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There’s no such thing as a tree (phylogenetically)

eukaryotewritesblog.com

71–80 of 137 posts

Re: There’s no such thing as a tree (phylogenetically)

#71
Fascinating article, but I think it could benefit from some more examples. Since it mentions "a tree evolving into a dandelion (or vice-versa)" and then a paper about wood evolving independently at least 38 times in the Canary Islands, the perfect example is Sonchus Canariensis (https://www.smgrowers.com/products/plants/plantdisplay.asp?p..., better picture: https://garden.org/pics/2014-03-30/Kelli/5ef4db.jpg). I saw this plant during a hike on Tenerife a few years ago and found it so fascinating that it has stuck in my mind ever since. It's basically a colony of dandelions (ok, they're a bit larger, but still clearly dandelion-like) growing on long woody stalks. Not quite a tree yet, but definitely a shrub. I guess its peculiarity of only having leaves at the tip of its "branches" limits its growth, because the water circulation in a "tree" is made possible by the negative pressure produced by water evaporation on the leaves, so a "branch" can only get so long with leaves only at its tip?

And, since it later also mentions theoretical "insect birds"... well, there are some insects who are regularly mistaken for hummingbirds: https://en.wikipedia.org/wiki/Hummingbird_hawk-moth. In photos you can quite clearly see that it's an insect, but if you see it in real life it hovers around flowers just like a miniature hummingbird, and it's a bit large and bulky for a flying insect, so the confusion is understandable. BTW this is also an example of convergent evolution, and it's interesting that these moths don't exist on the American continent, where the actual hummingbirds have occupied this ecological niche.

Re: There’s no such thing as a tree (phylogenetically)

#72
post #56

Earlier quoted context omitted.

A good reminder that the map is not the territory. Lately I've started to see more and more "categories" in general as a very human construct, probably made to save on processing power when thinking about things. Reality is hard and very complex and you can't be thinking about all the details all the time.

Categories are an optimization. It is also a leaky abstraction and there are a large number of errors in our thinking due to this optimization, which is often premature.

I'm not sure that it's premature. We use categories all the time, the time when they fail us seem to be rare in proportion.

Re: There’s no such thing as a tree (phylogenetically)

#73
post #9

I don't get the premise of the article. A tree is just a growth shape of a plant (plants are quite flexible regarding growth shapes, and often adapt to the environment), and a category that our minds place a plant species into. And its clearly an ancient ability common to all vascular plants to develop woody tissues. So why would we expect the tendency of a plant to become a tree to depend on its position in the phyl…

I was under the impression that what made a tree was its woodenness so I was probably more of the target audience, and was impressed by the article.

You’re right that is what makes a tree. But don’t you feel that it’s obvious that different lineages of plants could acquire, and lose, woodenness independently of each other? And therefore 100% unsurprising that “tree” is not a monophyletic group.

Re: There’s no such thing as a tree (phylogenetically)

#74
post #9

I don't get the premise of the article. A tree is just a growth shape of a plant (plants are quite flexible regarding growth shapes, and often adapt to the environment), and a category that our minds place a plant species into. And its clearly an ancient ability common to all vascular plants to develop woody tissues. So why would we expect the tendency of a plant to become a tree to depend on its position in the phyl…

Precisely. I think this has been on HN before, or if not then another “Wow you’re gonna be surprised by this — trees aren’t monophyletic!” article. Given all the surprising examples of convergent evolution, and given human tendencies to give vernacular names to paraphyletic groups, and given that it’s obviously easy for plant lineages to increase or decrease the woodiness of their stems, it is baffling that anyone would think it surprising that “trees” aren’t monophyletic.

Re: There’s no such thing as a tree (phylogenetically)

#75
post #58

Earlier quoted context omitted.

And killer whales. Big, carnivorous and hooved with lots of teeth. Those are ungulates too. Interestingly enough, Judaism uses rumination, in part, to determine whether an animal is okay to eat. It was called “chewing their cud”. Pigs don’t do this and that’s why they’re not kosher. I suspect this was the inspiration for pork being haram in Islam but it’s explicitly prohibited by name, rather than by property. I’m no…

> And killer whales. Is that true? The wikipedia page on Ruminants shows the Cetacea outside of the group labeled Ruminants. https://en.wikipedia.org/wiki/Ruminant

Ah, I meant they’re cetaceans and therefore ungulates, albeit non-herbivorous. Should have made that clearer, sorry!

Re: There’s no such thing as a tree (phylogenetically)

#76
post #66

Earlier quoted context omitted.

Also, you're a fish. When people talk about fish, they mean "fish that aren't tetrapods", because cladistically speaking, tetrapods (birds, reptiles, mammals) are fish too.

I dispute that. Speaking as a vegetarian, I think the key problem is that a lot of people don't know WTF a fish is. Q: Do you know what's the best gift to give a vegetarian who eats fish? A: A dictionary.

I don't see how the culinary definition of fish is related to cladistics.

Even if they were, I don't see what you dispute, because they agree on this point; if "vegetarian" means "avoid meat" and "meat" means "flesh of animal", then vegetarian also means to avoid fish. Come to think of it, eggs would also be included in that definition.

Re: There’s no such thing as a tree (phylogenetically)

#78

Earlier quoted context omitted.

I was under the impression that what made a tree was its woodenness so I was probably more of the target audience, and was impressed by the article.

You’re right that is what makes a tree. But don’t you feel that it’s obvious that different lineages of plants could acquire, and lose, woodenness independently of each other? And therefore 100% unsurprising that “tree” is not a monophyletic group.

After reading this article yes, but obvious? No at all.

Re: There’s no such thing as a tree (phylogenetically)

#79
post #66

Earlier quoted context omitted.

I dispute that. Speaking as a vegetarian, I think the key problem is that a lot of people don't know WTF a fish is. Q: Do you know what's the best gift to give a vegetarian who eats fish? A: A dictionary.

I don't see how the culinary definition of fish is related to cladistics. Even if they were, I don't see what you dispute, because they agree on this point; if "vegetarian" means "avoid meat" and "meat" means "flesh of animal", then vegetarian also means to avoid fish. Come to think of it, eggs would also be included in that definition.

I don't think eggs are the flesh of an animal? That would seem to stretch the definition of "flesh" quite a bit, wouldn't it?

Re: There’s no such thing as a tree (phylogenetically)

#80

Earlier quoted context omitted.

I don't see how the culinary definition of fish is related to cladistics. Even if they were, I don't see what you dispute, because they agree on this point; if "vegetarian" means "avoid meat" and "meat" means "flesh of animal", then vegetarian also means to avoid fish. Come to think of it, eggs would also be included in that definition.

I don't think eggs are the flesh of an animal? That would seem to stretch the definition of "flesh" quite a bit, wouldn't it?

It's an animal cell, I suppose.
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