New Miscellany 2: Animal intelligence in phytoplankton (General)

by David Turell , Tuesday, June 17, 2025, 18:46 (10 days ago) @ David Turell

They sense environmental changes and adapt:

https://phys.org/news/2025-06-stocking-snacks-phytoplankton-future.html?utm_source=nwle...

"Single-cell plants called phytoplankton have a surprising way of remembering conditions in the past to help jump-start their growth in the future, but no one is sure exactly how they do this.

"Researchers,... detail their mechanistic theory of how this phenomenon, known as phenotypic memory, works in phytoplankton in their paper published in PNAS.

"Though small, phytoplankton are hugely important because they make about as much oxygen globally as all of the oxygen-producers we usually think of like trees and grasses, says Kremer.

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"'We grew the phytoplankton in test tubes at different temperatures and then manipulated their past and present conditions by moving the test tubes to different places along that block," Kremer explains. "Then we measure their growth by looking at how much biomass accumulated over time."

"In the paper, lead author Anderson detailed the development of a mathematical theory to describe the mechanism of phenotypic memory. He also compared the experimental data to the theoretical model and Kremer says they were excited by how closely the relatively simple model captured the data they collected in the lab.

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"They found that the ability to store nutrients for future biomass production is integral and determines how quickly phytoplankton can grow.

"'The easiest analogy we've come up with for this is, if you think about a phytoplankton growing in water that's fairly cold, its ability to grow is fundamentally limited by temperature and its cellular machinery for growth," says Kremer.

"'But, for a lot of these phytoplankton, while they're not growing very quickly, they are still able to take up and store extra nutrients from their environment. It's like stocking up on snacks and then, if their environment warms up, the temperature is no longer limiting how quickly they can grow, and they've got a ton of snacks, so it supercharges their growth for a period of time."

"After faster growth in warmer conditions, the phytoplankton's growth eventually slows down. Once temperatures drop again, their growth also slows since they have run out of snacks.

"'In some instances, we observe phytoplankton being able to perform Herculean feats for a few days. Even though brief, such instances may be matters of life or death for these organisms. For example, our results indicate phenotypic memory can mitigate the downsides of high temperature stress if heat waves are initiated from cool starting conditions," says Fey.

"'This nutrient storage or how many snacks they have on hand is a way of carrying over past information about their environmental exposure that then influences how they're behaving at any given moment in time," says Kremer.

"To further explore this mechanism, the next steps include measuring the quantities of different nutrients stored over time, says Kremer.

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"'We think it's likely to be a general mechanism for different phytoplankton, but we'd like to expand how this data is collected. I also think the theory suggests many different things we can now look for in terms of what is happening physiologically within these cells to figure out if it's the storage of nitrogen or phosphorus, or some other nutrient that drives these patterns."

Comment: once again in a single cell, is it DNA instructions handling the problems or is something intelligent occurring?