Roundworms can share “memories”
Even some of the simplest lifeforms on earth have a rudimentary version of memory, such as the roundworm Caenorhabditis elegans.
Studies have found C. elegans possess the ability to “remember” harmful bacteria they’ve encountered in the past. In one particular case with P. aeruginosa bacteria, the encounter leaves behind a trace of bacterial RNA that induces a change in the worms’ germ line reproductive cells, allowing them to pass on knowledge of the threat to several generations of their progeny. What’s more, a 2021 study found that the bad memory of P. aeruginosa can be even shared horizontally with unrelated C. elegans worms, though it requires crushing up the worms and feeding them to their friends. So it’s not the easiest lesson ever learned.
