Something I learned today...

This is a pretty random post, and it involves fish evolution.

In science class today, we hatched a video about caves. How they're formed, growing, etc. Then it came to a part where it described the inhabitants of caves. The narrator was describing caves as being islands, but islands or pockets of water surrounded by land. One of the fish named was a cave angelfish:

It lives in cave waterfalls.... On the actual waterfall part. They have little projections on their fins that a used to clime the slippery limestone. They have evolved to the point of losing pigmentation and even eyes. Instead, they have interceptors, which sense heat around them, and turn other living creatures into a red spot. That's how they hunt prey.

Then there's the INVINCIBLE Mollie.
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There is one cave in Mexico that people can not fully excavate. It is a mostly underwater cave, and the water contains a lot of Sulfuric Acid. This acid can burn clothing, skin, goggles, etc. Even in the beginning, it's risky. People need to wear gas masks when touring the cave above the water column. There is one fish that can survive this harsh water: a Mollie. Just Like the cave angelfish, the Mollie has lost it's pigment, but not it's eyes. Its skin isn't harmed bay the acid at all, and its even breathing it in. How weird is that?

Its hard to believe that there are fish specced out there that have evolved this far.

 

Wow thats awesome!

 

Very cool! I love movies and such like this, I am taking an evolution class this semester I cantwait!

 

Some teacher showing Planet Earth, "Caves" again. Must be Friday in Science class! I've seen that episode.

 

I do too. everyone else in class was asleep, especially when class starts at 7:00... I was wide awake. Who wouldn't want a fish that can climb a waterfall? They Ned to start selling them on live aquaria.

 

LOL, thats hilarious. It was interesting for the most part.

 

Oh yeah, those mollies are cool little guys. The mollies are actually ok to live in a slightly sulfuric environment as-is, though, as it's not pure sulfuric acid - meaning the pH isn't unsurvivably low.

The really interesting part about them is that there's been a ritual going on in the region for about a thousand years, where worshipers dump a mix of lime and barbasco root into the cave. That barbasco is a toxin to normal fish, but not the the mollies that have been slowly adapted to living in it. Texas A&M did a study on the fish population, and found that their offspring would allow them to survive in barbasco laden water for longer periods of time than unrelated fish, implying a genetic change that prevented barbasco from affecting them as strongly.

 

That's crazy. Its like having skin that cant be pierced, or being able to breathe in high altitudes. Wo knows what the human will be like in millions of years. It makes me wonder...

 

at this rate non-existent.

 

It's really like being able to survive a frequent, regular dose of ricin, or some other toxin. Not something nearly as incredible as unpiercable skin. It took them many generations to get to that point, too. Just imagine if a population of people lived on top of mount everest (barring concerns about food, water, etc) for as many generations as those mollies lived in the cave (probably about 200 generations of mollies can live in the time it takes for humans to go through one generation, so tens of thousands of years). Huge numbers would die in the process.

And if you think humans will exist in their current form in a million years...