from Hacker News

The Jellyfish Problem

by gruseom on 8/28/20, 9:11 PM with 11 comments

• by ncmncm on 8/28/20, 11:42 PM

  We still have the problem of the ctenophores. "Comb jellies", they used to be, until it turned out they have practically nothing in common with jellyfish except transparency and radial symmetry. Or with anything else.

  They use proteins similar to those used by other animals, but for different things. Some people think they evolved muscles and nerves entirely independently of other animals. Some people think they fell from the sky.

  Whatever you think, they are astonishing in every detail. Watch videos of Beroe if you have any doubts.

• by frabbit on 8/29/20, 12:56 PM

  A good tour of the problems of phenotypic classifications -- which reached their heyday in the funfair of cladism. Always reminds me of Terry Pratchett's jokes about banana classification:

  https://www.goodreads.com/quotes/6870748-yes-sir-but-the-lib...

• by divbzero on 8/29/20, 6:53 AM

  The article didn’t mention phylogenetic analysis of jellyfish genes or genomes, e.g. using 16S rRNA. [1]

  [1]: https://en.wikipedia.org/wiki/16S_ribosomal_RNA

  A brief search didn’t yield anything on jellyfish phylogeny for me, would be curious if anyone else has information on this.

• by perl4ever on 8/29/20, 2:13 AM

  "Since nothing could will itself to move without some sense of where it wanted to go"

  https://www.farmersalmanac.com/maple-copters-everywhere-2158...

• by cortesoft on 8/29/20, 4:41 AM

  There is no 'true' category for anything.

  The Categories Were Made For Man, Not Man For The Categories

  https://slatestarcodex.com/2014/11/21/the-categories-were-ma...

• by naringas on 8/29/20, 1:10 AM

  reminds me of https://meaningness.com/eggplant/definition