Please stop calling them pond scum

Gonium pectorale. Credit: Kansas State University.

Gonium pectorale. Credit: Kansas State University.

Yes, they live in ponds; no they don’t form any kind of scum. The press release from Kansas State on the Gonium genome paper, which is reprinted here, here, and here, is titled “Pond scum and the gene pool: One critical gene in green algae responsible for multicellular evolution, understanding of cancer origin.” Gonium forms planktonic colonies of (usually) 8, 16, or 32 cells that swim under their own power and exhibit phototaxis (they’ll swim toward a light source). They are not pond scum. ‘Algae’ and ‘pond scum’ are not synonyms, dig? Leaving aside the distinction between algae and cyanobacteria, calling Gonium pond scum is like saying pineapples are lemons (because both are fruits).

Also…cancer origin, really? You went there? The word ‘cancer’ does not appear in the paper except in the funding acknowledgements (Bradley Olson is partly funded by the KSU Johnson Cancer Center).

Heads I win; tails you lose: Evolution News & Views on Gonium, part 2: Model systems and gene duplication

Figure 2 from Hanschen et al. 2016. (a) Predicted number of genes in each phylostratum (PS1–PS9) for Chlamydomonas, Gonium and Volvox. (b) Heatmap of transcription factor abundance for all green algae. Significant over- (+) and under-representation (−) in colonial/multicellular lineages (Gonium and Volvox) is denoted (G test of independence, α=0.05). Rows are clustered (left), an accepted phylogeny is depicted (top). (c) Phylogenetic analysis of gene family evolution. Bars to the left and right of the vertical axis denote the lost and gained gene families respectively, relative to its parental node. (d) Venn diagram of the species distribution of Pfam A domains unique to the volvocine algae.

Figure 2 from Hanschen et al. 2016. (a) Predicted number of genes in each phylostratum (PS1–PS9) for Chlamydomonas, Gonium and Volvox. (b) Heatmap of transcription factor abundance for all green algae. Significant over- (+) and under-representation (−) in colonial/multicellular lineages (Gonium and Volvox) is denoted (G test of independence, α=0.05). Rows are clustered (left), an accepted phylogeny is depicted (top). (c) Phylogenetic analysis of gene family evolution. Bars to the left and right of the vertical axis denote the lost and gained gene families respectively, relative to its parental node. (d) Venn diagram of the species distribution of Pfam A domains unique to the volvocine algae.

Erik Hanschen, the lead author on the Gonium genome paper, is also an old friend of mine from when we were both in Michael Doebeli’s lab at the University of British Columbia. He kindly agreed to write a guest post responding to Evolution News and Views‘ misunderstandings of his paper. Everything below the fold was written by Erik:

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Heads I win; tails you lose: Evolution News & Views on Gonium, part 1

Figure 6 from Hanschen et al. 2016. Multicellularity hinges on the evolution of cell cycle regulation in a multicellular context with subsequent evolution of cellular differentiation (here, cell size-based) and increased body size.

Figure 6 from Hanschen et al. 2016. Multicellularity hinges on the evolution of cell cycle regulation in a multicellular context with subsequent evolution of cellular differentiation (here, cell size-based) and increased body size.

Remember how I said they’re prolific? Before I’ve even had a chance to write up my thoughts on the Gonium genome paper, Evolution News & Views has already published theirs. The story has also been picked up by the Washington Post, New Historian, GenNews, and ScienceDaily (that last one looks like just a reprint of the press release from University of the Witwatersrand). By the way, the genome paper is open access, so you don’t need a subscription to see it for yourself.

We already know that cdesign proponentsists are not fans of research into the evolution of multicellularity, and that they have trouble understanding it. In an unsigned article on the Gonium genome at ENV, they admit that

After reading this paper, we’re none the wiser.

That’s too bad. I’m here to help.

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Gonium genome published

Figure 1 from Hanschen et al. 2016. (a) Evolution of cell cycle control (C), expanded ECM (E) and somatic cells (S) are denoted. (b) Micrographs of Chlamydomonas (green; scale bar, 10 μm), Gonium (blue; scale bar, 10 μm) and Volvox (black; scale bar, 25 μm) show morphological differences.

Figure 1 from Hanschen et al. 2016. (a) Evolution of cell cycle control (C), expanded ECM (E) and somatic cells (S) are denoted. (b) Micrographs of Chlamydomonas (green; scale bar, 10 μm), Gonium (blue; scale bar, 10 μm) and Volvox (black; scale bar, 25 μm) show morphological differences.

I haven’t read it yet and won’t have time today, but the Gonium pectorale genome paper just came out in Nature Communications! Erik Hanschen is the lead author, and the article is open access. I previously reported on Erik’s talk at Volvox 2015:

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