@user_missinn on Instagram: "The post showcases a serene video of translucent jellyfish drifting in water, captioned with a light-hearted nod to their brainless, thought-free existence refined over 500 million years. Fossil records confirm jellyfish emerged during the Cambrian period around 500 million years ago, making them one of Earth's oldest multicellular animals, with no central brain but a simple nerve net for sensory responses. Recent studies, including a 2023 paper in Current Biology, r