August 26, 2007

What are we all?

We're part of life on Earth. What life on Earth really is, how new species arise, we don't really know. Random mutation and natural selection doesn't explain it, it just restates the problem of what life is at another level of detail. What is really random and where does randomness come from? That's a deep problem for the philosophy of life and existence. If mutations are random how do they end up so often when and where needed and not very often at other times? That's a problem to keep at least geneticists busy for a long time, if the answer doesn't lie somewhere beyond their specialty. How is "natural selection" different from "what survives, survives," a redundancy?

At least we know we're part of life on Earth. We're just like any other land mammal, except for our behavior. We're adapted to the Earth's atmosphere, gravity, Earth foods, Earth bacteria. There are skeletons of presumable human ancestors who lived about any number of years ago you care to name. Not a skeleton for every year, but enough to fill a picture with links including some extra links that probably aren't ancestors. Within the last 12,000 years, the skeletons are supposed to be about the same anywhere as up to 1492. For skeletons that are believed to be about 40,000 years old, the ones in Europe that looked less like ancestors of anyone were called Neanderthal, and the ones that looked a lot like local ancestors were called Cro Magnon. Since that terminology was vague and misleading for human remains outside Europe, finds that would have been called Cro Magnon are now called "anatomically modern humans" as the preferred terminology. If anatomically modern humans weren't our direct ancestors, then who was?

The story scientists are telling now is that about 100,000 years ago, in East Africa some hominids who were already pretty much anatomically modern humans began spreading out over the whole world, and also became human in behavior, at least as far as painting with ocher and making figurines and other things archaeologists can detect that are beyond just making one kind of sharpened stone by habit. But the alternate story that there was some mixing of regional varieties with a spreading group of humans with modern behavior still has some life in it, because science always has new measurements and hypotheses. Maybe there was a bottleneck roughly 100,000 years ago in terms all human ancestors, then those spread out, then roughly 50,000 years ago behaviorly modern humans arose, and spread out and mixed with the earlier wave, but that spreading and genes for intelligence becoming predominant is not yet complete.

Why hominids split from apes and when is a totally separate range of prehistory problem, whatever you believe about the accuracy of various forms of radiological dating. Of course there are still apes, there are still jungles for them to live in and stay safe by climbing trees, where modern humans are in danger from predators because it's harder for us to climb trees, being adapted so well to walking upright since Australopithecines, which they say lived 4 to 6 million years ago. If it weren't for apes, it would be some other distant relative of humans that creationists would ask their question about. Why are there still cows, if humans and cows share a primitive mammalian ancestor? Why are there still flies? Why are there still rocks? If life evolved and humans are the superior product of evolution, then everything in the universe should be humans, nothing else remaining, according to creationist logic.

Now scientists are saying there are a few more million years to wonder about between Australopithecines and a common ancestor of apes and humans. I think that could be the time in which the pre-hominids developed from forest apes to all the adaptations to walking upright that we have. I tend not to believe that random point mutations and selection can explain major changes in species like that, because if you look at the genetic differences between humans and chimpanzees, there are entire chromosome reorganizations. Truly distinct species are unable to produce fertile offspring together, due to chromosome set differences, which implies for every species there was a bottleneck of one lucky complete mutant as the founding mother or father of the whole species, and since it's so hard to breed successfully with chromosome differences, a lucky breeding incident of that mutant and the previous normals, or else parthenogenesis.

As for humans having 26 hour biological clocks, I think the deeper physiological clock of humans that regulates heat has been shown to run at about 24 hours, but the sleep clock runs at about 25 or 26 hours when humans are separated from natural cycles of sunlight and dark. That's a good thing, because it allows rotating your sleep to adjust to the seasons and changes of what parts of the day are good for activities and for sleeping, and it may allow a hunter or scavenger to make use of moonlight, following the almost 25 hour cycle of when the moon is up.

The Garden of Eden is an allegory for something that really happened: Humans started judging what was good to eat for themselves, and invented agriculture, instead of just eating the easy and appetizing fruit and nuts and meat that don't have to be cooked to be edible. That choice condemned their descendants to earning their bread by the sweat of their brows, as it is written.

[I wrote this as a comment to a post at Vault-Co. It stands well enough on its own as a sample of where my thoughts on human evolution are.]

August 19, 2007

Bicycling going well

I've bicycled 19 days in a row, and I'm starting to feel better and getting better at it.

I rode about 8 miles yesterday, while the weather was sprinkling and it was dark. Today I rode the same a little earlier so I had some light, and I don't feel tired, I feel energized.

I've been averaging about 12 mph for entire rides, including stops, which is supposed to be typical for casual bicyclists (as opposed to cyclists, competitors in the sport of cycling.) I don't keep track precisely of how fast or have a speedometer or bike computer, because that would defeat the purpose of getting out there and letting out energy freely and losing track of time. I blow past some more casual bicyclists despite myself. Since I'm up to using gear ratios of 2 or more through the whole ride including uphills and I'm increasing my cadence along with that, I might get fast enough to keep up with some amateur cyclists, just based on my natural level of enjoying physical exertion.

Exercise literally means "driving out" as in driving animals out of an enclosure to let them have their necessary physical activity. When I studied that and decided to believe it works that way - that you just get out there, then do as much as you like - then it became easy. I just make sure to get out on the bike at all every day, and the rest comes naturally.

August 05, 2007

Starting Bicycling Every Day

I'm on my fifth day of biking every day.

I decided at the end of July to start at the beginning of August so that it would be easy to count how many days I've biked, to keep up my resolution. I thought of starting this for several months this year, thinking of how to slide into it easily. Then I realized the months were slipping by without my starting it, and the summer when it's easier to start was slipping by. Conclusion: Start whether it seems easy or not, like my life depends on it. I'll figure out whether it was exactly the right decision later on, instead of letting that worry prevent me from starting when it will very likely be a good decision in hindsight.

An interesting incident from the second day:

I went too many miles too fast, because I was excited by exploring a new bike path and didn't want to wait until I was in shape to go that far. I thought I "bonked" on the way back. The "bonk" may have been a combination of a number of types of exhaustion: dehydration, hypothermia* from having clothes wet with sweat as the day cooled into evening, low blood sugar, out-of-breath**, sore muscles, and sleepiness. The overall effect was that my pedaling was not just weak as in normal tiring, I started feeling like maybe I should just take up walking instead of biking. I felt a desire to sit down and rest at the very next park bench by the path.

When I sat down, my perception of the situation went from a narrow focus on getting somewhere, to realizing how incredibly tired I was and how much I needed to rest and to catch my breath, to resting and taking in some calm, to waking up to the need to get home and my sensitivity to perception and awareness being enhanced. Except my ability to bike wasn't enhanced. I felt weak enough that I didn't pedal at all downhill, and discovered more subtle downhills than I was aware of on previous rides. When I did try to pedal it was like going weak in the knees, not being able to put much force in, and although I didn't feel dizzy, when I went over bumps the bike shook almost out of control. Because of those effects, I walked up every hill and across every road crossing for the rest of the way back, more like stumbling, for safety's sake, not knowing how much more damage I might do to myself in that unusual state. Plus it was dark, since the ride was taking a lot longer than I had planned.

And yet, I liked the experience overall, for the effect of enhancement of perception and enjoyment, which continued for a couple of hours afterwards.

What I learned from the fifth day:

Even if your muscles are sore, that does not mean you can't get out there and bike a useful amount. When I'd had sort legs all day and felt sure it wouldn't be a good idea to go very far, I was able to go a mile away easily, and come back with plenty of energy. The spinning seemed to work the soreness out of my legs by increasing the circulation, so my legs weren't sore afterwards.

In conclusion: Why biking?

The overall reason for biking although it isn't natural, is that civilization judges us for whether we walk or run (or stand or sit) and makes it difficult physically, with pavements and traffic, to choose walking or running by instinct. Bicycling lets a body get out there and let loose any amount of energy it feels like, whether it would count as walking or jogging or sprinting uphill if on foot. You can't tell very well how much energy you're putting into it, unless you have a bike computer that measures that, because even if you can estimate how fast you're pedaling and with how much force, to multiply to estimate power, those quantities are constantly changing, and your perception of them changes as you get excited or tired. It's a good thing that you can't tell how much energy, because it lets you just take out energy that's otherwise pent up in the constraints and self-consciousness of civilization. Taking out energy as your body desires helps your whole nervous and physical system adapt better to living.


Notes added August 8:

* Instead of hypothermia, I may have experienced increased core temperature, which sports medicine says may lead to muscle relaxation and changes in neurotransmitters. (See Runner's High: Is It for Real? at MedicineNet.com and 20 Proven Health Benefits of Exercise at Health24.com, benefit number 5: Exercise is an excellent de-stressor.)

** Instead of out-of-breath, I may have experienced hyperventilation, because of breathing more in anticipation of out-of-breath.