A Journal piece points to the flatworm as an example:
She offers the flatworm (Bedford’s flatworm, above right) as an example of intelligence without apparent equipment. This type of worm is flat because it lacks a well-developed respiratory and circulatory system. Otherwise, its cells communicate conventionally, using electrical signals — but with some dramatic results:
“Cut one into a hundred pieces and each piece will regenerate into a perfect new worm. (A slime mold-flatworm alliance against the humans would make a great horror movie). But how do the cells in the severed flatworm fragment know how to grow into a head and a tail? …
… In experiments that would make Dr. Frankenstein proud, the researchers altered those electrical signals to produce a worm that consistently regenerates with two heads, or even one that grows the head of another related species of flatworm. Alison Gopnik, “How can life forms show intelligence with no brain?” at Wall Street Journal”
A reasonable conclusion is that there is indeed intelligence involved but it isn’t in the individual flatworm. It is rather implicit in the origin and development of the flatworm. Thus the individual worm doesn’t think and doesn’t need to.– Mind Matters News
See also: Life forms that seem to think without brains:
How can life forms show intelligence with no brain? A Wall Street Journal piece points to the flatworm as an example. “Basal cognition” research explores the evidence for intelligence that does not depend on neurons and synapses.
Is a brain really needed for thinking? The “blob,” now on display at the Paris Zoo, forces the question.
Is an amoeba smarter than your computer? Hype aside, the microbe’s math skills ace the Traveling Salesman problem and may help with cybersecurity
Even bacteria are purpose-driven. The recent finding that bacteria can make individual decisions may help design better antibiotics.
and
Can plants be as smart as animals? Seeking to thrive and grow, plants communicate extensively, without a mind or a brain
Apparently, “basal cognition” research now explores the evidence for intelligence that does not depend on neurons and synapses.