Further to the comb jellies having a separate course of evolution from other animals, here’s Amy Maxmen at Nautilus:
In an essay for Nautilus called “Evolution, You’re Drunk,” I described how hypotheses entrenched in the notion that evolution leads toward increasing complexity have recently begun to teeter. Now Moroz’s study adds another shove. It seconds the finding that simple sponges, long placed at the base of the evolutionary tree, actually evolved after the sophisticated comb jelly group arose. The story of how complexity evolves is more complex than scientists realized.
Furthermore, the brain—the epitome of complexity—seems to have sprouted up at least twice over evolutionary time. This clashes with the traditional notion that complex, multifaceted features come about in a very specific way, and each emerges just one time. “What everyone has said about complexity is wrong,” Moroz says. “It can happen more than once.”
If traditional evolution theory is this wrong, a theory of information in life forms is more needed than ever.