Annoying Questions I'd Like Answered...

name_here · Post by **name_here** » Tue Mar 31, 2015 1:27 am

Evolution isn't actually directional. There is no particular reason why something that has changed can't change back, and it takes fewer changes for a bird to become something with hands than it takes for a unicellular organism to turn into a bird. That said, it's fairly likely that the ecological niches for which hands are useful will be filled by things which are better-suited for them, quite possibly from the same common ancestor, unless there's been a mass extinction.

tussock · Post by **tussock** » Tue Mar 31, 2015 2:21 am

Evolution doesn't go anywhere in particular in the future, whatever works gets selected and whatever doesn't, doesn't. But it is totally directional in what we have now, embryos do one thing and then they do another thing and the second absolutely relies on the first being in place, in enormous chains where everything depends on everything that came before it.

The stuff which came first is older, because it was already there for the next step to be able to exist. Embryonic development is directional, and so is future embryonic development.

See, the fish that developed structural bones in their fins which lead to everything with limbs, they settled on four bones per spur with five spurs as a compromise structure for strength and flexibility, and the joints in those bones were tied together with tendons. The same tendons which tie my fingers together as I type this, because everything between the fish and me had those joints and needed them held together.

It's why there's three bones in your arm and twenty in your wrist. That's not optimal, it's just what was there after the fish got done stabilising it's walking fin, and when you want the flexible bits further from the body you can't just add a new joint between them, because that step is too primitive to modify without fucking up every step which follows it.

Evolution can do anything by adding more stuff on the end of any chain, and there's lots of them to modify, even add whole new branches, but it can't add a joint in the middle of what is now a fixed bone. Birds can no more re-articulate their ancestral fingers than we could grow a new joint in the middle of our femur. It can't happen. Niches have nothing to do with it.

Shrapnel · Post by **Shrapnel** » Tue Mar 31, 2015 1:46 pm

What is the difference between a reptile and a lizard? Is it like the difference between insect and bug?

angelfromanotherpin · Post by **angelfromanotherpin** » Tue Mar 31, 2015 2:18 pm

Reptile is a category which contains many animals, and not all of them are lizards: snakes and tortoises, for example, are non-lizard reptiles.

More specifically, Reptiles are a biological Class. Within that Class is the Order Squamata (scaled reptiles), and within that Order is the Suborder Lacertilia (lizards).

Shrapnel · Post by **Shrapnel** » Tue Mar 31, 2015 6:53 pm

Ah-kay. That clarifies things.

erik · Post by **erik** » Tue Mar 31, 2015 9:26 pm

And the obligatory xkcd as a footnote...

OgreBattle · Post by **OgreBattle** » Wed Apr 01, 2015 2:44 am

What is the functional difference between the hip structures of saurischian ('lizard hipped') and ornithishian ('bird hipped') dinosaurs? Why do the modern descendants of saurischians (birds) have different hips from their ancestors? What's the functional reason for modern day birds (descended from saurischians) having a hip structure different from their ancestors?

angelfromanotherpin · Post by **angelfromanotherpin** » Wed Apr 01, 2015 2:50 am

http://www.ucmp.berkeley.edu/diapsids/dinomm.html

The etymology behind the two names ("bird-hipped" vs. "lizard-hipped") is rather confusing, since some saurischians had bird-like hips, and ornithischians' hips were somewhat birdlike due to convergent evolution, not due to shared ancestry. Birds are apparently descended from saurischian dinosaurs, but have a reversed pubis like ornithischians do. Some close relatives of birds within saurischians have this same feature, too, so the ornithischian-saurischian dichotomy is not so simple. The names "Ornithischia" and "Saurischia" are used to refer to the common ancestry of their respective members. The names don't necessarily have to mean anything. They are just names, that's all.

Occluded Sun · Post by **Occluded Sun** » Thu Apr 02, 2015 8:27 pm

Why is human hair so long?

Most animals' hair stops growing and falls out after it hits a predetermined length. But human hair keeps growing. What's the deal there?

DSMatticus · Post by **DSMatticus** » Thu Apr 02, 2015 11:57 pm

First, you'll note that human hair, like human skin, isn't a single phenotype expressed by every human ever. The first humans had short, curly hair, and that trait hasn't disappeared and isn't going to disappear anytime soon. It's more prone to breakage (shorter, slower growth), circulates more air to the scalp (cooling) while more effectively blocking UV radiation (yay for less cancer), and has the ability to keep its shape when all but soaking wet (sweat resistant). All of those things matter less when you're living in a place like northern Europe, which could just as easily be populated by vampires for all the warmth and sunshine it gets. But having a giant head blanket will help keep your neck and shoulders warm, and straight hair will hang and cling to you in a way curly hair will not.

Also, there's some suggestion that for women long hair is something of a peacock's tail. Men go bald fairly often. Women go bald fairly rarely. It's possible the association between long hair and femininity might go very, very, very far back. When you combine that with the fact that most tribes reserved dangerous tasks for men in order to maximize their population growth (men can get any number of women pregnant; women can only carry one pregnancy at a time), the greater competitive pressure on women to secure long-term mates could have manifested in ostentatious displays of wastefulness. "Look at all the time and resources I put into taking care of my hair. Since I am also not starving to death, that means I am a better survivor than all the other people who also aren't starving to death but do not have such glorious hair to express their femininity." I.e., very similar to peacocks. "Look at this ridiculous thing. Have you ever seen anything so stupid and wasteful? It's a miracle I haven't been eaten or starved to death. But since I haven't, that means I am clearly a better mate than anyone else who also hasn't been eaten or starved to death but doesn't have a tail as ridiculous and stupid as mine."

Prak · Post by **Prak** » Fri Apr 03, 2015 1:36 am

Used to be the same way with weight for males- "Look how fucking fat I am. Clearly I'm an amazing hunter to be able to acquire the sheer amount of food I need to be a tub of muscle and lard while my kinsmen are fucking skeletons in leather."

DSMatticus · Post by **DSMatticus** » Fri Apr 03, 2015 2:03 am

To be fair, that's slightly different. The ability to build up an excess of fat and muscle signals to potential mates that you have been successful, but those are also resources your body has stored to help it function while running a calorie deficit (i.e. during a harsh winter). The ability to grow a giant tail that makes it harder to escape predators signals to potential mates that you have spent a bunch of resources trying to get yourself killed and failed, so clearly you're a badass. These aren't any ordinary signals of success, these are signals of success delivered by the mechanism of resource wastage and risk-taking.

Prak · Post by **Prak** » Fri Apr 03, 2015 2:26 am

Well, true.

Prak · Post by **Prak** » Fri Apr 03, 2015 4:56 pm

I'm trying to find a printer that can do what I want, and having trouble.

What I want for the game journals I'm working on is a cardstock cover, with an interior back pocket, an option to print an image on the cover, and saddle-stitching, but sewn rather than stapled.

I know a few of you have produced games, so if anyone knows of a printing service that could accommodate that, please help me out here.

MDT · Post by **MDT** » Sat Apr 04, 2015 7:24 am

What's being stitched exactly?

AndreiChekov · Post by **AndreiChekov** » Sat Apr 04, 2015 7:33 am

Has any person in the history of ever actually had a nosebleed from seeing something sexy. And if they haven't, does anyone know where this idea comes from?
I've never experienced a nose bleed from this, and I bleed from the nose quite easily. And, nobody I know has ever had this happen either.

Prak · Post by **Prak** » Sat Apr 04, 2015 7:42 am

MDT- So, saddle stitching is where the book is made of sheets folded in half and stapled in the center, like a cheap theater program. I want that to be sewn with thread rather than stapled.

Typical saddle stitching-

Moleskine Cahiers Notebook "saddle stitching"-

DSMatticus · Post by **DSMatticus** » Sat Apr 04, 2015 8:02 am

AndreiChekov wrote:Has any person in the history of ever actually had a nosebleed from seeing something sexy. And if they haven't, does anyone know where this idea comes from?
I've never experienced a nose bleed from this, and I bleed from the nose quite easily. And, nobody I know has ever had this happen either.

It's basically an old wives' tale sort of thing. Someone thought it would be funny to incorporate it into their art as a joke. As you can tell, their idea caught on and now it's a ubiquitous symbol for arousal.

Username17 · Post by **Username17** » Sat Apr 04, 2015 2:43 pm

Japanese people genuinely have higher blood pressure than Americans. So they probably do get more nose bleeds when they are excited than Americans.

-Username17

Meikle641 · Post by **Meikle641** » Sat Apr 04, 2015 8:13 pm

Wasn't it also more prevalent in the pre-WW2 era due to shitty diet?

MDT · Post by **MDT** » Sun Apr 05, 2015 9:26 pm

Prak: ok gotcha.

Have you tried picking up a couple of these saddle-stitched notebooks and getting in touch with the manufacturers?

Prak · Post by **Prak** » Sun Apr 05, 2015 9:43 pm

I talked to Picadilly, which makes the same sort of products as moleskine, but cheaper, and they could do it, the minimum order would just be 2500. I'm waiting for an email back about pricing. Moleskine would probably be prohibitively expensive.

It's certainly an option, but I'd prefer to be able to deal with a manufacturer directly and pay production costs rather than wholesale bespoke. I'm thinking I may need to make do with traditional saddlestitching with staples for now, and then try to make the ideal form happen later if the product succeeds.

hyzmarca · Post by **hyzmarca** » Sun Apr 05, 2015 10:27 pm

Ok, my seat keeps popping out of my chair whenever I shift my weight the wrong way, and it's very annoying to put it back together a couple of times an hour. What's the best way to bond two pieces of wood.

Carpenter's glue should work, but I can't really leave it clamped for 12 hours because A) it's my work chair and I have to sit in it and B I don't have any clamps. Nails have been a partial success, but haven't lasted very long before popping out because the wood is just too hard to make a deep hole in.

name_here · Post by **name_here** » Sun Apr 05, 2015 10:38 pm

Use a power drill to insert screws. It should only take a couple seconds and will hold very well.

AndreiChekov · Post by **AndreiChekov** » Mon Apr 06, 2015 8:01 pm

name_here wrote:Use a power drill to insert screws. It should only take a couple seconds and will hold very well.

this, except, apply wood glue before screwing.
if you don't have a powerdrill, you can probably rent one from a local business like home depot. Or whatever you have in your area, and that is usually cheaper than buying a new one.

If you just use screws, it won't last as long.

Edit: and now that I think about it. Liquid Nails (TM) would work better than most wood glues of the same price range.