Volvox 2015 meeting review available online

Fig. 1 from Herron 2016. Examples of volvocine species. A: Chlamydomonas reinhardtii, B: Gonium pectorale, C: Astrephomene gubernaculiferum, D: Pandorina morum, E: Volvulina compacta, F: Platydorina caudata, G: Yamagishiella unicocca, H: Colemanosphaera charkowiensis, I: Eudorina elegans, J: Pleodorina starrii, K: Volvox barberi, L: Volvox ovalis, M: Volvox gigas, N: Volvox aureus, O: Volvox carteri.

Fig. 1 from Herron 2016. Examples of volvocine species. A: Chlamydomonas reinhardtii, B: Gonium pectorale, C: Astrephomene gubernaculiferum, D: Pandorina morum, E: Volvulina compacta, F: Platydorina caudata, G: Yamagishiella unicocca, H: Colemanosphaera charkowiensis, I: Eudorina elegans, J: Pleodorina starrii, K: Volvox barberi, L: Volvox ovalis, M: Volvox gigas, N: Volvox aureus, O: Volvox carteri. A and B by Deborah Shelton.

The meeting review for the Third International Volvox Conference is now available online at Molecular Ecology (doi: 10.1111/mec.13551). The editors warned me ahead of time that the challenge for this paper would be to make it of broad interest to the readership of Molecular Ecology, so there is a lot of background information that will be old news to members of the Volvox community.

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Volvox 2015: taxonomy, phylogeny & ecology

Volvox africanus

Volvox africanus (from Herron et al. 2010)

The worst-kept secret among Volvox researchers is that the current volvocine taxonomy is a train wreck. Within the largest family, the Volvocaceae, five nominal genera are polyphyletic (Pandorina, Volvulina, Eudorina, Pleodorina, and Volvox). Of the remaining three, two are monotypic (Platydorina and Yamagishiella). Only the newly described Colemanosphaera is monophyletic with more than one species. The extent of the problem was suspected long before it was confirmed by molecular phylogenetics, and ad hoc attempts to deal with it have led to the existence of such taxonomic abominations as ‘sections,’ ‘formas,’ and ‘syngens.’ An overhaul is called for, but it is complicated by the aforementioned loss of type cultures.

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Why don’t we revise volvocine taxonomy?

Volvocine taxonomy is in a sorry state. Most nominal genera, and some nominal species, are almost certainly polyphyletic. More than once, I’ve been asked during a talk, “Why is Volvox scattered all over the tree?”

JPhycol2010Fig2a

Fig. 2A from Herron et al. 2010. The traits characteristic of the genus Volvox—asexual forms with >500 cells, only a few of which are reproductive, and oogamy in sexual reproduction—have arisen at least three times independently: once in the section Volvox (represented by V. globator, V. barberi, and V. rousseletii), once in V. gigas, and once or possibly twice in the remaining Volvox species. Branch shading indicates maximum-parsimony reconstruction (white = absent, black = present, dashed = ambiguous). Pie charts indicate Bayesian posterior probabilities at selected nodes. Numbers to the left of cladograms indicate log-Bayes factors at selected nodes: positive = support for trait presence, negative = support for trait absence. Interpretation of log-Bayes factors is based on Kass and Raftery’s (1995) modification of Jeffreys (1961, Theory of probability. 3rd edn. Oxford Univ. Press, Oxford, UK.): 0 to 2, barely worth mentioning; 2 to 6, positive; 6 to 10, strong; >10, very strong. Boldface numbers following species names indicate Volvox developmental programs following Desnitski (1995).

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Volvox 2015: development

Replica of Antonie van Leeuwenhoek's microscope.

Ray Goldstein‘s working (!) replica of Antonie van Leeuwenhoek’s microscope.

At the start of the Development session, I asked for a show of hands of people who self-identify as developmental biologists. About four went up. That’s not quite fair, since there’s some ambiguity in the question (primarily? exclusively?), but my point was that what all of us who are interested in the evolution of multicellularity study is the evolution of development. In fact, it might fairly be said that the origin of multicellularity is the origin of development.

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Friday Golden Fleece: Wildflowers in a Ghost Town

Colorado wildflowers

Colorado wildflowers. Photo by Aeravi.

In response to the American Recovery and Reinvestment Act (a.k.a. the stimulus) Senators Tom Coburn and John McCain published a Stimulus Checkup in December, 2009. This pamphlet concludes that “…billions of dollars of stimulus funding have been wasted, mismanaged, or directed towards silly and shortsighted projects,” and, not surprisingly, many of the projects so identified are federally funded scientific studies. Number 35 in this list is an NSF grant to Dr. David Inouye and colleagues:

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