ZeFrank on slime molds

February 2, 2023 • 1:45 pm

I can’t even give you a position of slime molds on the tree of life because their constituents are so diverse (a few of my science friends work on them). This is from Wikipedia:

Slime mold or slime mould is an informal name given to several kinds of unrelated eukaryotic organisms with a life cycle that includes a free-living single-celled stage and the formation of spores. Spores are often produced in macroscopic multicellular or multinucleate fruiting bodies which may be formed through aggregation or fusion. Slime molds were formerly classified as fungi but are no longer considered part of that kingdom. Although not forming a single monophyletic clade, they are grouped within the paraphyletic group Protista.

More than 900 species of slime mold occur globally. Their common name refers to part of some of these organisms’ life cycles where they can appear as gelatinous “slime”. This is mostly seen with the Myxogastria, which are the only macroscopic slime molds. Most slime molds are smaller than a few centimetres, but some species may reach sizes up to several square metres and masses up to 20 kilograms.

They feed on microorganisms that live in any type of dead plant material. They contribute to the decomposition of dead vegetation, and feed on bacteria and fungi. For this reason, slime molds are usually found in soil, lawns, and on the forest floor, commonly on deciduous logs. In tropical areas they are also common on inflorescences and fruits, and in aerial situations (e.g., in the canopy of trees). In urban areas, they are found on mulch or in the leaf mold in rain gutters, and also grow in air conditioners, especially when the drain is blocked.

ZeFrank’s videos are getting more and more biological and more and more engaging. This new one has some spectacular video, for these creatures have some bizarre behaviors. (There’s an ad from 5:33 to 6:45.) These things can even learn mazes and teach humans how to make efficient transportation routes!

If you don’t think biology is fascinating after watching this, you need to polish up your sense of wonder.

15 thoughts on “ZeFrank on slime molds

  1. Very smart creatures. Smarter than d*gs, at least along some axes of brilliance.

    We saw slime mold a lot when we lived on Orcas Island. Hiking through the wet forest, they were frequent occupants of rotting logs and other slimy things. My wife actually has a favorite slime mold, the Dog Vomit slime mold. Learn how to grow and care for it here: https://www.thespruce.com/identifying-and-controlling-dog-vomit-fungus-2539510.

    Is it a non-sentient garden ornament? Or is it a pet? It’s your call.

    1. Controlling slime mold? How sad that people feel the need to remove it, or that the article even included tips to do so. Yea, they talked about “care”, and pointed out that it is harmless, so why not leave it at that?

      I recently came across an online article that talked about how to kill mosses, lichens, and algae that were living on your trees. Why?! Because it might be…(gasp) unsightly! If a person is so terrified by the tangled bank of the natural world, they should stick to high rise apartments and never go outside, but leave the beauty of the outdoors for the rest of us.

        1. I’m guessing that it’s a combination of suburban sensibilities and concern about property values, though I don’t know in what proportion.

  2. Also interesting are cellular slime molds like Dictyostelium, where we see a large number of individuals in a population apparently “choosing” to be non-reproductive.

    1. Fun fact: Dictyostelium discoideum was the first slime mould to have its genome sequenced, back in the early 2000s. It was chosen because its lifecycle appears to bridge the gap between single-celled and multi-celled organisms, and the hope was that its genome would reveal clues about how life on Earth made the transition to multi-cellularity about 600 million years ago.

      Reference: Eichinger, L., et al., (2005) The genome of the social amoeba Dictyostelium discoideum, Nature, 435, 43

      (Declaration of interest: I was part of the team at the Wellcome Sanger Institute which participated in this project.)

  3. Ze Frank does for biology what Joe Blogs does for economics: makes it interesting. His delivery is also very engaging. I wish I had had a biology teacher like him. (Does anyone know Joe Blogs” real name?)

  4. If you don’t think biology is fascinating after watching this, you need to polish up your sense of wonder.

    Or, as Richard Dawkins put it: The Magic of Reality.

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