Religious Ceremony Leads To Evolution of Cave Fish

An anonymous reader writes "A centuries-old religious ceremony of an indigenous people in southern Mexico has led to evolutionary changes in a local species of fish, say researchers at Texas A&M University. Apparently since before Columbus arrived, the Zoque people would venture each spring into the sulfuric cave Cueva del Azufre to beg the gods for bountiful rain. As part of the ritual, they released into the cave's waters a leaf-bound paste made of lime and the ground-up root of the barbasco plant, a natural fish toxin. The rest is worth reading, but the upshot is that the fish living in the cave waters eventually got wise, genetically speaking."

Already known

[jihema]

It was already known that evolution by natural selection could be triggered by human activity. Industrial melanism (e.g. the Peppered Moth) is a famous example.

Re:Already known

[Anonymous Coward]

The Peppered Moth is a famous example, but a dreadful one. There are several problems with Kettlewell's experiment [wikipedia.org], many of which are pointed out here: Second Thoughts about Peppered Moths [arn.org]

Re:Religion causing evolution....

[Anonymous Coward]

This is largely a straw man argument. It's not necessary to understand the biochemistry or the underlying mechanisms in order to deduce an evolutionary response, it's sufficient to note that the fish are more resistant to the leaf-throwing than those upstream. Darwin deduced the fact that evolution happens without biochemistry or knowledge of genetic differences.

And don't tell me that 'evolution is just a theory'. In science a theory describes a large number of observations with a simple, predictive model. Theories are falsifiable but not provable. Despite many attempts, evolution has not yet been scientifically falsified and it explains a multitude of observations really, really well - including this one.

Re:But they're still the same species fish, right?

[SuricouRaven]

It's one rock-fall blocking the river away from that happening. Population isolation happens.

Re:Article's stupid conclusion

[kalachakraa]

Yet that's the main point Rosenthal, one of the authors, is trying to make: "We tend to have this wonderful Pocahontas idea that before Europeans came in, everything was pristine and in harmony" but no such thing as "pristine" wilderness because humans have been radically changing their environment since forever. Therefore climate change alarmists and other environmental loudmouths moaning about species loss and soil degradation should just shut the fuck up. (And leave the thinking to Biology PhD.'s.) This is reductionist - it's called the Fallacy of Division. Specific changes to the environment, like loss of large prey animals, while doubtlessly catastrophic for the existing humans, was for the existing biosphere probably just a blip in a normally flexible dynamic (arguments for "keystone species" aside.) What INDUSTRIAL SOCIETY has done might appear to be just the same thing just a lot bigger. However because the environment (and life in general) is an emergent system and not just the sum of it's parts, you cannot scale up and down this way and expect to make intelligent decisions. Further, the "pristine wilderness" that the author ridicules is itself an emergent property of a functioning biosphere. Most people who spend enough time in those few parts of the world that haven't been deeply degraded by humans can feel it, and feel it's absence, despite not yet having tools that would specifically measure what we're feeling. That feeling of pure wilderness is certainly not just some lame projection of human society's materialist-moralist-sexist "Untouched and Pure" valuation of virginal young daughters. That's just an anthropomorphism, and Rosenthal's just calling Nature a slut. Asshole.

Re:Religion causing evolution....

[CharlyFoxtrot]

Indeed the paper talks about a "potential effect on gene flow" ("Our findings reveal potential effects of an indigenous cultural practice on three distinct processes: (i) dynamics within affected populations, (ii) gene flow among populations, and (iii) adaptive trait divergence between affected and unaffected populations.") Scientists are nothing if not careful.

Still the fact that this is an annual event with a high dose poisening instead of gradual long term exposure makes mithridization unlikely (IMHO, not a biologist.) The paper says : "barbasco is deposited inside the cave about 100 m from the cave entrance, from where it is distributed downstream and outside of the cave." so the poison would be washed out.

I see the guy has some of these fish in his tanks [sulfide-life.info] so hopefully he'll do a follow-up with specimens from the different populations bred in captivity under controlled conditions.

Re:Unuseful Definition

[Rakshasa Taisab]

I'm confused... how is selective breeding not evolution?

Hell, I'd even call it is Darwinian evolution where human selection is part of the environment.

Re:So...

[GNUALMAFUERTE]

Dude, I feel your pain. Evolution is so obvious, so evident, so undeniable. We experience it every day, even within our own families. And yet, you find people that tell you that there is "no proof of evolution", but he insists that there is more proof of the existence of an invisible man in the sky. Even when all evidence goes against it, he insists that there is only evidence for it. And does the opposite with evolution. Stupidity hurts because we try to understand them.