Last time, I wrote about Julian Huxley’s 1912 book, The Individual in the Animal Kingdom, and his use of the volvocine algae as an example. I liked most of what he had to say, though I took issue with his assertion that
…all the other members of the family except Volvox…are colonies and nothing more—their members have united together because of certain benefits resulting from mere aggregation, but are not in any way interdependent, so that the wholes are scarcely more than the sum of their parts.
This is, of course, a matter of how we define a multicellular organism, but I think any definition that excludes, for example, Eudorina, is not a very useful one.
This time, I’ll look at the rest of what Huxley had to say about the volvocine algae, most of which is about Volvox:
Julian Huxley was one of the biologists responsible for the merging of Mendelian genetics and Darwinian evolution in the early 20th century, the modern synthesis. His most influential work was Evolution: The Modern Synthesis, published in 1942. Thirty years earlier, though, he published a book on biological individuality, The Individual in the Animal Kingdom. Thankfully, the copyright on this book has expired, so it is now part of the public domain, and a scanned version is available for free in pdf and epub versions from Google.
I’m set up to receive alerts when a few Wikipedia pages update, and I noticed an unusual amount of activity on the Volvox page. Turns out someone has been vandalizing the article. At one point, the first line read
”Volvoxiousmaximous”, discovered by Paul Hirn in 1869, is a polyphyletic blue jeans in the volvocine rainbow algae clade…
Alexey Desnitskiy from Saint Petersburg State University has published a new review of sexual development in the genus Volvox in the International Journal of Plant Reproductive Biology.
The article includes an up-to-date review of Professor Desnitskiy’s own work describing four developmental “programs” in the various species of Volvox:
The website for the Volvox 2017 conference is up at www.volvox2017.org. Registration isn’t open yet, but there’s some information about the venue, the Donald Danforth Plant Science Center in St. Louis. The meeting is set for August 16-19, 2017.
The goal of the International Volvox Conference is to bring together international scientists working with Volvox and its relatives (aka Volvocales or volvocine algae). We cordially invite experimentalists and theorists interested in these fascinating organisms.
I’ll keep you posted!
The following guest post was kindly provided by Dr. Kimberly Chen. I have edited only for formatting.
MicroRNAs (miRNAs) are a class of non-coding small RNAs that regulate numerous developmental processes in plants and animals and are generally associated with the evolution of multicellularity and cellular differentiation. They are processed from long hairpin precursors to mature forms and subsequently loaded into a multi-protein complex, of which the Argonaute (AGO) family protein is the core component. The small RNAs then guide the protein complex to recognize complementary mRNA transcripts and conduct post-transcriptional gene silencing.
Hisayoshi Nozaki and colleagues have just described some Volvox samples from two lakes and a pond in Japan.
The newly collected strains have a lot in common with another recently described species, Volvox ferrisii, but there are some important differences as well:
…it could be clearly distinguished from all previously described monoecious species of Volvox sect. Volvox by its small number of eggs or zygotes (5–25) in sexual spheroids, with short acute spines (up to 3 μm long) on the zygote walls and elongated anterior somatic cells in asexual spheroids.
In spite of these differences, Nozaki and colleagues stop short of calling the newly collected strains a new species. Why?
The Fourth International Volvox Conference will be held in St. Louis, Missouri August 16-19, 2017, with Jim Umen organizing.
Starting in 2011, we have had a Volvox meeting every other year (every year there’s not a Chlamydomonas meeting, that is). The first meeting was at Biosphere 2 outside of Tucson, Arizona, the second at the University of New Brunswick, and the third at Cambridge University.
You don’t have to study Volvox to join us; the meeting is open to anyone with an interest in the evolution of multicellularity (last year’s invited speaker was Professor Pauline Schapp, who studies cellular slime molds).