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That's a rather naive take that you're attacking all of "biology" with. The article doesn't even state what you criticize it for - it doesn't say that there is
by svara 5y ago
That's a rather naive take that you're attacking all of "biology" with. The article doesn't even state what you criticize it for - it doesn't say that there is no such thing as a tree, it says there is no such thing phylogenetically.
All of these systems of categorization are necessarily arbitrary in a way, since all of life is a big messy tangle of related organisms, and there is nothing to clearly tell you where to draw lines to separate them. That's the source of your confusion right there. Turns out, groupings that seem obvious to someone who hasn't looked closely can be really difficult to delineate clearly.
So, biologists try to define rules by which to do that, which they can apply unambiguously. One of the possible rules to apply is that groups should be paraphyletic, i.e. only contain (some of the) organisms with a shared common ancestor, or monophyletic, i.e. contain all of the organisms with a shared common ancestor.
Other groupings do not fulfill those criteria, those are called polyphyletic. Grouping organisms that way has somewhat gone out of fashion, now that evolution is well understood. What this article is saying is that trees form a polyphyletic group. In addition to that, even just defining a group (for example, based on structural or functional properties of the plant) that neatly maps to what people usually consider to be a "tree" is harder than it sounds. Since all of that might be surprising, you see it here on HN.
- repsilat 5y ago> What this article is saying is that trees form a polyphyletic group. This example seems reasonable in that way because there isn't some parallel definition of "tree". A layman, on hearing that (according to evolutionary biologists) "birds are dinosaurs" might reasonably assume that evolutionary biologists will also say that dolphins are fish. Alas, no -- "dinosuar" has a parallel phylogenetic definition that differs from the lay one, but "fish" doesn't. Botany is a source of this sort of confusion a lot. Raspberries and strawberries and blackberries are culinary berries, but not botanical berries. (A tomato is a botanical berry, though. -EDIT, said culinary originally.) I'm of two minds about it. If you need a word, maybe it's best to use an existing one when there's a large overlap. But then again, the closeness of many legal terms ("murder", say) to their lay definitions arguably causes more confusion when those definitions differ. With biologists "just assume their meaning is totally different to yours" is a good heuristic, and with lawyers (or mathematicians talking about "knots" and "sets") the similarity causes perhaps more difficulty.
- jessaustin 5y agoWhat sort of berry is a tomato? I would have thought culinarily it would be a vegetable.
- intuitionist 5y agoIt’s a botanical berry but a culinary vegetable (as are the other fruit we eat from the Solanaceae)
- repsilat 5y agoWhoops, corrected, thanks.
- jameshart 5y agoI mean, dolphins are fish, in the sense that the most recent common ancestor of all modern fish is also the common ancestor of all modern dolphins. Very few animals aren’t fish in this sense though. Birds are also fish. What’s surprising is that you can exclude sharks and rays from your definition of ‘fish’ and this statement will still be true - you are more closely related to a salmon than a salmon is to a shark.
- goldenkey 5y agoIt's not just a rooted tree, it has crossovers and cycles. Trying to draw boundary boxes is a fools hardy.
- jameshart 5y agoThis is true, when you zoom in closely, but when you zoom out, it is quite treelike. phylogeny isn't useless just because the process of speciation isn't instantaneous.
- User23 5y agoIt’s very helpful to learn to recognize lumper versus splitter arguments. Pointing out that lumping things together or splitting things apart is arbitrary just isn’t very interesting. What is interesting is why some things are lumped and some are split. For example why are polar bears and grizzly bears considered different species? They can breed just fine after all.
- lolsal 5y agoI am not the parent and I don't speak for the parent, but I think I share some of the same sentiment. I'm not confused about the categorical parts of biology. I don't understand it all, but that's OK, I don't need to. What's irritating is the pedantry that comes from articles like this. If I wrote an article like, "There's no such thing as a strawberry, cryptographically," I imagine it would be entirely uninteresting. If I write a tree categorization algorithm that categories what I call a "tree" as something else, my algorithm would be buggy.
- svara 5y agoI guess people who make precisely classifying millions of objects their job need to be a little on the pedantic side to do that well. ;) But, in all seriousness, I didn't think the article was like that at all. The title is meant to grab your attention and then tell you lots of (to me, at least) interesting things about the evolution of trees. If you were able to write insightfully about strawberries from a cryptography perspective, that title you suggested might be completely fine. That said, I, too, remember people telling me things about how X wasn't actually Y because ... IMO, these types of arguments come across as pedantic when they're framed as basically being just about using words the right way, without also telling you something deeper about why something looks like an X but in many non-obvious ways is closer to a Y. My favorite example of that is the statement "Black is not a color". I heard that a lot as a child, and I would agree that that is unnecessarily pedantic. Learning about how color perception works, and how black is unlike other colors, is still super interesting.
- lolsal 5y agoYou make good points and I agree with all of them!