Don’t tell us that “survival of the fittest” was a myth.  What?  All those genocides for nothing?

In a story that could be called “survival of the dudest,” PhysOrg now tells us, “Ancient, bottom-dwelling critter proves: newer isn’t always better.”  The dude in the story is a tiny sea creature called a rhabdopleurid.  An ancient one of these dudes is being called “an ancestor of more elaborate species that have since died off” called graptolites, a kind of pelagic (free-floating) plankton.  Apparently all that fitness exercise never paid off.  “Tiny sea creatures called rhabdopleurids reside on the ocean floor, building homes of collagen on the shells of dead clams, the article states.  “Rhabdopleurid colonies are small, and the critters are by no means the dominant animals in their ecosystem.”

The article claims that the simple dudes have survived for 500 million years, while the more elaborate descendents went extinct.  There’s a lesson here for fitness freaks, explained Charles Mitchell:

“We think that change is always going to lead us to a better place, that evolution is always going to lead to something better,” said Mitchell, a University at Buffalo geology professor. “But all this progress in making all these wonderful pelagic graptolites didn’t lead them to take over the world. They didn’t survive, but these simple dudes, these bottom-dwelling creatures, did.”

Sure enough, the paper by Mitchell and team found that rhabdopleurids “were some of the most primitive graptolites that ever existed.”  What’s the use of working so hard on the evolutionary treadmill to get fit?  “While their zooplankton relatives evolved rapidly, splitting into many new species and evolving many new traits, rhabdopleurids pretty much stayed the same over the course of history.”  And thus they survive to this day, 500 million years later.  “The rhabdopleurids survived and are still around today, living in areas from Bermuda to the Bering Sea” while the fancy zooplankton graptolites all went extinct….

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