On Being a Fish

inference-review.com

13 points·smadge··8 comments

> The tree of life is almost entirely composed of binary branchings. The occasional, strange exceptions are fascinating, but rare enough that they need not concern us here.

What are they?

I'm guessing they're probably referring to https://en.wikipedia.org/wiki/Horizontal_gene_transfer

Also, probably hybridization.

https://en.m.wikipedia.org/wiki/Hybrid_speciation

Here's one: https://en.wikipedia.org/wiki/Ring_species

You also can't come to a good definition of the word "species".

We like to categorize things. Sometimes arbitrarily. What's wrong with that?

I don't see the point of this article.

Well, the choice is between an arbitrary category with a complex definition that doesn't provide any insight to its evolution history, to one that is strictly defined by nature itself and provides lots of evolutionary insight. Generally speaking you should prefer things that assume less and explain more.

No, there are many choices, each with subtle distinctions. What's your definition?

Nature does not strictly define species, and how does it provide evolutionary insight exactly?

There's a misunderstanding. I agree that there is no good definition of species. However, there is a good definition of clade, taxon, or monophyletic group. The author is suggesting that paraphyletic and polyphyletic taxonomical groups that are based on biases, intuition, or morphological similarities. We should distinguish between groups based on traits and groups based evolutionary history, and not conflate the two.

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