Where religion and evolution go hand-in-hand

The Zoque people of southern Mexico greet the rainy season with a religious ritual that involves poisoning a stream that runs into the nearby Cueva del Azufre, and gathering up the bounty of cave fish that float, anesthetized, to the surface. Those fish—considered gifts from the gods of the underworld—help keep the Zoque fed until crops grown in the rainy season can be harvested.

But centuries of annual die-offs, caused by a single, locally sourced poison, have functioned as a driver of natural selection. Today, researchers found, fish that live in Cueva del Azufre—downstream from the point where the Zoque poison the water—are becoming resistant to that poison.

Fish exposed to the annual ritual indeed proved more resistant to the toxin than fish that lived elsewhere, able to swim in poisoned waters for roughly 50 percent longer. As such, the poison from the ceremony apparently has over time helped select fish that can tolerate it -- fish that cannot get captured and killed by the Zoque.

This is more than just a fascinating look at evolution in action. The local government recently banned the fish harvest ritual, out of concern over its impact on the fish population. The researchers hope their data will help explain what the ceremony actually does to local fish, and maybe lead to a compromise that would allow the Zoque to keep their traditions, and their rainy season food source.

Recommended on Submitterator by Charles Q. Choi, who is also the author of the LiveScience story about this research.

Image: Some rights reserved by bensonkua

• [Oren Beck]

  Think of it as Evolution in action.

  IIRC the phrase was a bumper sticker :) And, a few other uses. One as a story element.

• [Gutierrez]

  So would this be an example of sustainable organic aquaculture through he use of neurotoxins?

• [hadlock]

  Is this straight up evolution, or simply adaptation?

  • [Trent Hawkins]

    Adaptation is an evolutionary process.
    So, I’m not too sure what you meant by that comment.

• [kromekoran]

  that fish is freaking me out, man. crazy-eyed fish, looking to jack my Sudafed I bet.

  • [Maggie Koerth-Baker]

    Surprised fish is surprised.

    • [insatiableatheist]

      He doesn’t look surprised. He looks downright pissed-off. Probably because they took him from his chemical bliss to photograph him in a tank.

    • [mdh]

      stunned fish is stunned

• [Srikanth]

  the title of the post immediately reminded me of a Telugu language class where our teacher told us how the incarnations of Hindu god Lord Vishnu follow the evolutionary pattern.

• [Anonymous]

  This would explain all of those dynamite resistant
  lake trout found throughout West Virginia, Kentucky
  and Tennessee.

• [vmaldia]

  “Is this straight up evolution, or simply
  adaptation?”

  if it is passed through the genes to the later generations, it could be evolution

  if its not, like muscles caused by body building or calluses caused by manual labor it isnt evolution

• [Trent Hawkins]

  Reminds me of the Heike crabs mentioned in Cosmos:
  http://www.youtube.com/watch?v=RiNKt6gcEM8

  skip to 4:50 if you don’t like the history lesson behind it.

• [RREugen]

  They used to do something exactly like this in Bogrotavia, but they used donkeys to pull the release levers, or maybe the whole point of the thing was to obtain donkeys. I’m not sure, we’re talking mid 19th century esoteric experiments. But it was pretty much like the above, with the bug-eyed fish and all.

• [Moriarty]

  And how’s the poison immunity of the Zoque people coming along?

• [Anonymous]

  Anyone that doesn’t believe in microevolution is an idiot… and that’s all this is… it doesn’t prove/support macroevolution.

  • [Anonymous]

    Fortunately nobody believes in macroevolution either, just microevolution over very long periods of time.

• [necaver]

  What’s really fascinating about this cave (also known as Cueva Villa Luz) and these fish is that their ultimate source of energy is from the H2S coming up in the cave. There is a whole chain of organisms dependent on chemical energy, with man at the top of the pyramid.

  BTW the stream flows OUT of the cave, not into it.

• [IronEdithKidd]

  Are these fish also resistant to fishing lures, hooks and nets?

• [Anonymous]

  Evolution? Pssshhhhtt… The poison immunity is just compensation from God to the remaining fishy survivors.

• [dragonfly10305]

  That fish looks very little like a Mexican cave fish, and very much like a telescope-eye goldfish.
  (Which, incidentally, were bred for that trait by humans…)