Religions around the world have different narratives about the creation of human beings, in which it is said that a powerful god creates men and women with a fully developed brain. However, placozoans, tiny creatures that float in marine water, reveal a different reality. Placozoans are animals smaller than a millimeter with no organs or brains, but they have the astonishing ability to coordinate and attack their prey in groups.

A team of scientists has studied placozoans and discovered that the origins of neurons, which are responsible for human thought, can be found in their cells. Despite having only 50,000 cells, placozoans are able to coordinate because some of their cells can send chemical messages similar to the neurotransmitters in our neurons.

This discovery supports the hypothesis of a chemical brain proposed by biologist Gáspár Jékely from the University of Heidelberg. According to this hypothesis, nervous systems first evolved as a group of cells that communicated chemically, before developing the specialized structures of human neurons.

The origin of neurons still remains a mystery, but placozoans provide clues about how single-celled organisms came together and created more complex multicellular beings. Although placozoans are the simplest animals on the planet, studying them is essential for understanding the evolution of cells and nervous systems.


– Placozoans: Tiny animal creatures smaller than a millimeter with no organs or brains.
– Neurons: Cells in the nervous system responsible for transmitting nerve impulses.
– Neurotransmitters: Chemical molecules that transmit signals between neurons.
– Chemical brain: Hypothesis proposed by Gáspár Jékely suggesting that nervous systems first evolved as cells that communicated chemically.

Source: El País