Received: by alpheratz.cpm.aca.mmu.ac.uk id VAA10632 (8.6.9/5.3[ref pg@gmsl.co.uk] for cpm.aca.mmu.ac.uk from fmb-majordomo@mmu.ac.uk); Wed, 15 May 2002 21:50:03 +0100 X-Originating-IP: [67.243.218.243] From: "Grant Callaghan" <grantc4@hotmail.com> To: memetics@mmu.ac.uk Subject: RE: Memetic Influence on Evolution Date: Wed, 15 May 2002 13:43:46 -0700 Content-Type: text/plain; format=flowed Message-ID: <LAW2-F132f3sllNY30k0001a3f8@hotmail.com> X-OriginalArrivalTime: 15 May 2002 20:43:46.0476 (UTC) FILETIME=[35978EC0:01C1FC51] Sender: fmb-majordomo@mmu.ac.uk Precedence: bulk Reply-To: memetics@mmu.ac.uk
>Subject: RE: Memetic Influence on Evolution
>Date: Wed, 15 May 2002 16:55:28 +0100
>
>Hi Lawrence,
>
> > Date: Tue, 14 May 2002 18:23:39 -0400
> > From: "Lawrence DeBivort" <debivort@umd5.umd.edu>
> > Subject: RE: Memetic Influence on Evolution
> >
> > Greetings, all,
> >
> > If it is unclear today to what extent memes influence biological
>evolution,
> > the answer will become increasingly clear in the coming years and
>decades,
> > not longer. One of the salient characteristics of our age is
>evolutionary
> > development -- our growing ability to manage our own evolution, and we
>do so
> > in all instances through our initial exchange of memes, and the
>emergence of
> > some over others.
> >
> > Steve, can you explain a bit more what you mean by 'coarser'? Thanks.
> >
> > Lawrence
>
>Memes do have some influence on our evolution which was the coarser bit I
>referred to. We can select for sex early enough to decide whether to
>terminate or not (its is banned in my health authority), or for Down's
>children.
>
>Sex selection has already distorted the ratio of male to female in the
>younger generation in China, resulting in a distinct 'surplus' of males.
>How
>this will translate in social terms is any ones guess. Carried to it's
>illogical conclusion, we could easily choose our self out of existance :-)
>
>However, in general, these effects, if any, on human evolution would take
>far longer than our life span to manifest.
>
>Regards
>
>Steve
>
IMO advances like the following are going to make it happen much more
quickly.
Grant
DNA nanoballs boost gene therapy
10:00 12 May 02
Exclusive from New Scientist Print Edition
Scrunching up DNA into ultra-tiny balls could be the key to making gene
therapy safer and more efficient. The technique is now being tested on
people with cystic fibrosis.
So far, modified viruses have proved to be the most efficient way of
delivering DNA to cells to make up for genetic faults. But viruses cannot be
given to the same person time after time because the immune system starts
attacking them. Viruses can also cause severe reactions.
As a result, researchers increasingly favour other means of delivering
genes, such as encasing DNA in fatty globules called liposomes that can pass
through the membranes round cells. But simply getting a gene into a cell is
not enough - for the desired protein to be produced, you need to get the
gene into the cell's nucleus.
At around 100 nanometres in size, most liposomes are too large to pass
through the tiny pores in the nuclear membrane except when the membrane
breaks down during cell division. Even if cells are rapidly dividing,
delivering genes via liposomes is not very efficient - and it is no good for
slowly dividing cells such as those lining the lungs.
But researchers at Case Western Reserve University and Copernicus
Therapeutics, both in Cleveland, Ohio, have developed a way to pack DNA into
particles 25 nanometres across, small enough to enter the nuclear pores.
6000-fold increase
The nanoparticles consist of a single DNA molecule encased in positively
charged peptides and are themselves delivered to cells via liposomes. In
cells grown in culture, there was a 6000-fold increase in the expression of
a gene packaged this way compared with unpackaged DNA in liposomes.
Trials have now begun in 12 people with cystic fibrosis, who have a faulty
gene that means thick mucus accumulates in their lungs. The researchers will
first test the technique on nasal cells before trying to deliver genes to
the lungs.
"We're very excited about this," says Robert Beall, president of the Cystic
Fibrosis Foundation. "Everybody recognises that gene therapy could provide
the cure for cystic fibrosis, and it is exciting that this is a non-viral
approach."
No immune reaction
When Pam Davis of Case Western University School of Medicine tried the
technique on mice with cystic fibrosis, she found the replacement gene was
expressed in nasal lining and partially restored function - with little or
no immune reaction. But that does not mean the method will work in people,
she warns, because mice have a very different airway structure.
Indeed, there have already been many failed attempts to treat cystic
fibrosis with gene therapy. Lungs are especially challenging, says
respiratory specialist Duncan Geddes of Imperial College, London, because
the lung lining is designed to keep out foreign objects. The build-up of
thick sputum in the lungs of cystic fibrosis patients makes the problem even
worse.
But the replacement gene only needs to be expressed in a small proportion of
cells, Geddes says. "It's extremely interesting and promising."
Sylvia Pagán Westphal, Boston
For more exclusive news and expert analysis every week subscribe to New
Scientist print edition.
Even if the cystic fibrosis experiment fails to work because of the mucus
problem, the fact that they can deliver specific genes to the nucleus of a
cell and have it produce a 6000 fold increase in expression means there is
the potential of a quantum jump in our ability to make changes in the
expression of certain human genetic traits.
What we will do with this newfound power is uncertain, but the size of the
nanoballs and our ability to make them in quantity means we could dispense
them like candy and make wholesale changes to populations of plants, animals
and people. The article doesn't say if these changes will be heritable --
but it doesn't matter much if individuals can me changed on a grand scale
with manufactured ingredients. It will be a lot like the current use of
antibiotics on chickens and cattle, which is having an affect on our ability
to fight diseasees such as staphococus -- an unintended memetic consequence
that has caused genetic changes in bacteria and is now making itself felt in
hospitals around the world.
Grant
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