Solve the starfish head puzzle

The researchers immediately pose the question: If you had to put a hat or cap on a starfish, where would you put it? It is difficult to say, because most organisms are designed on a bilateral and symmetrical plan, with a head, torso, legs or paws running in pairs and sometimes a tail. But starfish are not like that. It follows a pentagonal model, that is, with five branches. Where are the head, arms and torso? Finally, American researchers led by Frenchman Laurent Fourmery were able to uncover the mystery.

This requires the use of very modern technologies. Biologists first cut starfish branches into small strips, determining that they would grow back. From these tips, they used high-tech molecular and genetic techniques to understand the structure of the animal. Thus they were able to create a 3D genetic atlas of starfish.

A new piece of the evolution puzzle

The first surprise is that starfish do not have a trunk. As for the head, it is not one head, but rather several heads, distributed throughout the animal. The starfish has a kind of head in the middle of each branch, and also a head in the middle.

If the mystery is solved, what’s the point of knowing it? Research usually focuses on groups of animals that are similar to us. But according to my authors this studyBy focusing on what is familiar, we are less likely to learn something new. Sea stars have an advantage: we know almost nothing about them, neither their evolution nor their role in the evolution of species. Laurent Formaire concludes: “Here, we now have a new piece of the puzzle about the evolutionary tree.”