Welcome to Dooce, everything I wish tumbledry to be - Her most recent post:
The only thing missing was a Google map of our house and a red pin sticking straight up out of Jon’s skull to signal HERE, HERE, HERE …
Thanks Mykala, for finding this blog.
I’ve written before about my extensive internal dialogue and my propensity to replay social scenes in my head, looking for ways I could have said the right thing. Shockingly, this character trait comes in handy sometimes, as recently evidenced at Lifetime Fitness. I was taking the weights off a bar on a squat rack, and I realized I did not have enough space for the remaining plates. To my left, a woman was using another squat rack, which had room for the plates.
Now, it’s generally good form to say something when you approach somebody else lifting (especially someone doing squats or standing shoulder presses, as she was) — this prevents you from being bopped in the head by a bar because the other person doesn’t see you. So with this in mind, I very nearly said, “Can I use your rack?” With milliseconds to spare, something told me that wasn’t the right thing to say.
I put the weights elsewhere.
Twins Separated at Birth - Parents say the doctors stole a baby, doctors say parents abandoned a baby. Either way:
The two girls, Andrea and Marielisa, are now 15 and were recently introduced by mutual friends.
Their biological parents say no-one told them they were having twins.
…
When they were introduced, they apparently burst into tears at the realisation that, looking so identical, they had to be twins.
I never thought “separated at birth” really happened. Odd.
Crudo, Italian Sashimi - Italian + Sashimi = Crudo, says David Pasternack. Hey Sagert, give this a try, won’t you?
Giraffe in my Loft - “There was a giraffe in my loft / I didn’t invite it / It was stomping ‘round for days / And kept me up all night.”
The Millwall Brick - Who knew newspapers could be weapons?
Amazing Grace - Why not watch Victor Wooten play Amazing Grace on a bass guitar, using only the harmonics of the instrument for the melody? Treeeemendous.
Great desks and productivity furniture - Really useful for sometime in the misty future - I especially like their basic computer desks.
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.
(thx, airbag)
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 UV DNA 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.
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