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Comment by __MatrixMan__ | Hacker News Reader

I was surprised to learn that two randomly selected trees are not likely to be more closely related than any two other randomly selected plants. They're not a family but rather a strategy that evolution has rediscovered several times separately.

If there is light-powered life on other planets, it has probably figured out how to tree also.

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There was a huge revolution in understanding taxonomy when we started actually genetically testing various organisms. Before then, we had to categorize things based on the fossil record and based on similar structures, but it turns out a lot of very similar looking things aren't actually more related to each other than they are to very dissimilar looking things.

I do think there's an argument to be made that there should be a paradigm that describe organisms that are functionally the same within an ecosystem but genetically quite different other than "convergent evolution."

I think the paradigm you're looking for is Plato's Theory of the Forms.

Half-joking.

I just think that while it's scientifically fascinating, and great as a fun fact to say "There's no such thing as trees actually, they're just related to various other plants" and "There's no such thing as fish, actually, they're all related to different other species" it's also useful to have a word that refers to all tall, woody plants or all gilled-vertebrates.

Either way, better Plato than Pliny.

The word "fish" historically meant more or less any animal in the sea, which to my understanding included whales, seals, sea turtles, shrimp, shellfish, starfish, jellyfish, etc.

Phylogenetically, there is also a relevant group, but we call them "chordates" instead.

>"There's no such thing as fish"

fun fact, your average bony fish is more closely related to us than it is to a shark

That would be interesting, a taxonomy of niches.

For an animal example with pretty specific niches, various kinds of tenrec look and behave very similarly to various types of hedgehogs and shrews, to the point that they can be mistaken for each other at a glance, but are in a completely different order of species.

And then there’s https://en.m.wikipedia.org/wiki/Carcinisation

We already have the concept of "tree", "grass", etc. it would just need to be formalized

https://en.wikipedia.org/wiki/Convergent_evolution

There's a lot we don't know about what life would look like on other planets, but there would be trees and there would be crabs.

> They're not a family but rather a strategy that evolution has rediscovered several times separately.

I don't think that is true. My understanding would be more "all angiosperms are trees, and the ones that aren't woody are sort of doing a neoteny. They still usually have "latent tree genes", and so it fairly "easy" to evolve back and forth between small herb and big tree.

Do you mean 2 randomly selected trees for the same specie?

Otherwise that statement is not surprising at all.

It’s somewhat surprising to me. If you take any two furry animals, they are more closely related to each other than to a lizard.

Not really true. Kiwi birds are very furry (unless you define furry as having mammalian hair, which sort of defeats the point) and are more related to lizards than to mammals.

Right, that was my thinking. Though frequently incorrect, it is intuitive that similar things are more closely related than dissimilar thing.

Well no, 2 randomly selected trees for the same species are quite likely to have a recent common ancestor (contrasted with, say, a tree and fish) because they're the same species.

I was under the mistaken impression that "tree" was a phylogenetic thing. Like, they're all descended from some distant great-grandmother-tree or something. The surprising thing was that this is not the case, and many separate species have all discovered how to tree individually.

Well, I suppose the more striking statement is that you can find two trees and two bushes such that there is a tree/bush pair that is closer related than the tree/tree pair.

Ginkgo biloba (Ginkgo/Maidenhair Tree) https://www.vdberk.com/trees/ginkgo-biloba-mascia/

Pinus strobus (White Pine) https://www.wildflower.org/plants/result.php?id_plant=PIST

Ephedra sinica (Chinese Ephedra/Ma Huang) https://www.inaturalist.org/taxa/135489-Ephedra-sinica

Juniperus horizontalis (Creeping Juniper) https://www.gardenia.net/plant/juniperus-horizontalis-blue-c...

I think visually the first two look alike and the last two look alike. I would phenotypically bucket them together. But the reality of genetic relation is different.

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