Noodles.

[theiform]

I'm making dinner tonight, and dinner is therefore going to be spaghetti with meat sauce because I love spaghetti with meat sauce and because my mom picked up a mix of ground beef and ground pork that I am most interested in trying out. Lunch was Kraft Dinner (which as a Canadian I must assert is superior to all other Kraft Mac and Cheese products

Comments

[theiform]

In the caves that were full of water but had so little light in them, so many of the animals that weren't fish had evolved so as not to need eyes. There was a salamander that looked like an axolotl except for its snout, and it was just...lacking eyes. No eyes anywhere. I kind of wonder what kind of genetic mutation would cause that, and how it became so widespread a mutation that the whole species now just has no eyes. My brother and I figured it was because eyes are just one more vulnerable spot, the ones without eyes just survived longer. It didn't seem like there were many predators in the cave so maybe it just got rid of a spot that prey were lashing out at as they tried to escape.

I'd be really interested in seeing these arthropods that developed to specifically for those environments. There was another example of that in a deep sea episode, where the heat vents from volcanoes underwater bred bacteria that could survive in the heat, and shrimp or I think squid or other species would flock there and create an ecosystem just around the vent, but with all the shifting under earth's crust, the vents could just up and close off any time and then the whole thing would die off just like that.

Aren't black bears pretty docile? We have those around here and I don't hear a whole lot about them, other than, "Yeah it wandered into my yard and wandered back out again..." You hear more about coyotes getting cats and little dogs left to run around in country properties. Hawks sometimes too.

[rubyelf]

Organisms that live in places where there's no use for eyes lose them basically because there are lots of things that can go wrong in making eyes (or any other body part). Normally, evolutionary pressure eliminates mutations that hinder the functioning of eyes. If you live in complete darkness and have no use for your eyes anyway, any mutations to the genes that make eyes will not be penalized by evolution... it's literally blind to the error because the organism isn't at any disadvantage. While their above-ground relatives would suffer from even a minor mutation that hindered their eyesight, cave-dwellers don't suffer at all... the mutation is basically neutral, and our DNA is littered with neutral mutations, cluttered messes of genes that were no longer used and have been allowed to mutate freely because there's no evolutionary pressure to conserve them. So eyes just disappear gradually over time as evolution fails to correct genetic errors in eye development. Also, eyes are "expensive" in the sense that they use energy and resources (including processing space in the brain) that could be used elsewhere. Organisms living in complete darkness and without eyes have usually dedicated most of the part of the brain that used to process visual signals to processing other senses. So it isn't one mutation that just causes the organisms to lose their eyes... it's a long process of small mutations that aren't corrected because there's no evolutionary "penalty" for the mutation, so they accumulate until the eyes are nonfunctional and then nonexistent.

Black bears prefer to avoid confrontation with humans. However, they will attack if they are cornered, such as if you accidentally stumble upon one in close quarters like a cave. They are large animals and even though they aren't very aggressive, even having one smack you out of the way trying to escape could kill you, so it's better to avoid putting them in a situation where they feel threatened. They often get to our wild raspberry patches before we do, and we definitely don't argue with them about it. When they're in the yard we will go outside and take pictures from a respectful distance, but that's a situation where the bear can run off into the woods if it feels bothered. Usually they just ignore us. They are apparently more likely to be moody and bad-tempered when they're hungry (like when they've just woken up in the spring), and females with cubs are very protective.

Axolotls are actually perfectly normal salamanders, except that they have a single mutation that causes them to fail to produce the hormone that signals them to transform into adults. They reach full size and reproduce without ever growing out of the juvenile phase. Researchers dosed them artificially with the hormone they're missing and they matured into adult axolotls, which had never been seen before, but closely resembled another local species. They are probably closely related, and the axolotl is an off-branch that became isolated and then developed the mutation that made them remain in the juvenile phase while still being able to reproduce. It's interesting that all the genes to turn them into normal adult salamanders are still present and ready to go, and will switch on perfectly normally when dosed with the missing hormone.

[theiform]

I really wanted to take time to respond to this, because I was reading it and basically all I could think was, "Oh, that makes sense, that's so cool," over and over, but then I got to the last paragraph and I read it out loud to my brother and our friend, and they in turn reminded me of this...

www.youtube.com/watch?v=MxA0QVGVEJw

I give you...the axolotl song.

[rubyelf]

That is so weird and hilarious... but obviously researched, too, because they did use the term neoteny, which is the scientific term for the elimination of the adult form from the life cycle of an organism, which is what axolotls do.