Seems like every time I doze off for a few years, someone goes in and rearranges the chairs at the top end of the phylogenetics charts.

The Kingdom called Chromalveolata contains water molds, ciliata, coccolithophores, various weird junk. They were one of the major divisions of eukaryotes, kingdoms.

However, I now discover that for years now the view is increasingly that Chromalveolata is not a clade: it is polyphylic. No clade can contain all of the members of Chromalveolata and not include for instance the Rhizaria.

So from here they either expand Chromalveolata to some mega-ultra Chromalveolata that includes everything descended from the MRCA of all ye-olde-Chromalveolata, or just give Chromalveolata up as a bad joke.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2610160/figure/fig1/

Some terminology I just learnt:
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Primary endosymbiosis

Used to describe the initial capture of a cyanobacterium by a eukaryotic cell that gave rise to the algae (see also endosymbiosis).

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Secondary endosymbiosis

An event in which a eukaryotic cell enslaves another eukaryotic cell that possesses a plastid derived from a primary endosymbiosis (see also endosymbiosis and primary endosymbiosis).

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Tertiary endosymbiosis

An event in which a eukaryotic cell enslaves another eukaryotic cell that possesses a plastid derived from a secondary endosymbiosis (see secondary endosymbiosis). This has occurred several times in the dinoflagellates, and the captured plastid is thought to have replaced a pre-existing Secondary plastid (see also endosymbiosis).

However, I now discover that for years now the view is increasingly that Chromalveolata is not a clade: it is polyphylic. No clade can contain all of the members of Chromalveolata and not include for instance the Rhizaria.

“polyphyletic”

HTH.

Help, it does, and my gratitude is only exceeded by my admiration.

> Seems like every time I doze off for a few years, someone goes in and rearranges the chairs at the top end of the phylogenetics charts.

I’ve noticed that too. It’s a side effect of genetic sequencing of single-celled eukaryuotes. Nobody could tell how far apart these were by sight alone without genetics, they were too distantly related to be sure of how far apart they were on the evolutionary tree without a genetic comparison.

mollwollfumble said:

> Seems like every time I doze off for a few years, someone goes in and rearranges the chairs at the top end of the phylogenetics charts.

I’ve noticed that too. It’s a side effect of genetic sequencing of single-celled eukaryuotes. Nobody could tell how far apart these were by sight alone without genetics, they were too distantly related to be sure of how far apart they were on the evolutionary tree without a genetic comparison.

Ah well, I suppose it is all progress.