Pierrick Bourrat on levels, time, and fitness, part 1: zero fitness?

Pierrick Bourrat’s new paper in Philosophy and Theory in Biology criticizes aspects of the influential ‘export of fitness’ framework developed by Rick Michod and colleagues and extended by Samir Okasha (Bourrat, P. 2015. Levels, time and fitness in evolutionary transitions in individuality. Philos. Theory Biol., 7: e601. doi: 10.3998/ptb.6959004.0007.001). According to this view, an evolutionary transition in individuality, for example from unicellular to multicellular life, involves a transfer of fitness from the lower level units (e.g. cells) to the higher level unit (e.g. nascent multicellular organism). Fitness is defined as the product of viability and fecundity, and the emergence of a division of labor between reproductive (germ) and non-reproductive (somatic) units at the lower level exports fitness to the higher level. Full disclosure: Rick Michod was my Ph.D. co-advisor, and he has had a huge influence on my thinking about this topic.

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Friday Golden Fleece: Strike a Smile

This was a guest post by Gwendolyn Nix.

Why is Jesus smiling? The answer may surprise you.

Why is Jesus smiling? The answer may surprise you.

In a recent article, FierceRoller tackled the notorious Golden Fleece Awards and the Wastebook, two award projects created and given by United States Senators decrying research proposals they deem silly and wasteful.

Naturally, as scientists, we nurse a certain outrage towards those without scientific training (or the determination to fully read a scientific paper) who assert that certain studies are worthless. I don’t go around the House of Representatives telling the Speaker of the House how to do his job. I wouldn’t even go to MacDonald’s and tell the fry cook that I could make better fries without the gumption prove it. Because I am excited to put my money where my mouth is, I’m going to analyze the Golden Fleece Award given to Robert E. Kraut and Robert E. Johnston on their study of why bowlers smile.

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Who are you calling lower?

Weismann Fig. 62

Fig. 62 from Weismann, A. 1904. The Evolution Theory. London: Edward Arnold. Pandorina morum; after Pringsheim. I, A young colony, consisting of 16 cells. II, Another colony, whose cells have reproduced daughter-colonies; all the cells uniformly alike. III, A young Volvox-colony; sz, somatic cells; kz, germ-cells.

I needed to cite some information from August Weismann’s 1904 book The Evolution Theory1 yesterday, so I did something I rarely do anymore: walked over to the library and checked out a physical copy. The University of Montana library has a first edition, two-volume set of the translation by Arthur Thomson. I’m always interested to see how biologists thought about Volvox before people like Richard Starr, David Kirk, and Rüdiger Schmitt came on the scene. All of the quoted text is from pages 257-261 in Volume I.
Among the lower Algae there is a family, the Volvocinæ, in which the differentiation of the many-celled body on the principle of division of labour has just set in; in some genera it has been actually effected, though in the simplest way imaginable, and in others it has not yet begun.

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Volvox 2015: early registration deadline extended

Hey slackers,

If you procrastinated on registering for the Third International Volvox Meeting, you’ve been granted a reprieve: the early registration deadline has been extended to the end of May.  After that, it goes up by £50 (around $80). This has been a great meeting in the past, and this year promises to be even better. The conference kicks off with a collecting trip and includes sessions on life cycles, development, biophysics, evolution and ecology, genetics, phylogenetics and taxonomy, and genomics (program). At £250 for regular registration including accommodation (£180 for students and postdocs), this is a great deal. So if you can use an extra $80, go ahead and register before the end of May.

Here is a pdf version of the meeting poster.

Evolutionary Transitions to Multicellular Life published

Iñaki Ruiz-Trillo and Aurora Nedelcu have recently edited a new book on the evolution of multicellularity, Evolutionary Transitions to Multicellular Life.  The 22 chapters are divided into five sections: “Multicellularity in the Tree of Life,” “Model-Systems,” “Theoretical Approaches,” “Genomics Insights,” and “Molecular Mechanisms,” and the forward is written by Nicole King. Volvox  shows up in the chapters by Susan C. Sharpe, Laura Eme, Matthew W. Brown and Andrew Roger (“Timing the origins of multicellular eukaryotes through phylogenomics and relaxed molecular clock analyses”); by myself and Aurora Nedelcu (“Volvocine algae: from simple to complex multicellularity”); by Cristian A. Solari, Vanina J. Galzenati and John O. Kessler (“The evolutionary ecology of multicellularity: the volvocine green algae as a case study”); by John O. Kessler, Aurora M. Nedelcu, Cristian A. Solari and Deborah E. Shelton (“Cells acting as lenses: a possible role for light in the evolution of morphological asymmetry in the volvocine algae”); and by Daniel Lang and Stefan A. Rensing (“The evolution of transcriptional regulation in the Viridiplantae and its correlation with morphological complexity”).

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Friday Golden Fleece

Blue monkey, Cercopithecus mitas stuhlmanni

Blue monkey, Cercopithecus mitas stuhlmanni

Dating back to at least the 1970s, Washington politicians have a tradition of decrying scientific funding that they deem wasteful. From Senator William Proxmire’s Golden Fleece Award to Sarah Palin’s “fruit fly research in Paris, France” to Senator Tom Coburn‘s annual “Wastebook,” particular research projects that can be made to sound silly are singled out for ridicule. The politicians, of course, have every right to make these criticisms, but scientists often see them as unwelcome intrusions by elected officials who (almost always) lack the scientific background to understand the research they mock.
So how have the politicians done? Have the projects singled out for ridicule indeed been ridiculous wastes of taxpayer money? I (and hopefully some guest bloggers) will be taking a look at some of the criticized projects to understand just how insightful politicians are at identifying useless research.

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Congratulations to Maggie Boyd!

2015 UMCUR award winners with UM President Royce Engstrom.

2015 UMCUR award winners with UM President Royce Engstrom.

Undergraduate Maggie Boyd has been awarded the Life Sciences Poster Award in the University of Montana Conference for Undergraduate Research for her poster “Motility in Chlamydomonas reinhardtii.” This is kind of a big deal: only one poster award and one oral presentation award were bestowed in Life Sciences university-wide.

Maggie has also recently been awarded a Honerkamp-Smith Travel Grant to attend the Third International Volvox Meeting in Cambridge, U.K. this summer.

Pleodorina study featured on NAI website

My new paper in Evolutionary Ecology Research is currently featured on the NASA Astrobiology Institute website (“Algae Fitness and Multicellular Life“). This was the final chapter of my Ph.D. dissertation, and it describes an artificial selection experiment using Pleodorina starrii. The paper is co-authored by my Ph.D. advisor, Rick Michod, and two (then) undergraduates, Susma Ghimire and Conner Vinikoor.
Pleodorina starrii

A 32-celled colony of Pleodorina starrii with 12 somatic cells.

Pleodorina is considered “partially differentiated,” meaning that some of its cells are of the ancestral, undifferentiated type (like those of Eudorina) and some are differentiated as somatic cells. These somatic cells never grow much, and they never divide to form daughter colonies.

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Ann Gauger teaches us about Volvox, part 2

Last time, I criticized Ann Gauger’s Evolution News and Views article “A Simple Transition to Multicellularity — Not!” for asserting that the requirement for kinesins in Volvox inversion implied a requirement for novel genes in the evolution of multicellularity. In a similar vein, Dr. Gauger presents programmed cell death and sex as problems for this transition:
The somatic cells commit suicide by a process known as apoptosis — programmed cell death — that I wrote about here. This process involves a minimum of several novel genes as well.
Where does this assertion that programmed cell death in Volvox “involves a minimum of several novel genes” come from? Programmed cell death (PCD) occurs in many unicellular eukaryotes, including Chlamydomonas reinhardtii. Furthermore, two types of metacaspases, genes involved in PCD in many algae and plants, are found in both Chlamydomonas and Volvox.
Metacaspases

Partial alignment of representative type I and type II metacaspase predicted sequences from red algae (Porphyra yezoensis; Py), green algae (Chlamydomonas reinhardtii, Cr; Volvox carteri, Vc), vascular plants (Arabidopsis thaliana; At), excavates (Trypanosoma cruzi, Tc; Leishmania braziliensis, Lb), diatoms (Thalassiosira pseudonana, Tp; Phaeodactylum tricornutum, Pt), haptophytes (Emiliania huxleyi; Eh), pelagophytes (Auroecoccus anaphagefferens; Aa), yeasts (Schizosaccharomyces pombe, Sp; Saccharomyces cerevisiae, Sc) showing the conservation of the cysteine-histidine dyad and the insertion characteristic of plant type II metacaspases. From Nedelcu, A.M. 2009. Comparative genomics of phylogenetically diverse unicellular eukaryotes provide new insights into the genetic basis for the evolution of the programmed cell death machinery. J. Mol. Evol., 68: 256–268. doi 10.1007/s00239-009-9201-1.

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