Scientific ignorance in the U.S. - The article, which is behind a registration wall (bugmenot to the rescue), talks about the classes not of economy but of knowledge in the United States.
“Our best university graduates are world-class by any definition,” he said. “But the second half of our high school population - it’s an embarrassment. We have left behind a lot of people.”
This article, frankly, is frightening. Having intellectually matured while guided by an excellent university, I continually lose site of what the average person simply does not know.
One adult American in five thinks the Sun revolves around the Earth, an idea science had abandoned by the 17th century.
The concluding remarks are the icing on the cake of despair: look for the response Jon D. Miller gets to his radio apperances.
The ideas for the following theory have been steeping in my head for a while. And since I’m doing something similar to kottke’s operation clear all browser tabs, you get to read my thoughts on the topic. See, the theory is about why we have a different density of hair on different parts of our body. To begin: evoultionary biology dictates that the different hair densities on our bodies must have conferred an advantage to individuals who had favorable distributions of said hair.
Now, that previous sentence needs some clarification. First, the “advantage” asserted above is an evolutionary term. It refers to a key tenet of evolution: survival alone is not grounds for evolutionary selection - an enhanced ability to survive and reproduce indicate advantageous adaptation. To that end, I offer an oversimplification: the fish who developed a light sensitive patch on its body, the precursor to eyes, could beat out its cousins at finding food… but the fact that this allowed it to reproduce at a higher rate (not simply its survival) was what provided the impetus for the slow change in the gene pool ultimately resulting in eyes. Another point in that original sentence: a “favorable distribution” of hair varies from region to region, an idea which I will elucidate shortly.
Common Sense
This brings us to generally accepted observations: we have hair coverage at a higher density on the top of our forearms than on the bottom, extremely large amounts of hair on our heads, hair surrounding our reproductive organs, hair sprouting from our underarms, and no hair on the bottoms of our feet. Generally, men have denser hair coverage than women. Furthermore, hair coverage varies very widely between different ethnicities. A typical black man has relatively little hair coverage when compared to a typical (sterotypical, even) Italian man. What unified theory could explain all of these observances?
I’ve mixed concepts from my animal behavior, microbiology, immunology, and biochemistry courses in an attempt to propose an outline of a unified theory of human hair coverage. First, we’ll cover that theory, and then I will attempt to explain all of the observations from above using the ideas set forth.
History
Let us begin with early Homo sapiens. We all know they toiled in a hunter-gatherer lifestyle, constantly exposed to the sun’s beating rays. Aside from being uncomfortable and causing visible signs of aging, sun exposure has a far more serious effect: DNA damage (specifically dimerization of adjacent thymines bases). Now, these dimers can be repaired by excision systems (clipping out the damaged region), but we unlucky humans don’t have photolyases, which are enzymes optimized for fixing sun damage. If we did, it is likely that we would never ever get skin cancer from UV rays. So it goes. That’s not to say we’re entirely powerless against fixing DNA damage - we repair tremendous amounts of damage to DNA on a daily basis. However, it is important to avoid overwhelming our repair systems, because the cumulative effects of DNA damage result in one thing we all know: cancer.
The Theory
So, we end up here: hair, a non-living collection of proteins just above our skin’s surface, filters out sunlight/UV rays, thereby reducing DNA damage and ultimately reducing the risk of cancer. A lower risk of cancer allows the ancient human to pass this desirable pattern of hair on.
Application
Applying this theory is the fun part: we’ll take the forearm hair example first. The top of your forearms are exposed to the sun, yet the bottoms of your forearms remain facing the ground, or held in at the body, dramatically reducing sun exposure. Less sun exposure, fewer mutations - thus, less hair required. Why less hair? Well, why waste precious energy on pushing hair out of the skin when there is no benefit? Oh, and I see where you are headed you wily tumbledry reader: how does this sun exposure thing explain underarm hair? Think about what is directly beneath your armpits… right below the skin there… yes, it is an interesection of many blood vessels, but more importantly - what’s there? Ok, I’ve given you plenty of time to wikipedia into the article on lymph nodes. Specifically, you may have noticed the axillary lymph nodes sit right beneath your armpits. This is one of the reasons it hurts so much to get pinched there. Anyhow, the lymph nodes play key roles in your immune system, and this specific group has been linked to breast cancer. Thus, one could say that hair growth in the underarms mitigated carcinogenic UVDNA damage in ancient humans.
The theory seems to continue working, too. Hair around the reproductive organs would prevent sun damage to critical gametes in males, and prevent tumors from blocking the birth canal in females. A dearth of hair on the bottoms of the feet would occur as sun exposure in that region is so low. Hair on our heads? Protects from brain cancer. Hair along the center of the chest? Well, this would shade the sternum, which is extremely close to the skin, and would be susceptible to DNA damage (bone marrow, etc.). For the ladies among you wondering where your chest hair went, we move to the next point.
Men vs. Women
So, why have women ended up with less hair than men? Well, less testosterone produces the secondary sex characteristics we associate with females, but we are looking for an evolutionary reason for hair coverage. To this end, I would guess that if the men were our hunting, running over the plains and such in open sun, the women could select sheltered areas in which to anchor the community. This shelter from the sun could result in the “men are hairier than women” result we observe today.
Ethnicities
Those with the darkest skin color are best adapted to a life under the sun. Thus, there’s no point in making excess hair all over the body. Those of Italian ancestry have paler skin, yet a lot of sun exposure, which necessitates a lot of hair. Scandinavians - I know you think you’ve got me there - they are quite pale, why aren’t they quite hairy to compensate and block the UV rays? The cold areas of the world far from the equator never have very intense sunlight, plus any culture surviving there would have to develop a comprehensive garment system if it was to survive. Clothes for thousands of years prior to those in the south = less hair.
Another Theory
I did run across an extensive and surprisingly interesting scientific discussion about hair, which was kicked off in a post about the complications of Brazilian waxing. Though mostly anecdotal in nature, the opinions and perspectives of the commenters were frequently backed up by real science. This situation is the polar opposite of one like, say, YouTube comment threads, which will forever go down in history as putrid cesspools of thoughtless idiocy. Don’t get me wrong, though, I love the videos there—just not the comments. Anyhow, a man who does research on commensal skin bacteria wrote in that thread:
The reason humans have hair in the places they do, is to provide a proper niche for commensal skin bacteria.
These are the autotrophic ammonia oxidizing bacteria (the subject of my research and my blog).
Of course bathing does remove these bacteria, and because they are slow growing (doubling time ~10 hours),
they take a long time to grow back (a month or so without sufficient innoculation).
Interesting stuff, but most interesting is the folllwing (emphasis mine):
They suppress heterotrophic bacteria probably by oxidizing quorum sensing compounds.
If you have a sufficient biofilm of these bacteria, you don’t need to bathe to remove the heterotrophic bacteria that cause odor.
This is a fascinating direction of reasoning as to why hair is where it is. You can read his full comment here.
Closing Remarks
That is about all I have to say about hair. I am writing this portion because when I outlined this post, I wrote “closing remarks” as a section, like I would have something meaningful to say here.
Joseph Bertolozzi Plays the Franklin D. Roosevelt Mid-Hudson Bridge - I don’t mean he’s playing at the bridge, I mean he’s playing the bridge. In a project not unlike Bill Fontana’s sound sculpture “Oscillating Steel Grids along the Brooklyn Bridge,” Mr. Bertolozzi is in the process of sampling sound using contact microphones from the bridge itself. Certainly, this concept would be cool on its own: if you listen to the movement Bridge Funk, a small piece played on the bridge used to gain approval for the project, you’ll find that the music sounds very, very cool—much more musically intricate than you would imagine a bridge sounding. However, this project will not simply culminate in a digital collection of sounds assembled into music. The composer is writing out an entire 40-60 minute score to be performed live and piped into a nearby park in 2009.
“I’m actually using the bridge as an instrument,” he said. “It’s not aleatory. There’s no guesswork. I have an army of percussionists playing a percussion instrument.”
Free programming tips - Really great advice on programming, including waiting to optimize until after you find the slow spots.
And don’t write longer, more obtuse code because you think it’s faster. Remember, hardware gets faster. MUCH faster, every year. But code has to be maintained by programmers, and there’s a shortage of good programmers out there. So, if I write a program that’s incredibly maintainable and extensible and it’s a bit too slow, next year I’m going have a huge hit on my hands. And the year after that, and the year after that.
I especially like his emphasis on robustness. I try to think of the same ideal of “bulletproof” code when I write my CSS (which, true, is markup styling… which is by default more error-tolerant). Regardless, great information.
I sat down next to Mykala on the Fourth of July, and casually asked her a question while I did a few trivial computing tasks. “Did you notice a difference in speed for tumbledry?” I was overjoyed to hear her response: “Yes, actually—I noticed it seemed a bit faster.” Her single comment made the struggle to resolve all of the lags in delivering tumbledry at high speed to you lovely readers worth it. Now, I have thought for a while how to make an analogy that will keep the attention of the non-programmer readers of this space. You see, historically, the problem is that these techy posts become so heavily jargon laden that they are neither digestible nor desirable to anyone who doesn’t develop web applications for a living. So, yes, I could ramble about PHP, gzip compression, query optimization, JavaScript libraries, and Dean Edwards’ amazing packer… but I would alienate many, and bore many more. So, I present an analogy that is a bit rough around the edges, but should still get the point across.
Imagine your web browsing experience is similar (analagous even, har) to that of a diner at a restaurant. Your web browser is the menu: from it, you order what you want to consume. Now, let’s say you’ve had a long day at work and after you sit down and have a nice drink, you decide to order up a hot and fresh dish of tumbledry. Your waiter/waitress runs off to the kitchen and puts in an order for tumbledry. Now, these are pretty good chefs in the kitchen—they’ve had years of experience. Therefore, they can cook a dish of tumbledry in the region of 0.001 to 0.2 seconds. That’s fast! Certainly, they could do with some optimization (sometimes Alex gives them rather convoluted cooking instructions), but despite the byzantine hoops, they do pretty well. However, for some reason, it still takes forever for you to receive your tumbledry! That is (was!) a shame. And that’s where the optimization came in.
You see, when things were slower, the dish of tumbledry was served in many pieces, forcing your poor waiter to have to run back and forth repeatedly. Sometimes, he even had to grab things from other restaurants! How gauche. Plus, the limitations of a single amateur waiter apply roughly to your browsing—dishes are generally grabbed only one or two at a time. This had the effect of slowing down the process, ultimately increasing the time it took for your dish to be fully assembled at the table. On top of that, massive, inefficient kitchen paraphernalia had be carried by your intrepid waiter: imagine him hauling an entire iron kettle of hot soup just to serve you your individual portion. Pieces of the kitchen were coming with the food, too—maybe on occasion you’d get a spatula, or in the worst case scenario, a dish rag. After all this, the table was in danger of collapsing.
That’s when I stepped in and said… “this is ridiculous.” Away with you, iron kettles! I’ve had enough of this! Now, imagine that instead of making 40 mindless trips, your waiter (who, we must admit, continues to appear a little inexperienced) only has to make a few runs to deliver your entire tumbledry. The chefs are still fast—and now you can benefit from their speed. The weight of what the waiter carries has been lightened significantly, and all the useless crap has been kept in the kitchen, or removed entirely. Sounds great, no? It gets better. Now imagine another little trick allowing the waiters to get you your identical food as before, but even faster. We’ll call it “le compression.” On the way out of the kitchen, the chefs add a little potion to the food to shrink it, say, to the size of a Pez dispenser. When it arrives at your table, you watch in amazement as it magically grows back to its previous size! Thus, by utilizing the power of this little trick, the waiter can carry more at once, and decrease the time required for your meal to be fully assembled.
Finally, there is one more thing that can be done to speed up service. If the waiter and the chefs get together and realize that you frequently order the same dish (let’s call it tumbledry ala mode), they can agree to keep pieces of it at the table, ready to jump into action with little delay. For example, they can’t store ice cream itself at the table, but they could certainly keep the toppings nearby! Voilà, speedier service!
At this point, you might want to know the actual hard stats showing the improvement of which I speak. Here is what was found: the front page of tumbledry used to be very close to 1,000 kilobytes. By web page standards, this is massive. Consider, for example, that the last song I purchased on iTunes is 3,000 kilobytes. Do you want to load a third of a song each time you visit a web page? Holy long page load! So, one of my goals was to make sure tumbledry could be comfortably served up to mobile phone users (iPhone users, really). The connection they get is about 10 kilobytes per second. For the mathematically inclined among you who have skipped ahead of me — yes, it’s that bad — it would’ve taken mobile phone users 1 minute and 40 seconds to load the bloated tumbledry of yesteryear, with dial up users clocking in even slower times - around 4 minutes and 45 seconds. Try to stare at your screen doing nothing for that long, without deciding never again to visit this website.
Therefore, I’m proud to announce that the front page of tumbledry now clocks in at a svelte 150 kilobytes. Averaging out over different conditions, this represents a reduction in size of about 81% Put another way, tumbledry is over 5 times smaller than it used to be. Now, those lucky iPhone users should only have to wait 15 seconds for a full page load (plus, they’ll be able to read things before that).
So, the cooks are fast and the waiter is much less overworked — let’s serve up some delicious delicacies!
Genius nutcracker - Put a nut on the stainless steel base, place the flexible rubber dome on top, and then mash the rubber dome with your fist. Tada, the nut is cracked.
