The Evolution of a Head Has Been Traced Back Surprisingly Far Back Our Ancestral Line

What is going on in a head? There is new research that says a little bit of our ancestors tails.

In the early days of multicellular life on Earth, animals had no brains or spines. They only had a network of cells. Over the course of millions of years, the system became concentrated on one end. But how?

Sea squirts, or tunicates, are the closest living relatives of animals, and they don't have a true head.

The central nervous system of these animals is made up of clumps of neurons in the anterior and anterior parts of their body. Their cerebrum is easier to make out than tadpoles.

Tunicates are like an evolutionary prototype for animals.

The tadpole has a green tail. The University of Innsbruck.

It is a contentious area of research for evolutionary scientists. Evidence has recently been found to support their ideas.

Hmx genes, which are related to the genes that are related to clumps of neurons in a lamprey's head, were found by their research.

Lampreys are considered living fossils because they have been around for so long. Some of the first animals are the marine animals.

The jump from tunicate life to lamprey life was a big one, but the Hmx gene seems to have made it across the divide. The effect is different among animals.

The Hmx genes of a lamprey were found to help drive the expression of bipolar tail neurons.

The same genes helped drive the expression of sensory neurons in lampreys.

The function of Hmx genes in lampreys and tunicates suggests they have a common evolutionary origin and may have played a role in the centralization of the nervous system.

Hmx has been shown to be a central gene that has been conserved across evolution, according tozoologist Alessandro Pennati from the University of Innsbruck.

It has retained its original function and structure and was probably found in the common ancestor of vertebrates and tunicates.

The findings suggest that the brains of animals may have been recycled from their ancestors millions of years ago. Here we are.

Nature published the study.