Some travel awards will be granted to students and postdocs attending the Fourth International Volvox Conference (Volvox 2017) in St. Louis. Applications are due July 1, 2017. If you are planning to attend the meeting as a student or postdoc, you really should apply.
Dr. David Kirk, Professor Emeritus at Washington University in St. Louis.
I just found out from Jim Umen, who’s organizing the Fourth International Volvox Conference, that David Kirk is planning to attend. This is great news; we’ve been wanting Dr. Kirk to come since the first meeting in 2011, but it hasn’t previously worked out.
Discounted registration for the Volvox 2017 meeting has been extended to June 16th. This is a pretty good deal as scientific meetings go: $550 for faculty includes registration, most meals, and a shared room. Registration for postdocs and students is $100 less, and there are travel grants available. If you’ve been debating whether or not to go, it’s decision time: prices will go up $100 after the 16th.
Just a reminder, abstracts for the Fourth International Volvox Conference (Volvox 2017) in St. Louis are due next Friday, June 16, 2017.
Eudorina elegans, from Ehrenberg 1832.
Eudorina elegans was described by the German biologist Christian Gottfried Ehrenberg in his Lectures at the Academy of Sciences in Berlin in the years 1830–1836 (Vorträge in der Akademie der Wissenschaften zu Berlin im Jahre 1830-1836). With the help of Google Translate, here’s what he had to say about it (page 17):
I have also found an eye-shaped form in the family of the epigones, or of the mucous, intestinal infusoria, which have a hairy body. This form of infusoria is also undefined, but it is confused by me, and probably by all previous observers, with Pandorina Morum (Volvox Morum Müller); Less accurate observers also thought they were probably Volvox Globator. I found them in the basin of the animal garden in the spring of this year between conferences. It is quite consistent with the same form, as I see from my drawing made in the Ural, that the animal which I, as Pandorina Morum, from Kyschtym, have doubtless listed in my list of the Russian Infusoria, and I am of the opinion that I had at that time only overlooked the unsuspected eye. The body consists of a gelatinous, globule-shaped sphere, in which a certain number of spherical, green-colored animals are enclosed, each showing a beautiful red, round but small eye, and a simple, long, whirling, or supporting eyelash through the water. The whirling is seen very clearly as soon as a fine, turbid substance is added to the water. To this animal, which is one of the most beautiful infusoria, I have given the generic name Eudorina, in consideration of the closely related eyeless genus Pandorina. The only known species I have called Eudorina argus (beautiful green eye ball).
Hiroyuki Sekimoto from Japan Women’s University has published a review of sexual reproduction in the volvocine algae and in the Charophyte Closterium in the Journal of Plant Research. In addition to a brief description of the Chlamydomonas sexual cycle, it includes a succinct review of the genetics of sex and sex determination. Unfortunately, the article is paywalled, and my inquiry to the author has so far gone unanswered.
Figure 1 from Sekimoto 2017. The life cycle of Chlamydomonas reinhardtii. Vegetative cells (V) differentiate into mt+ and mt− gametes (G) during nitrogen starvation (−N). Mating types are restricted by mating-type loci (+ and −). When gametes are mixed, the plus and minus agglutinin molecules on their flagellar surfaces adhere to each other, and this adhesion results in increased intracellular cAMP levels. The signal triggers gamete cell wall release and mating-structure activation. Cells then fuse to form binucleate quadriflagellated cells. Zygotes with thick cell walls germinate in response to light and nitrogen supplementation, and undergo meiosis to release four haploid vegetative cells.
I track the #Volvox hashtag on Twitter, which is how I find out about a lot of the off-label uses of the name Volvox, like DJ Volvox, Volvox the ship, and Volvox the art gallery. Every now and then, it even turns up something related to Volvox the little rolling algae. The other day, @QuintaSwinger tweeted the following video with #Volvox:
The Twitter handle is about just what you think it is; apparently volvocine sex puts someone in mind of polyamory. I suppose I can see that: when a sperm packet enters a colony, it gets busy with all the ova. The video was uploaded to YouTube by Dr. Donald Ott from the University of Akron.
I think the algae in the video are not actually Volvox, though. Certainly the still photo at the beginning is Volvox. Probably not section Volvox (too few cells), and probably not Developmental Program 2 (germ cells too small in the one on the lower right). If I had to guess, I’d say V. aureus, but that’s largely a Bayesian bet because they’re so common. Maybe Alexey Desnitskiy or Hisayoshi Nozaki can comment.
The colonies in the video, though, look more like Pleodorina to me. Not P. sphaerica, since the somatic cells are all in the front, but without more information I can’t narrow it down more than that.
Figure 5 from Butterfield 1990. Bangiomorpha pubescens.
In my post on Bangiomorpha, I said
…Bangiomorpha was probably a red alga. This conclusion seems to be accepted by most everyone in the field. In fact, I don’t know of any dissenters, and that kind of consensus is rare for fossils this old.
I guess I didn’t look hard enough, because reader not the FTB Stewart commented
Cavalier-Smith dissents (dissented?) from the consensus
https://books.google.co.uk/books?id=lE6r5q5op94C&pg=PA63&lpg=PA63#v=onepage&q&f=false
A project started five years ago has finally borne fruit. In May, 2012 I joined a group of philosophers, historians, and biologists in Philadelphia for the Cain Conference “E pluribus unum: Bringing biological parts and wholes into historical and philosophical perspective.” The meeting was organized by Lynn Nyhart and Scott Lidgard, with the goal
…to pursue the question: How can historians, philosophers, and biologists help each other to understand part-whole relationships in biology, both today and in the past?
When I was putting together my post about Rafatazmia, the 1.6 billion-year-old fossil tentatively interpreted as a red alga, I searched Fierce Roller to see what I had written about Bangiomorpha, the previous record-holder for the oldest red algal fossil. I was surprised to find that I never have published anything about Bangiomorpha. This is a serious oversight!
Bangiomorpha was described by Nick Butterfield back in 1990, from a series of fossils collected on Somerset Island in Nunavut, the northernmost territory in Canada: