrub? Does a fallen tree become a shrub?
- tshaddox 4y agoAnd are walls, houses, rivers, people, etc. all shrubs?
- DeadMouseFive 4y agoBut what about plants that can be pruned to both shapes?
- agentwiggles 4y agoTrubs, obviously
- jmull 4y agoShreebs.
- jameshart 4y agoChristmas trees: actually Christmas shrubs.
- hinkley 4y agoChristmas trees aren't just murdered trees, they're murdered baby trees.
- bagacrap 4y agoChristmas Shrub then?
- euroderf 4y agoMaybe Hanukkah Bush is a totally valid taxonomic classification.
- jadbox 4y agoConvergent evolutions are fascinating. It also gives me a hope that we'll find other non-earth life that will have some things axiomatically common with us (due to convergence).
- basch 4y agoOne question I’ve always had with the Drake equation is if it needs another line for scale. That we are roughly the same size, and experience time at roughly the same rate. Would we notice an alien civilization sending a signal with a small message over the course of hundreds of years, at a bit a century frequency? Would we recognize each other as life if one is the size of a galaxy or the size of an atom?
- timdellinger 4y agoI second the suggestion at the bottom of the (very enjoyable) post, pointing readers to the Crime Pays But Botany Doesn't content on YouTube - their passion and their approach are fantastic.
- pbhjpbhj 4y agoMinor warning, to my recollection, their language can be a little robust (that's a euphemism for sweary), but the creator is very interesting to listen to, and clearly very knowledgeable. Definitely a recommendation. If anyone knows of something similar for UK flora and fauna then please point me to it.
- selimthegrim 4y agoAre they a botanist anymore?
- donkeyboy 4y agoVery fun article. Convergent evolution is so cool. At the end, the author asked: why don’t plants also evolve into grasses? Would like to hear if anyone knows. If you look at onion or garlic growing, it basically looks like a very long piece of grass.
- mcv 4y ago> why don’t plants also evolve into grasses? Perhaps they're doing exactly that. But grasses evolved far more recently than trees.
- mannykannot 4y agoIf all plant life evolved into grasses, that would create an opportunity to do something different - to grow taller than grasses are able, for example. Monocultures are not optimal.
- blululu 4y agoTangentially related, but grasses are, in fact, a very recent evolutionary turn. We live in a very grass heavy epoch to the extent that it is hard for me to imagine a world with out grasslands. In some sense grasses seem primitive and foundational to us compared to a flowering tree like the magnolia, but no - grasses are actually really complicated and impressive organisms that filled an unexpectedly large niche.
- LudwigNagasena 4y agoThere is such thing as a tree. There is such thing as a fish. Maybe even conceding that dolphins and whales aren’t fish was already too much. After all, cladistics isn’t everything.
- omginternets 4y agoWhat alternative are you suggesting? Some kind of functional grouping?
- NegativeLatency 4y agoProbably something along the lines of “if it quacks like a duck then it’s a duck”
- a3n 4y agoThose aren't trees either.
- embedded_hiker 4y agoThey are, if they are made out of wood.
- bregma 4y agoA witch! Burn her! Burn her!
- embedded_hiker 4y agoFortunately, we know much more about science than they did when the Monty Python movies were made.
- MichaelZuo 4y agoAnd who will arbitrate disagreements? There are billions of dollars of peanuts, fish, etc., being traded across the world every week.
- raldi 4y agoPineapple is “definitely a tree”?
- jtsuken 4y agoCame here to say the same: "wtf how are bananas and pineapples trees? Shall we get him to look up the pictures or ask some AI model to get the images of wikipedia and to classify them?" There are fern trees (Tree Fern to be precise), but they only grow in tropical regions. Bananas and pineapples are clearly grass with huge leaves.
- roelschroeven 4y agoI think it's interesting how I discover in this comment section that many people use the word grass for any member of the order Poales, where I would only use it for members of the family Poaceae, and even then only when speaking in very general terms when it comes to things like bamboo. But bananas? Who calls bananas grasses? They're not even in Poales!
- jmull 4y agoI guess plants are awfully good at finding niches, but with the sun up there and ready lignin, they always come back to growing tall and strong.
- photochemsyn 4y agoHumans care about wood, so they made tree (thing which produces wood) a category, as it can be used to build bridges, ships and other structures. Wood being dense also made it a better feedstock for charcoal (one can use grass, however). As far as why trees don't seem to evolve into grasses, (or grasses into trees), it might be all about C3 vs C4 carbon metabolism, the latter being a complex structural system that pre-concentrates atmospheric CO2 before feeding it into the photosynthetic biochemistry (which is the right way to do artificial photosynthesis as well). This is apparently difficult to do in trees? https://pubmed.ncbi.nlm.nih.gov/32409834/ https://pubmed.ncbi.nlm.nih.gov/32409834/ > "Since C4 photosynthesis was first discovered >50 years ago, researchers have sought to understand how this complex trait evolved from the ancestral C3 photosynthetic machinery on >60 occasions. Despite its repeated emergence across the plant kingdom, C4 photosynthesis is notably rare in trees, with true C4 trees only existing in Euphorbia." And here we have the world's largest Euphorbia: https://www.wikidata.org/wiki/Q5851367 https://www.wikidata.org/wiki/Q5851367
- jameshart 4y agoBamboo being the obvious exception of a grass that really wants to be a tree.
- mankyd 4y agoAnd Palm "Trees".
- throwawaylinux 4y agoPalms are not grasses.
- mankyd 4y agoIs that true? Most of the internet says they are, and I first learned it from a local guide several years back.
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- causi 4y ago"Trees are not a clade" is a much more accurate description. Same as ravens, fish, and frankly most categories of thing.
- thanatropism 4y agoWelcome to "A thousand plateaus" by Gilles Deleuze and Felix Guattari. ATP is a political book, albeit not a book about politics. But in the process of building their radical political theory, they build a radical general systems theory that's u-n-m-a-t-c-h-e-d. We have no choice but to study it. This doesn't do it justice, but it's a fair beginning. https://en.wikipedia.org/wiki/Rhizome_(philosophy) https://en.wikipedia.org/wiki/Rhizome_(philosophy) This is an illustrated audio reading of the first chapter of ATP (the one dedicated to rhizomes): https://www.youtube.com/watch?v=0XYc2scuJrI&t=64s https://www.youtube.com/watch?v=0XYc2scuJrI&t=64s
- echelon 4y agoWhen I read Wikipedia (or any treatment) on philosophy, I can't help but feel like laymen are trying to science without getting their hands dirty and while trying to sound fancy. I know that's the wrong take, but I can't get over it. The linked article for this thread is about how "tree" biology keeps springing up and disappearing - the molecular biology, genetics, convergent evolution -- and how the human concept of "tree" doesn't really map cleanly. All of that, to me, is intuitive. But philosophy is lost on me. Neither your linked Wikipedia article or the article on the book you suggest [1] make much sense to my non-philosophical science brain. My eyes just glaze over. [1] https://en.wikipedia.org/wiki/A_Thousand_Plateaus https://en.wikipedia.org/wiki/A_Thousand_Plateaus
- chordalkeyboard 4y agoD&G are a bad place to start with philosophy. I recommend watching these lectures by the late Professor Rick Roderick for a more accessible introduction: http://rickroderick.org/101-socrates-and-the-life-of-inquiry-1990/ http://rickroderick.org/101-socrates-and-the-life-of-inquiry...
- soco 4y agoIs D&G an established term for Deleuze&Guattari? Because for me it will always decode to Dolce&Gabbana...
- salicideblock 4y agoFrom 2021. Previous discussions https://news.ycombinator.com/item?id=27094382 https://news.ycombinator.com/item?id=27094382 https://news.ycombinator.com/item?id=29621646 https://news.ycombinator.com/item?id=29621646 Cool article either way.
- dang 4y agoThanks! Macroexpanded: There’s no such thing as a tree (phylogenetically) - https://news.ycombinator.com/item?id=29621646 https://news.ycombinator.com/item?id=29621646 - Dec 2021 (132 comments) There’s no such thing as a tree, phylogenetically - https://news.ycombinator.com/item?id=27094382 https://news.ycombinator.com/item?id=27094382 - May 2021 (207 comments) There’s no such thing as a tree (phylogenetically) - https://news.ycombinator.com/item?id=27026812 https://news.ycombinator.com/item?id=27026812 - May 2021 (1 comment)
- eternalban 4y ago> Axolotls The Axolotl tanks of Tleilaxu. I wonder if Frank Herbert got that from these creatures or is this some crazy coincidence that Axolotls are subjected to genetic 'shape shifting'.
- anonymouskimmer 4y agoGiven what the fictitious axlotl tanks actually are I don't think it can be coincidental. Wikipedia on Axolotls > It is unusual among amphibians in that it reaches adulthood without undergoing metamorphosis.
- dav_Oz 4y agoUseful abstractions. Exploring their usefulness can be fun (the pedantic kind) and even sometimes illuminating. Obviously right from the start "taxonomy" itself is arbitrary. A more universal tool than naming, establishing branches, starting and end points is the concept of "most recent common ancestor" [0]. From that nameless unclassified vantage point I find it interesting to see (as OP pointed out) how "woodiness" or "treeness" evolutionary speaking is clearly a "strategy" (convergent evolution) and nearly impossible to chase down "phylogenetically" through MRCAs. Intuitively before reading this article I would have guessed this to be more straightforward. [0]https://en.m.wikipedia.org/wiki/Most_recent_common_ancestor https://en.m.wikipedia.org/wiki/Most_recent_common_ancestor
- dekhn 4y agoI worked in phylogenetics for a while and it was a pretty confusing area. Originally, phylogenetic trees (not the biological trees that are the subject of the OP) were created by finding physical features (yes, just like ML) and using those to build a semi-supervised tree-structure of classifications. However, eventually we began to use DNA sequences to compare organisms, which restructured the tree in many ways, even close to the root. It was a controversial time as the the historical physical-feature classifier group was certain their way was right, and same for the DNA folks. I sort of assumed that the DNA would be a much higher quality source for clustering but it hasn't really always worked out that way.
- bee_rider 4y agoI guess it depends on on why you are doing the clustering, right? If you want to cluster animals that sort of fuzzily behave similarly together — if it looks like a duck and walks like a duck, it probably acts like a duck, haha.
- suchire 4y agoExcept phylogeny generally was used to categorize how hereditarily related things were. Whether sequence alignment or physical taxonomy are better determinants is perhaps an open question in some cases, although I’m firmly on the side of sequence alignment, since DNA is an important component of inheritance
- Kaijo 4y agoThe side you are on has already won. Sequence data are universally accepted in systematics as the ultimate arbiters of evolutionary relationships, just delve into the modern classification of any extant group. One example of where molecular evidence overturned physical evidence long thought to be unambiguous, leading to a complete and essentially uncontested taxonomic overhaul: coprinoid mushrooms. Morphological characters are still used in paleontology for obvious reasons, but again within a higher-level framework provided by molecular phylogenetics.
- stevenjgarner 4y agoAm I the only one drilling down in this thinking it might be about tree data structures? Not really having a clue what "phylogenetically" might mean, but kind of assuming it was about "those" other natural trees.
- taliesinb 4y agoInteresting article, though I thought this was going to be about the fact the the "phylogenetic tree" is not in fact a tree but a hypergraph, owing to the existence of sexual reproduction.
- dhosek 4y agoI’ve been thinking it would be fun to build a simple game where you get three organisms and you’re supposed to identify which two are most closely related, for example, strawberry, apple, orange, or hippopotamus, horse, rhinoceros or for the big challenge, squid, earthworm, fish.
- jschveibinz 4y agoSounds like fun to me.
- deleted 4y ago[deleted]
- crazygringo 4y agoI love that idea. If you turn it into a mobile friendly site, and then reveal the common ancestor of the two closest, and the ancestor of all three, that would turn into basically my favorite educational addiction ever. Bonus points if there are maps showing world geographical distributions.
- dhosek 4y agoTrying to track down common ancestors would be a challenge (not to mention that in most cases the common ancestor is unknown), I figure I’d be instead indicating how far up the kingdom-phylum-class-order-family-genus-species hierarchy you need to go.
- SamBam 4y agoReminds me a little of the fact that "vegetable" is not a botanical term. People who say "tomatoes are fruits, not vegetables" are guilty of performing an incorrect hypercorrection. Tomatoes are vegetables just as cucumbers, green beans, asparagus, lettuce, fennel and carrots are. "Vegetables" is a culinary and dietary term, not a biological one.
- commandlinefan 4y agoWell wait a minute, then, biologically what are cucumbers, green beans, asparagus, etc.? They're not fruits.
- scotteric 4y agoCucumbers and green beans are fruit. Fruit is a botanical term for the structure that a flower grows into once fertilized. Fruit has seeds.
- NovaDudely 4y agoThe best definition was from Dr Karl on ABC radio (Australia). If you put it with ice cream it is a fruit, if you put with a roast it is a vegetable.
- anonymouskimmer 4y agoWhat is pineapple then?
- jdlyga 4y agoThis reminds me of carcinisation. Where natural selection tends to heavily favor crab-shaped animals even though they come from different lineages. Natural selection seems a lot like physics. Given similar initial conditions and a population of organisms, you’re going to get similar results across groups after a period of time.
- jonathankoren 4y agoThere’s also no such thing as a fish. https://chireviewofbooks.com/2020/04/15/why-fish-dont-exist-lulu-miller/ https://chireviewofbooks.com/2020/04/15/why-fish-dont-exist-...
- mig39 4y agoAlso a fact on one of the earliest QI episodes, and a popular podcast: https://www.nosuchthingasafish.com https://www.nosuchthingasafish.com
- throwawaaarrgh 4y agoI'm going to save this chart just to mess with plant nerds at parties. (lol jk i don't get invited to parties.)
- DonaldFisk 4y agoSurprised there's no mention of Lepidodendrons. OK, they're long extinct, but they were trees, even though they were closer genetically to club mosses and quillworts than any modern trees. > First, what is a tree? It’s a big long-lived self-supporting plant with leaves and wood. Also, do pineapple and banana plants have wood? I didn't think so.
- peter303 4y agoPoet Joyce Kilmer would be disappointed.
- wardedVibe 4y agoMy partner, who is a biologist, hates this take as a mostly grammar trick. Then again, she has no patience for philosophy in general, so that probably explains it.
- deleted 4y ago[deleted]
- kevinwang 4y agoI think the awesome takeaway of this post isn't about the naming and categorization of things (like "tomato is a fruit" or "humans are fish") but the shocking (to me, at least) fact that trees evolved and unevolved so many different times, and not just once.
- abudabi123 4y agoDid the fish drive the trees out of water in the first place?
- quickthrower2 4y agoIs a tree a burrito or a sandwich?
- swalling 4y agoBotany is fun in part because it has its own arcane descriptive vocabulary. One of my favorite botanical words is "arborescent", meaning resembling a tree. There are whole genera where some of the related plants are trees and others aren't. There's Aloe vera, which you can keep in a pot on your windowsill, and then there is https://en.wikipedia.org/wiki/Aloidendron_barberae https://en.wikipedia.org/wiki/Aloidendron_barberae which can be 60 ft tall. A bunch of the tree aloes got split off somewhat recently, but there are a lot of genera where some have tree forms and others are tiny. Dracaena is another one, where you have the "snake plant" that's probably the most common office plant in the world, and it got lumped together with https://en.wikipedia.org/wiki/Dracaena_draco https://en.wikipedia.org/wiki/Dracaena_draco in one genus. Taxonomy is wild.
- GolDDranks 4y agoThis is something that struct me before as I was enjoying the Japanese Hanami (having a picnic under flowering trees) festival, and I once attempted to verify whether my understanding was correct, but unfortunately my Google-fu failed me at the time, since a "tree" happens to have a troubling double-meaning as a tree of clades in phylogeny, or as a physical tree; so it's very hard to search whether "physical trees form a phylogenic tree". Glad to have that verification now.
- isaacfrond 4y agoThis page has been on HN seven times! https://hn.algolia.com/?q=+tree+%28phylogenetically%29 https://hn.algolia.com/?q=+tree+%28phylogenetically%29 Three of which are with identical links, by the way, why isn't this filtered out by HN's dupe detection system?
- yesenadam 4y agoDang explains: https://news.ycombinator.com/item?id=32359993 https://news.ycombinator.com/item?id=32359993 https://news.ycombinator.com/item?id=31574948 https://news.ycombinator.com/item?id=31574948