An exotic variety of jellyfish dubbed an "alien of the sea" is giving scientists a new view of early evolution and how nature designed and evolved nervous systems.
The creatures, known as comb jellies, evolved their distinctive nervous system in a way that sets them apart from all other species in the animal kingdom, suggesting nature found more than a single way to create such systems and did it not just once, researchers say.
Published in the journal nature by University of Florida scientists, the genetic study of the comb jellies provided clues to how they are able to regenerate lost body parts and even regrow a simple brain.
"This paper proves, on a genomic basis, they're truly aliens," says university neurobiology scientist Leonid Moroz.
"If you met an alien you would assume it is radically different from us," Moroz says. "There is no need to wait -- these aliens are in our backyard."
In contrast to the evolutionary pathway toward neural circuits taken by the almost all of the animal kingdom, comb jellies, also known as ctenophores, evolved to possess muscular and neural structures that were genetically completely different.
Although the jellies possess a complex nervous system, the chemical language it uses to develop and operate it is completely different than that found in any other animals.
The split in the evolutionary paths to complex nervous systems likely happened at least 550 million years ago, since fossils similar to modern comb jellies have been dated to at least that old. That age makes them one of the oldest evolutionary examples of complex life.
The fact that they've evolved a completely novel way to create a brain, with different neural circuits and behaviors, could open new avenues of research into bioengineering, Moroz says.
And the findings could go beyond just understanding evolutionary processes, he says; they could yield new ways to study and understand human diseases like Parkinson's or Alzheimer's.
"What if we could not only slow the progression of Parkinson's or memory loss in aging, but reverse it?" he asks. "Ctenophores show us that there is more than one design for a complex nervous and muscular organization."
"Nature is much more innovative than we thought."
