Researchers have finally managed to shed light on the body structure of this strange creature, but biologists still have no idea how they got it.
The ocean is home to many amazing and strange creatures; for example, this unusual, multi-armed creature that has puzzled biologists for decades. No, we’re not talking about an octopus, but a starfish belonging to the echinoderm family known for its spines and cones, Inverse writes.
Many animals on earth, including humans, have a bilateral body structure. In simple terms, if you cut them in half, you get approximately symmetrical halves. However, echinoderms, as a rule, have a five-rayed body structure. That is, their bodies are arranged in a pattern that repeats five times around a central axis.
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It is also part of the larger deuterostome family of echinoderms, and many have bilateral symmetry. This has baffled scientists trying to understand how echinoderms such as starfish evolved from their humble bipedal origins to a five-armed body.
As a result, scientists suggested that starfish probably lost their bodies at some point in their evolution and became just heads. In a new study, an international team of scientists examined the genetic code of sea stars in search of some unexpected answers.
The team found that the genes in the starfish’s body are somewhat reminiscent of deuterostomes, with the middle part of each arm resembling the “head” region. However, the team did not find gene expression corresponding to the “trunk” or middle part of the bilateral body structure. As a result, scientists hypothesized that starfish lost their bodies for some incredible reason and turned into a cluster of heads.
The starfish appears to be missing a spine entirely and is easier to identify as a head crawling on the seafloor, according to Laurent Formery, lead author of the study and a postdoctoral researcher at Stanford University’s Hopkins Marine Station.
Remember that scientists have been trying to solve the mystery of the starfish for decades. They had previously put forward various theories to explain how the starfish achieved this shape. One of them, for example, suggested that echinoderms were able to reuse the genetic blueprints of their ancestors to create a unique body structure.
Another theory suggests that these creatures managed to preserve the same genetic plan of deuterostomes, but slightly improved it. Another theory is that the top-to-bottom axis of echinoderms is the same as the front-to-back axis of their ancestors. Note that this idea comes from examining where certain genes are active in echinoderm larvae.
The real problem was that echinoderms were surprisingly different from each other; in fact, even basic genetic and fossil comparisons with other animals are quite difficult. As a result, Formeri and his colleagues took a different approach: They examined how specific genes responsible for body structure were used in the starfish Patiria miniata. Note that these genes are quite old and, as a rule, do not differ much in different animals, including humans. In fact, it is these genes that are responsible for the structure of the head, body and tail parts over thousands of years of evolution.
The results of the study showed that the patterns of gene activity in the young starfish did not match what scientists expected to find. These genes were not working as well as in other sea stars, and scientists were actually able to discover a completely new pattern called the “ambulacral-anterior” pattern.
In this model, the team found genes active in similar regions in the human forebrain and other bilateral animals. Moreover, they were also active in the center of the starfish’s arms. Genes active in the human midbrain were active towards the arm edges of the starfish. At the same time, scientists found almost no active genes responsible for body structure.
The team states that they were able to classify the starfish’s body structure, but unfortunately scientists still do not understand how and why starfish should abandon their bodies, leaving only their heads. Scientists also believe that these changes probably occurred through a long, slow process rather than a massive, sudden repurposing of genes.
Previously Focus He wrote that in “Jurassic Pompeii” scientists discovered alien-like sea creatures.
Source: Focus
Ashley Fitzgerald is an accomplished journalist in the field of technology. She currently works as a writer at 24 news breaker. With a deep understanding of the latest technology developments, Ashley’s writing provides readers with insightful analysis and unique perspectives on the industry.