Author: vpochic
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A tree of protists
Here’s a drawing of a phylogenetic tree of eukaryotes where I represented some lineages of protists. Major clades are indicated by the coloured clouds. The tree is based on the one shown in figure 1 of Keeling (2013), but I omitted some branches on purpose so it isn’t too crowded. Lineages containing phytoplanktonic organisms have…
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Shades of blue
A short collection of nice ocean colour satellite images. All three were captured by the MSI sensor onboard the Sentinel-2 Earth observation satellite from the European Space Agency. These are ‘true colour’ RGB images based on reflectance data in 3 spectral bands: Red: Band 4 (665 nm), Green: Band 3 (560 nm) and Blue: Band…
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Visualising 16 years of phytoplankton community dynamics
My esteemed colleague Jean-Yves Dias recently published an article on phytoplankton communities in French coastal waters. We worked on it together with 2 other co-authors, and it’s the result of more than 2 years of hard work (especially on Jean-Yves’ part) so I’m quite proud to advertise it on the blog! The paper is (objectively…
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Heat and run: temperature at the Western States 100
Tomorrow (Saturday 27th of June) is the start of the 53rd edition of the Western States Endurance Run (WSER, or Western States for short), a legendary long-distance race taking place in the Sierra Nevada mountains of California. I like marine microbes, but I also really like running, and I’m quite excited for this year’s edition…
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Proust, les protozoaires et les confitures
Un joli passage de Proust (enfin, une phrase…), qui mentionne les protozoaires, entre autres choses. C’étaient de ces chambres de province qui – de même qu’en certains pays des parties entières de l’air ou de la mer sont illuminées ou parfumées par des myriades de protozoaires que nous ne voyons pas – nous enchantent des…
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An unseen organism and a hypothesis about the origin of viruses
What is a parasite? A definition that often comes up is this one: Parasites, in a phrase, are predators that eat prey in units of less than one. Edward O. Wilson, The Meaning of Human Existence (2014) The sentence is funny, but in my opinion it’s not really a good definition. First, what about “units…
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A vivid, 273-year-old description of a famous ciliate
(And another funny description of a creature that, probably, doesn’t exist.) Both I discovered in the excellent A manual of the Infusoria, by English biologist William Saville-Kent, published in 1882. “Infusoria” was a term used at the time to encompass virtually all protozoans (that is, anything flagellate, ciliate or “tentaculiferous”) observed in water. From what…
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Frog feet
A few days ago, a colleague of mine asked me how biologists decide which microalga is their favourite. (She’s a physicist, I guess these strange people have favourite equations or something.) That got me thinking. What’s the coolest microbial species? Of course, the answer will depend on who you ask, because the notion of “cool”…
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Prokaryote/Eukaryote
Where we explore the relatively young history of a fundamental divide in the tree of Life. A deliberately short history of systematics Systematics is the science of classifying life forms. As with almost anything in science, the first traceable attempts at classifying life date back to Aristotle. In his treaty The History of Animals (4th…
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Dead gods
Following is an extract from André Lwoff‘s lecture “The Concept of Virus“, given before the Society for General Microbiology on April 15th, 1957. I attempted to translate it into French just after. If you want to read the entire lecture (which I can only recommend), you can access it here : The Concept of Virus…
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