Dear Family & Friends,
Last year I wrote a posting with our Tanzanian friend Moris about his daily routine. He recently lost a very large chunk of his income. Diane and I continue to hire him for food shopping and other errands every week, but it's not really enough. So Moris is casting about for other ways to earn some money.
He has friends who are local artists and has arranged to get a cut of the selling price if he is able to find buyers for their work. I have agreed to display some of the pieces on this blog and to handle the money if anyone out there would like to make a purchase.
The artwork is pictured below. If you would like to order something, send me an email. Please keep in mind that postal service between Tanzania and the U.S. is sl-o-o-o-w. Also, our Internet access goes out on occasion, I'm busy as a secondary school teacher -- and a lot of things just happen more slowly in this part of the world. 8-D
Pictured above are four greeting cards, completely blank on the inside and on the back. Each card is roughly 4" by 6". (If you are familiar with European measures each card is a sheet of A5 paper folder in half.) I especially like Card A, which is done in the tinga-tinga style. Each card is $2.50, which includes postage, etc.
Pictured above are two small paintings. Painting A is about 4" by 5" at its widest and tallest points. Painting B is about 4.5" by 7.5". They are done on 1/8" masonite board. Painting A is $4 and Painting B is $6.
Again, send me an email directly if you would like to make a purchase so that we can arrange for payment (PayPal or otherwise) and address to ship to. -Earl
Sunday, February 27, 2011
Wednesday, February 16, 2011
Our Cooling System
As I sit at home in Mtwara sweltering in the heat and humidity with nothing on but underwear and sandals and with an electric fan blowing on me, I try to take comfort from the fact that we human beings have a whole-body cooling system that is far more efficient than that of any other mammal.
The book AFRICA: A Biography of the Continent has a very interesting chapter on this. Our upright stance may have come about as a way to reduce the amount of body surface that is directly exposed to the sun during the hottest part of the day. Being off the ground also puts us up into air that is windier, cooler, and less humid compared to a quadraped.
The other component is well-developed sweat glands together with bare skin. Actually, we have as many hairs per unit area of skin as a chimpanzee -- but those hairs are mostly so fine that we are functionally naked. As a result sweating is an extremely effective way of removing heat from the body as the sweat evaporates.
Here in East Africa being able to stay cooler and more active allows humans to reduce their water requirements and be able to forage farther for food in the open savanna. This would have been the immediate advantage.
But the longer term consequence might have been that this unique system removed a physiological constraint on the development of a large brain! Brain tissue is expensive in terms of its continuous need for oxygen, fuel, and a narrow temperature range in which to operate. The brain runs hot. A researcher is quoted: "it is probably no coincidence that today the mammal with the most highly developed brain and social behavior is the species which possesses the most elaborate cooling system".
If we had not evolved a body that is so good at staying cool I might not now be expressing myself in such an intricate language as an act of a shared complex culture and doing so on a machine. 8-D
- Earl
The book AFRICA: A Biography of the Continent has a very interesting chapter on this. Our upright stance may have come about as a way to reduce the amount of body surface that is directly exposed to the sun during the hottest part of the day. Being off the ground also puts us up into air that is windier, cooler, and less humid compared to a quadraped.
The other component is well-developed sweat glands together with bare skin. Actually, we have as many hairs per unit area of skin as a chimpanzee -- but those hairs are mostly so fine that we are functionally naked. As a result sweating is an extremely effective way of removing heat from the body as the sweat evaporates.
Here in East Africa being able to stay cooler and more active allows humans to reduce their water requirements and be able to forage farther for food in the open savanna. This would have been the immediate advantage.
But the longer term consequence might have been that this unique system removed a physiological constraint on the development of a large brain! Brain tissue is expensive in terms of its continuous need for oxygen, fuel, and a narrow temperature range in which to operate. The brain runs hot. A researcher is quoted: "it is probably no coincidence that today the mammal with the most highly developed brain and social behavior is the species which possesses the most elaborate cooling system".
If we had not evolved a body that is so good at staying cool I might not now be expressing myself in such an intricate language as an act of a shared complex culture and doing so on a machine. 8-D
- Earl
Sunday, February 6, 2011
"AFRICA: A Biography of the Continent"
"About 100,000 years ago groups of modern humans left Africa for the first time and progressively colonized the rest of the world. Innovative talent carried them into every exploitable niche. They moved across the Sinai peninsula and were living in the eastern Mediterranean ...
By the early 1970s people had been to the moon. Such achievements, and all by virtue of talents which had evolved in Africa."
- from AFRICA: A Biography of the Continent, by John Reader
We all came out of Africa. Many of the most important fossil finds of early people have occurred here in Tanzania and nearby. I feel like I have returned to the cradle of humankind.
This book has impressed on me the extent of my ignorance of this huge sub-Saharan continent from which my ancestors left relatively recently, in evolutionary terms.
The writing is lucid, well-researched, compelling, and easy to read. The content is vast, addressing topics such as the ability to make a tool according to a mental picture; the development of language; the effects of geology, climate change, and diseases; the beginnings of agriculture; early cities and civilizations; the deep and widespread social disruptions caused by slavery and the slave trade; and the codifying of culture into rigid ethnic categories as an invention of Europeans.
There's much more, and it's highly recommended. -Earl
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