Gene Sequencing Reveals Starfish Evolved to be Mostly Head, Lacking Torso and Tail

Genomic study upends assumptions about sea star anatomy, suggesting these creatures evolved by losing their trunk-like torso and now primarily consist of head-like cells, opening new avenues of research into their unique symmetry and evolution.

Sea stars, or starfish, evolved their distinct star shape by losing the genes related to torso and tail, essentially becoming mostly 'head'. This revolutionary finding upends commonly held beliefs about the animal's anatomy.
Starfish are not technically fish and the term 'arm' for their extensions might be a misnomer based on human anthropocentric view. Despite their peculiar shape, starfish and humans share an ancestor dating back 600 million years.
Molecular analysis was carried out using innovative techniques such as RNA sequencing and spatial transcriptomics, with the results showing genes related to the development of a 'head' found across the body of a starfish, and those associated with 'trunk' and 'tail' largely absent.
This groundbreaking research opens up new areas of exploration in the understanding of starfish and other echinoderms' unique symmetry and evolution. This could also provide insights into the nervous system's evolution.
The study was funded by organizations including the Chan Zuckerberg Biohub and NASA, highlighting broader interest in understanding life evolution, both on Earth and in outer space.