Well before I start collecting coats, keys or shoes, my dog always knows when we’re about to leave. By picking up on subtle cues, he anticipates our next movements, reminding me he’s smarter than often shows.

But anticipation isn’t always about the brains. Our new research reveals even an animal with no brain at all can anticipate what’s coming next.

The metamorphosis of the sea sponge

Sea sponges are one of our most distant animal relatives, lacking all the familiar sensory apparatus. They have no brain, no nerves and no neurons. Being not much more than well-organised collections of specialised cells, they’re pretty much as simple as animal life gets.

And yet, sea sponges carry out a wildly complicated process much like a backwards version of a caterpillar’s transformation, from squidgy grub to free-flying bug. Starting out as free-swimming larvae, about half the size of a chia seed, they transfigure themselves into shapeless, spongy lumps, cemented in place.

My colleagues and I have researched this miraculous metamorphosis for years. We have discovered that environmental cues play a very important........

© The Conversation