Having once been threatened with a SLAPP suit (which is a lot less than some of my better-known Freethought Blogs colleagues have had to deal with), I appreciate the hell out of this. Contains swears. Lots and lots of swears. And rude gestures.
For once, the YouTube comments are pretty great, too.
Figure 4 from Haas et al. 2018. Average shapes of Volvox globator embryos for 10 stages of inversion (red lines), obtained from N = 22 overlaid and scaled embryo halves (lines in shades of blue on the left) and corresponding standard deviation shapes (shaded areas on the right).
One of my search alerts turned up a blog post about Volvox inversion, “Upside Down and Inside Out: Inversion in Volvox.” The author wasn’t identified at the top, but by the third paragraph it was clear that the post was written by someone with a deep familiarity with the subject:
In order to be able to swim, the colony must therefore turn itself inside out through a hole at the top of the cell sheet. This process is called inversion, and proceeds in different ways (type-A and type-B inversion) in different species. (It is not clear why Volvox evolved to have its flagella on the inside after cell division: the closely related alga Astrephomene divides into spherical colonies without the need for inversion.
Suppose I were to pick some group of people, Buddhists, for example, or millennials, or Australians, and start writing nasty things about them. Suppose I said that members of this group, not some of them but all of them, were stupid, unethical, ignorant, intellectually and morally depraved, and incapable of either knowing right from wrong or believing in love. Suppose I argued that these traits were not incidental, not demographic trends, but necessary outcomes of membership in the group, in other words that belonging to the group causes them (just in case this isn’t 100% clear, I don’t believe any of these things about any of these groups).
If I wrote all that, do you think it would be fair to say that I was trying to dehumanize members of the group I was writing about? I certainly do. I sincerely hope that you would stop reading anything I wrote, block me on social media, and bring my hate speech to PZ Myers’ attention so that I’d get kicked off of Freethought Blogs.
So I find it ironic that some of the people who are saying those things are also accusing the members of the group they’re saying it about of dehumanizing others.
Check out Martyn Kelly’s blog post about Volvox from a pond in England:
The annual Algal Training Course in Durham always has a field trip out to Cassop Pond, a small pond at the foot of the Permian Limestone escarpment in County Durham that has featured in a few of my posts over the years (see “A return to Cassop”). This year, the group came back with some samples from the pond’s margins bearing a suspension of green dots just visible to the naked eye which, when examined under the microscope, turned out to be the colonial green alga Volvox aureus.
There’s more, including some lovely micrographs, at https://microscopesandmonsters.wordpress.com/2019/07/17/the-intricate-life-of-a-colonial-alga/.
Figure 1A from Dayel et al. 2011. Spherical colony of Salpingoeca rosetta. Scale bar = 5 μm.
The closest (known) living relatives of animals are a group of unicellular or colonial filter-feeders known as choanoflagellates. Much of what we know about the evolution of multicellularity in animals comes from comparisons with choanoflagellates. For example, many of the gene families involved in multicellular development in animals, and previously thought to be unique to animals, have turned out to be present in choanoflagellates as well, suggesting that these gene families were present in animal ancestors before they evolved multicellularity. Some multicellular choanoflagellates have even been shown to have differentiated cell types (Laundon et al. 2019):