Hi,

I was just told that Cheryl Kemp had worked at Demeter bakery, Sydney,
Aus. It happens that I worked there as well(left Australia in 1992) -
what has happened with bakery and people involved with it? Anyone knows?

Regards

Zoran

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On
Behalf Of Allan Balliett
Sent: Thursday, January 16, 2003 6:16 PM
To: [EMAIL PROTECTED]
Subject: Conventional Science closes in on proving Sheldrake's theorem

>From today's Washington Post 
http://www.washingtonpost.com/wp-dyn/articles/A63146-2003Jan15.html

statement of interest: The more interesting implication of the study, 
he suggested, is that "there is a mechanism that preserves the 
genetic ability" to create wings, without becoming hopelessly 
corrupted through mutation.  "There must be something," Naskrecki 
said. "I just can't imagine what that mechanism would be."



Walking Sticks, Just Winging It
Insects' 'Re-Evolution' Challenges 'Use It or Lose It' Assumption of 
Evolutionary Biology

By Guy Gugliotta
Washington Post Staff Writer
Thursday, January 16, 2003; Page A03


A team of biologists says it has found what is quite likely the 
first-ever documented case of "re-evolution," suggesting that nature 
does indeed offer second chances -- a species can evolve a new 
characteristic, lose it and then regain it.

That's a radical idea, because for most of modern times, scientists 
have taught that evolution, at least in part, functions on the 
principle of "use it or lose it." This is one reason seals no longer 
have paws, moles see badly and humans lack heavy fur.

The team is challenging that assumption based on its analysis of DNA 
from 37 species of the insect order Phasmatodea -- commonly known as 
"walking sticks" -- which showed that they evolved from winged to 
wingless and back again. In fact, walking sticks made the shift four 
times.

The discovery calls into question one of the tenets of evolutionary 
biology: that if a species loses a complex characteristic, the gene 
or genes that express it will subsequently mutate so much that the 
function can never be recovered.

"We were shocked," said team leader Michael F. Whiting, an 
evolutionary biologist from Brigham Young University. "Even though 
there is no empirical evidence, it has been dogma for two centuries 
that something like flight requires so many complicated systems that 
it could only be evolved once, and would be very difficult to 
reinvent."

The study shows that "somehow this whole developmental problem can be 
switched on and switched off," said Pennsylvania State University 
biologist James Marden. "That's cool, and not just cool for insects. 
That's cool across the board."

Although walking sticks exist around the world, including in the 
Washington area, Whiting said he did most of his research in New 
Guinea, home to a large selection of the insects. Walking sticks 
number more than 3,200 species worldwide and come in both winged and 
wingless varieties.

They are big bugs. The smallest is about the size of a person's 
pinkie, while the largest -- about 18 inches long -- is the longest 
insect in the world. Walking sticks survive by using natural 
camouflage that makes them look like sticks, leaves, tree bark, 
shoots of grass or reeds. Whiting said the 18-inch walking stick 
hangs from a branch and sways like a dead stick.

The walking sticks' closest relative is the "web spinner," which 
sprays webs from its front feet -- like Spiderman. Other near 
relations include cockroaches, termites, mantises, grasshoppers and 
earwigs.

In its analysis, the team examined three genes from winged and 
wingless walking sticks. The analysis enabled the team to rank those 
species from most primitive to least primitive. The DNA from the most 
primitive species most closely matched that of the web spinners, 
pointing toward a common ancestor for both insects.

"The thought was that the insects that did not have wings were 
probably the most advanced," Whiting said. Insects can lose their 
wings for several reasons, he explained. For parasites, such as fleas 
or lice, wings are superfluous and awkward. And cold-weather insects 
shed their wings to decrease the surface area of their bodies.

For walking sticks, the theory held, being wingless meant that the 
females, at least, could devote greater energy to egg production. 
Also, while primitive walking sticks would have needed wings to get 
away from predators, more advanced species would have developed such 
good disguises that they would no longer need to fly.

The first surprise was that all of the most primitive walking sticks, 
unlike the web spinners next to them in the evolutionary tree, were 
wingless, Whiting said. Much further along, however, winged species 
reappeared. Subsequently, winged species disappeared and reappeared 
three more times.

"The inference is that the wingless ones evolved from a common 
ancestor that had wings," Whiting said. "The primitive species lost 
their wings, but 50 [million] to 100 million years later, more 
advanced species regained their wings." Whiting said walking sticks 
probably made their first appearance 300 million to 350 million years 
ago.

The findings did not come as a surprise to evolutionary biologist 
Piotr Naskrecki, of the nonprofit Conservation International. 
Naskrecki said he had observed similar behavior in other species and 
found it "very difficult to believe that this research is the first 
documented case of a complex feature being lost and recovered."

The more interesting implication of the study, he suggested, is that 
"there is a mechanism that preserves the genetic ability" to create 
wings, without becoming hopelessly corrupted through mutation.

"There must be something," Naskrecki said. "I just can't imagine what 
that mechanism would be."

Penn State's Marden suggested that the wing genes might avoid 
mutation if they were used for a related function. "Most of the genes 
involved in wing development are also involved in leg development," 
he said. Perhaps making legs kept the wing genes from atrophying, he 
said, enabling them to be summoned for a rerun 50 million years later.


C 2003 The Washington Post Company

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