Doug Henwood wrote:
On Dec 12, 2006, at 12:46 PM, Jim Devine wrote:
while looking for a quote to replace Brecht (see below), I found the
following attributed to Marx: "Sell a man a fish, he eats for a day,
teach a man how to fish, you ruin a wonderful business opportunity."
.
Groucho Marx?
.
Hmm. Seen on a bumpersticker in the failing fishing town of
Gloucester, Mass.: "Give a man a fish and he eats. Teach a man to
fish and he starves."
Doug
.
But if he lived in California and possesses a commercial fishing
license, there'd be a 1-in-3.33 chance that the feds would pay $100,000
to buy him out.
The federal government is covertly buying out 1/3 of California's
fishing fleet because, quite simply, 90% of the "food fish" for humans
have taken a vacation from the planet and they aren't coming back
anytime soon. Must maintain markets into a dwindling supply and rising
demand (population growth, not to mention sushi bars!).
It will be good practice for "oil crunch" times coming up.
Soy(lent) protein anyone?
Less vitamin E in the diet?
Don't worry, we'll adapt nutritionally over the next millenium or so.
(to the smoke from peat-fired centralized energy sources too!).
Leigh
December 10, 2006
Study Detects Recent Instance of Human Evolution
http://www.nytimes.com/2006/12/10/science/10cnd-evolve.html
By NICHOLAS WADE
A surprisingly recent instance of human evolution has been detected
among the peoples of East Africa. It is the ability to digest milk in
adulthood, conferred by genetic changes that occurred as recently as
3,000 years ago, a team of geneticists has found.
The finding is a striking example of a cultural practice — the raising
of dairy cattle — feeding back into the human genome. It also seems to
be one of the first instances of convergent human evolution to be
documented at the genetic level. Convergent evolution refers to two or
more populations acquiring the same trait independently.
Throughout most of human history, the ability to digest lactose, the
principal sugar of milk, has been switched off after weaning because
there is no further need for the lactase enzyme that breaks the sugar
apart. But when cattle were first domesticated 9,000 years ago and
people later started to consume their milk as well as their meat,
natural selection would have favored anyone with a mutation that kept
the lactase gene switched on.
Such a mutation is known to have arisen among an early cattle-raising
people, the Funnel Beaker culture, which flourished some 5,000 to 6,000
years ago in north-central Europe. People with a persistently active
lactase gene have no problem digesting milk and are said to be lactose
tolerant.
Almost all Dutch people and 99 percent of Swedes are lactose-tolerant,
but the mutation becomes progressively less common in Europeans who live
at increasing distance from the ancient Funnel Beaker region.
Geneticists wondered if the lactose tolerance mutation in Europeans,
first identified in 2002, had arisen among pastoral peoples elsewhere.
But it seemed to be largely absent from Africa, even though pastoral
peoples there generally have some degree of tolerance.
A research team led by Sarah Tishkoff of the University of Maryland has
now resolved much of the puzzle. After testing for lactose tolerance and
genetic makeup among 43 ethnic groups of East Africa, she and her
colleagues have found three new mutations, all independent of each other
and of the European mutation, which keep the lactase gene permanently
switched on.
The principal mutation, found among Nilo-Saharan-speaking ethnic groups
of Kenya and Tanzania, arose 2,700 to 6,800 years ago, according to
genetic estimates, Dr. Tishkoff’s group is to report in the journal
Nature Genetics on Monday. This fits well with archaeological evidence
suggesting that pastoral peoples from the north reached northern Kenya
about 4,500 years ago and southern Kenya and Tanzania 3,300 years ago.
Two other mutations were found, among the Beja people of northeastern
Sudan and tribes of the same language family, Afro-Asiatic, in northern
Kenya.
Genetic evidence shows that the mutations conferred an enormous
selective advantage on their owners, enabling them to leave almost 10
times as many descendants as people without them. The mutations have
created “one of the strongest genetic signatures of natural selection
yet reported in humans,” the researchers write.
The survival advantage was so powerful perhaps because those with the
mutations not only gained extra energy from lactose but also, in drought
conditions, would have benefited from the water in milk. People who were
lactose-intolerant could have risked losing water from diarrhea, Dr.
Tishkoff said.
Diane Gifford-Gonzalez, an archaeologist at the University of
California, Santa Cruz, said the new findings were “very exciting”
because they “showed the speed with which a genetic mutation can be
favored under conditions of strong natural selection, demonstrating the
possible rate of evolutionary change in humans.”
The genetic data fitted in well, she said, with archaeological and
linguistic evidence about the spread of pastoralism in Africa. The first
clear evidence of cattle in Africa is from a site 8,000 years old in
northwestern Sudan. Cattle there were domesticated independently from
two other domestications, in the Near East and the Indus valley of India.
<...>
More:
http://www.nytimes.com/2006/12/10/science/10cnd-evolve.html?_r=1&oref=slogin
