Levels of selection in biofilms: Ellen Clarke on individuality

Pseudomonas biofilm. From Spiers et al. 2013.

Pseudomonas biofilm. From Spiers et al. 2013.

The question of what constitutes a biological individual is intimately entangled with questions about levels of selection. Many authors implicitly or explicitly treat individuals as units of evolution or some variation on this theme. A recent appreciation for the complexity of bacterial biofilms has led to comparisons with multicellular organisms. A recent paper by Ellen Clarke bucks this trend by claiming that multispecies biofilms are not evolutionary individuals.

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Chlamy 2016 registration open

Screenshot 2016-03-17 07.18.34

Registration and abstract submission for the 17th International Conference on the Cell and Molecular Biology of Chlamydomonas (Chlamy 2016) are now open. The deadline for abstract submission is April 11th. The meeting will be at the Kyoto International Conference Center June 26-July 1. This year’s program includes a session on “Evolution, Chlamydomonadales / Volvocales.”

The flip side of the Galileo Gambit: Denyse O’Leary on multicellularity

Figure 7 from Anderson et al. 2016. Evolution of GKPID’s new function by unveiling a latent protein-binding site. (A) The binding surface for Pins in GKPIDs is derived from the GMP-binding surface of gk enzymes. Homology models of Anc-gkdup (left) and Anc-GK1PID (right) are shown as white surface, with all side chains that contact either GMP or Pins as yellow sticks. Pink sticks show GMP; green ribbon shows Pins backbone, with the side chains of all Pins residues that contact the GK protein shown as sticks. The phosphate group on GMP and on Pins residue 436 are shown as orange and red sticks. Black dotted lines, protein-ligand hydrogen bonds. In the AncGK1PID structure , substitutions at sites in the binding interface are shaded red, including key substitution s36P. The binding modes of extant gk enzymes and GKPIDs are similar and support the same conclusions (see Figure 7—figure supplement 1). (B) The structure of the hinge and GMP/Pins-binding lobes is conserved between the Pins-bound GKPID (blue, rat Dlg, 3UAT), the apo-gk enzyme (brown, S. cerevisiae guanylate kinase 1EX6), and the apo-gk-s36P mutant (gray, 4F4J), all in the open conformation.

Figure 7 from Anderson et al. 2016. Evolution of GKPID’s new function by unveiling a latent protein-binding site. (A) The binding surface for Pins in GKPIDs is derived from the GMP-binding surface of gk enzymes. Homology models of Anc-gkdup (left) and Anc-GK1PID (right) are shown as white surface, with all side chains that contact either GMP or Pins as yellow sticks. In the AncGK1PID structure , substitutions at sites in the binding interface are shaded red, including key substitution s36P. (B) The structure of the hinge and GMP/Pins-binding lobes is conserved between the Pins-bound GKPID (blue, rat Dlg, 3UAT), the apo-gk enzyme (brown, S. cerevisiae guanylate kinase 1EX6), and the apo-gk-s36P mutant (gray, 4F4J), all in the open conformation.

Cdesign proponentsists really don’t seem to like research on the evolution of multicellularity. Pretty much any time real scientists learn something new about the origins of multicellularity, writers on intelligent design blogs Evolution News & Views and Uncommon Descent feel compelled to tell us why it’s wrong (for example, here, here, here, here, here, here, here, here, here, here, here, here, and here).

So I shouldn’t be surprised that Denyse O’Leary has weighed in on the latest work out of Ken Prehoda’s lab, in which Prehoda and colleagues identified a mutation crucial for forming and maintaining tissues in animals. Worse, from O’Leary’s point of view, the article describes the evolution of a new protein function, which is anathema to intelligent design thinkers. To say this post is badly argued is overly generous; it’s absolutely devoid of any substantive argument.

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Moving without limbs! Linnaeus on Volvox

 

Linnaeus - 1758

In ancient times, when dusky seaside sparrows still roamed the Earth, I took two years of high school Latin. My Latin name was Matteus (we were all required to call each other and Mrs. Knowles by our Latin names); my Latin motto was “carpe diem.” That’s about how much I remember. Thankfully, in these modern times, we have Google Translate*. If you remember more Latin than I do, please feel free to correct my translations in the comments.

Linnaeus gave Van Leeuwehoek’s “great round particles” the name Volvox in his Systema Naturae. Linnaeus lists two species of “Volvox“, V. globator and V. chaos. “Volvox chaos” is an amoeba now known as Chaos sp. (though there is some confusion about its exact identity). Although AlgaeBase lists V. chaos as a valid taxon, Leidy (1879, pp. 30-35) reviews the synonymy of Chaos, and it is clearly an amoeba, not an alga.

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The Discovery Institute still doesn’t understand free speech

The Discovery Institute has a persecution complex. They have a hard time distinguishing between rejection and mockery of their silly ideas and violation of their right to free speech. They’ve created a ‘Censor of the Year’ award to protest their treatment. The previous winners are noted free speech opponents Jerry Coyne and Neil deGrasse Tyson.

For the past month, they Institute has been in an absolute tizzy over the decision of the United Methodist Church’s decision to exclude (‘ban‘) them from its General Conference coming up in May. Because they don’t understand that free speech doesn’t obligate others to provide a platform, they think this decision amounts to ‘intolerance‘ and ‘censorship‘.

Censorship

Persecution complex? Image from an Evolution News & Views post on UMC.

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Where’s the revolution? More from Drs. Weil & Chopra

WeilChopra

Being on Andrew Weil’s mailing list is entertaining (see “Journey into bullshit“). His latest mailing advertises his upcoming webinar with Deepak Chopra. The website for this event (on chopra.com) starts off

Are Your Genes Your Destiny?

Until very recently, scientists would have said yes.

In fact, it was widely accepted that the genes we inherited at birth controlled everything – from our personalities to our health to our longevity. So if you were unlucky enough to inherit the gene for cancer or heart disease, you were expected – no matter who you were or how you lived – to develop that disease.

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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 T-shirts

Volvox t-shirt, women's

If you need more Volvox-themed clothing (and who doesn’t?), by ribosoma biological designs has you covered. They’re available in long-sleeved or short-sleeved. I don’t know how long these will take to ship from Spain, but if you didn’t get one of the super-cool shirts from the Volvox meeting, now’s your chance!

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