The Utopian- A rEvolutionary Blog

In the halls of academia researchers are often more concerned about protecting their intellectual property than publishing the truth. Blogging offers a way to respect previous research, mine the information glut, and quickly publish the results. This blog is an experiment in gathering, documenting, associating, and presenting important information about human evolution using only a browser, the internet, and copy/paste techniques. These are not "my" words. I am only the editor.

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Location: United States

I have a BS degree in Wildlife from O.S.U. but most of my education comes from self study. I don't watch much TV because I don't think subjecting myself to all the materialistic and social propaganda is healthy. You can't view the world clearly if you put blinders on. My conclusions about the literature I cite on this website will be confined to the comments section. Please read those comments if you want to see the insights I have gained from my personal study. An interesting thing happened when I began this experiment. I discovered that bolding the important points of the research I was citing produced a rough summary of the information I could scan quickly, and also provided a easily referenced outline I could use to associate data from different sources using multiple browser windows. This led to a number of personal insights. Learning how to use blogs to data mine effectively can contribute greatly to the spread of global knowledge, and reduce the "information glut" that has accumulated.

Friday, February 18, 2005

Thoughts on the Origins of Bipedality

Bipedality, the ability to walk upright using only the lower limbs, is the most ancient of all characteristics that distinguish humans from apes. Bipedality deprives us of speed and agility and all but eliminates our ability to easily climb trees. We must propel our body with two limbs instead of four, and we are generally unable to use the hip and back as parts of our propulsive muscle system.

During its earliest evolution, bipedality is thought to have been a very costly form of locomotion. However, a reproductive advantage must have fallen to those in each generation that walked more frequently in a bipedal posture. Many theories have been developed to try and explain the evolutionary success of bipedality.

The main goals in any evolutionary game are to eat, stay alive, and reproduce. The edge was not speed because most four-legged animals move faster than humans. It was not efficiency because moving on two legs uses no more nor less energy than moving on four legs unless one is traveling a long distance. If this is the case, the number of calories that are expended for travel are lower in a biped than in a chimp walking on four legs or an antelope on four legs.

Even a rise of several degrees in body temperature, from 98.6° to 107° F, poses a special threat to the human brain, leading rapidly to convulsions, hallucinations, permanent neural damage, and sometimes death. Because of its large size, the brain itself generates lots of heat, which can accumulate to dangerous levels if not dissipated. Fortunately, like the engine of a car, the brain has a radiator to protect it from overheating - a network of tiny veins that originate in the scalp and face.

Unlike modern humans, apes lack a venous radiator. The evolution of bipedalism necessitated changes in blood circulation and may have laid the groundwork for its emergence. An examination of fossil skulls, however, reveals that a venous radiator did not arise immediately. It is absent in the earliest-known hominid (Australopithecus afarensis) and in some of its successors, the "robust" australopithecines. Brain size remained conservative in these species. But a prototype radiator is present in the "gracile" australopithecines. This is most evident in the greater number of holes in the skull, called emissary foramina, to accommodate emissary veins. I therefore conclude that the gracile australopithecines gave rise to our own genus.

Beginning about two million years ago, the number of emissary foramina in the genus Homo began to increase dramatically. Brain size also began to increase rapidly in this group, and these trends continued in tandem until the time of the Neanderthals (about 100,000 years ago). The evolving venous radiator apparently removed a major constraint on the increase of brain size.

Humans are not the only large-brained animals that evolved cranial radiators. Some fifty million years ago, the terrestrial ancestors of whales (including dolphins) began a major change in posture and locomotion that culminated in their becoming exclusively adapted to an aquatic habitat. Like humans, whales have evolved large, highly convoluted brains that generate potentially damaging heat.

Hominids, or humanlike primates, first appeared in Africa five to seven million years ago, when that continent's climate was becoming increasingly arid and large tracts of woodland and savanna were replacing the unbroken canopy of the equatorial forest. While the ancestors of chimpanzees and gorillas remained in the moist forests, the hominids started to exploit the more open, drier habitats. The intense sunshine in the new environment, combined with a scarcity of drinking water, must have severely challenged the ability of early hominids to regulate their body temperature.

Most savanna mammals possess special physiological mechanisms to cool the brain - notably the carotid rete, a network of fine arteries near the base of the brain, coupled with venous circulation through the muzzle. Humans, apes, and monkeys, however, lack these features. The first hominids could have prevented damaging elevations of brain temperature only by keeping their entire body cool. Walking on two feet - the unique mode of terrestrial locomotion that is widely recognized as the first key development in hominid evolution - conferred precisely these benefits.

Bipedalism dramatically reduces exposure to direct solar radiation during the middle of the equatorial day. Bipedalism also raises most of the body well above the ground, so that the skin contacts cooler and faster-moving air currents. This favors heat dissipation through convection.

Scientists have long reasoned that one of the most obvious and unusual human features, the loss of insulating body hair, is an adaptation to the hot savanna. Although follicles are still densely distributed over most of the human body, the hairs they produce are so short and fine that the underlying skin is exposed directly to the flow of air, promoting the shedding of excess heat by convection. The problem with this hypothesis has always been explaining why humans differ from other savanna mammals, which have retained dense coats of hair.

In environments where mammals are exposed to strong solar radiation, the coat acts as a shield, reflecting and reradiating heat before it reaches the skin. For most mammals, the loss of this insulation would create more problems that it would solve. For a biped, in contrast, a naked skin saves water because so little skin surface is exposed to the sun. Mainly the head and upper shoulders are exposed, and these can be protected by the retention of a relatively small amount of hair cover. Bipedalism and the strategy of cooling the whole body (rather than just the brain) probably explain why humans evolved a naked skin, while other savanna mammals of comparable size did not.

4 Comments:

Blogger The Utopian said...

Comparing this author's research with the "Wading for food" research on bipedalism, illustrates the complex way different physical and social adaptations work together to produce even more advanced physical and social changes, and this is precisely what the authors of shift theory conclude with the concept of "meta-evolution".

We are constantly changing the conditions for our own evolution, and at some point we will realize socially that we are in the process of assuming conscious control of our evolutionary future. More importantly this will happen wheather we want it to or not!

We cannot stop the increase of knowledge that has begun, and we dare not try to stop the conscious control of our evolution. Passing moral laws will not stop all people from genetic and social experiments. The best we can do is try to influence the direction we want these experiments to lead us.

Forbidding people to experiment will only force those experiments underground, where they are more likely to be done by those with lower moral standards. Thus we must boldly face the challenge and make intelligence and wise choices for the directions we want humanity to pursue. "Where there is no vision, the people will perish".

1:36 PM  
Blogger Mr_Proteus said...

Forbidding people to experiment will only force those experiments underground...Or overseas. At one time I would have thought we should ban certain experiments until we understand them better. However, the world has caught up and in some cases surpassed our scientific progress, and many countries have no taboos about the limits of science.

We have to strive forward, get this information out to the public so we can be aware of our new capabilities and build "safety nets" to manage our growth.

Of course, inevitably will come the day of exponential growth of knowledge, where even our top scientists will not be able to keep up with the pace of scientific discovery.

I quite agree with your assessment of our future. It's requires more than just one genius in his ivory tower steering humanity's course, it will require a large number of people with the vision and compulsion to steer the course, and hope the masses will follow. As a species, we are still in our infancy.

Keep blogging!

7:50 PM  
Blogger The Utopian said...

Thank you for reading and posting on this blog Mr. Proteus. I am hoping many others will take advantage of the important information I am gathering and condensing to help spread this knowledge globally.

Before we can actively partake in our human evolution, we must educate ourselves about our evolutionary past and also determine what paths are available for our future.

We already have a vast amount of scientific research that needs to be processed and correlated using multdisciplinary effort. Unfortunately, much of that research is not available to everyone. The internet is changing that however, as more research is published on-line.

The issue of intellectual property rights must also be re-evaluated if we truely want to spread knowledge and educate the mass of humanity.

There is a collective unconscious that exists in the ever-present "now" which contains all knowledge. Bringing a piece of that knowledge to our conscious attention should not give anyone exclusive ownership of that knowledge. That is a materialistic concept that is misplaced in the subjective world of intellect and knowledge.

Knowledge is a shared public resource and must be accessible to everyone, only limited by our individual ability to comprehend it.

10:30 AM  
Anonymous Anonymous said...

Sometimes, these gambles pay off, but there are occasions when they fail miserably,

2:08 AM  

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