Many thanks to @ettema.bsky.social, @anja1.bsky.social, and Rick Cavicchioli for encouraging me to put this article together and for all the advice that helped along the way.

This is a great example of a situation where a behaviour appears antagonistic but in the ecological context in which the behaviour evolved it benefits both organisms compared to the alternative. It reinforces to me how important that context is when we interpret results from laboratory experiments.

However, more aggressive behaviour would likely allow the symbiont to more rapidly accumulate nutrients, increasing its ability to persist through the low nutrient periods.

In contrast, if the symbiont regulates behaviour as a function of nutrient availability or host proliferation both organisms can persist. Importantly, rate of host lysis under these conditions does not impact the persistence of either species, only population sizes.

The short version is that interactions similar to other DPANN, where the symbiont is constantly attached to the host, are unstable in ecosystems where nutrient availability approaches zero for extended periods. Populations of both organisms collapse eventually.

Congrats Dani! That's awesome news!

Many thanks to my co-authors @ndombrowski.bsky.social, @luisvalentin.bsky.social, @greening.bsky.social, @tweethinking.bsky.social, and @anja1.bsky.social!