Letters : Is human tissue safe?
Ottawa, Canada
Your editorial “The means to an end”, supporting the replacement of rodent
tissues with human tissues for most laboratory experiments, ignores important
issues of biosafety (Editorial, 25 October, p 3).
Tissues from purpose-bred rodents are essentially free of viruses that infect
for humans, the same is obviously not true for primary human tissues from
hospital repositories. Frankly, the thought of the latter tissues gaining
wide-spread use in ill-equipped laboratories staffed with inadequately trained
personnel frightens me more than any issues of biosafety raised by
xenotransplantation. Your wholehearted backing for this approach would seem to
be premature.
Letters : . . . . .
Barnard Castle, Co Durham
By a simpler version of Gott’s argument, whenever he visits a building there
is a 50 per cent probability that his visit occurs during the second half of the
building’s lifetime. So it is fortunate that he was not around to visit
Westminster Abbey or St Paul’s Cathedral shortly after they were built.
The fallacy of the argument, of course, lies in confusing the ensemble over
which the probability is applied. It may be true that, of all the visits people
make to St Paul’s, half will lie within the second half of its lifetime. But it
does not follow that, of all the buildings visited by Gott, half will be visited
during the second half of their lives.
Letters : Are we doomed?
J. Richard Gott III paints a worrying picture for the future of humanity: a
mere 8 million years to go
(“A grim reckoning”, 15 November, p 36).
However, the future may be even more bleak than his article suggests.
His article could not have been published at any other stage within the 200
000 years of Homo sapiens’s existence, as it requires a level of
statistical and probabilistic reasoning that has only been around for 100 years.
Gott’s random visit is not simply during the existence of humanity, but during
the existence of probability theory. Using his calculations, this means the
future for probability as a discipline has only somewhere between 2.5 years and
3900 years to go.
The prudent statistician ought to learn a different trade before the year
2000. Furthermore, it is hard to imagine a technological society without
statistics, so technological collapse is inevitable before the end of the 6th
millennium.
There is some light on the horizon. Gott’s reasoning depends on a random
visit within the duration of a phenomenon. However, unlike Gott’s visit to the
Berlin Wall, which we can assume was independent of subsequent political events,
there is an intimate link between the phenomenon of human history and Gott’s
observations about it.
Assuming Nature’s referees have done their job well, Gott’s 1993
paper is the first published recognition of a Copernican principle of events. It
is therefore not a random point within the lifetime of Homo sapiens but
the first of a particular kind of event within that lifetime. In this case it is
like predicting the longevity of a marriage, not from a random visit, but from
the time between the ceremony and the first argument. Happily, more than 2.5 per
cent of marriages last far longer than 39 arguments.
Letters : Jeans to dye for
huge@axalotl.demon.co.uk
If jeans are indeed dyed with indigo made by transgenic E. coli
(Inside Science, 15 November), should they be called gene jeans? And was that
what David Bowie was singing about?
Letters : Fingering Scruggs
Your article suggests that banjo players can sound like Earl Scruggs by using
a new bronze alloy tone ring
(This Week, 8 November, p 28).
Alas, if only it were true. Scruggs’s unique sound wasn’t due to the pre-war
tone ring in his banjo (which many other 1920s and 1930s banjo players were also
using) it was because he developed and perfected a three-finger picking
technique that many banjo players try to emulate but few even come close to.
The sound Scruggs got out of a banjo was due to an extraordinary talent that
defies scientific description. To attribute it to a “special alloy” is ridiculous.
Letters : Living test tubes
Hitchin, Hertfordshire
Your article on “antibody cruelty”, including a quote attributed to me,
contains some unfortunate wording which might create the wrong impression about
the Dr Hadwen Trust
(This Week, 15 November, p 12).
I would like to make it clear that the trust certainly does not underestimate
the suffering and loss of life involved in using animals as living test tubes
for antibody production. Indeed, the trust is based on antivivisection
principles which are as strong today as they were in 1970, when it was
established to develop alternatives to animal experiments.
The Dr Hadwen Trust welcomes the government’s new commitment to phase out
monoclonal antibody production in animals. We will be encouraging them to do
this as speedily and effectively as possible, so that animals will no longer
have to endure the pain and distress of this procedure.
Letters : Feel the width
Geelong, Australia
Unfortunately, your article’s explanantion of why some wool products “itch”
is incorrect
(This Week, 25 October, p 7).
The “itch” or skin comfort of wool garments has been the subject of an
extensive research programme at CSIRO, supported by Australian woolgrowers’ funds.
If samples of wool and acrylic鈥攚hich are chemically quite
different鈥攁re matched in terms of the fibre diameter and fibre mechanical
properties, then the two fabrics give the same level of skin comfort. Acrylic
fibres have a smooth cylindrical surface, unlike the characteristic wool scale
structure claimed in the article to be central to the sensation. The underlying
mechanism is related to the mechanical properties of fibres and not the fibre
type, chemical composition or detailed surface morphology.
The diameter of the individual fibres in any wool sample is quite variable,
typically 10 to 40 micrometres for apparel wools. After manufacture into a
garment, some wool fibre ends always protrude above the fabric surface and can
press against the skin during wear. These fibre ends will bend or buckle if the
applied load exceeds a critical value. This maximum force is highly dependent on
the fibre diameter.
The thin protruding wool fibre ends simply bend or buckle under the forces
applied by the clothing, whereas the thicker fibre ends, typically those thicker
than about 30 micrometres, are able to “push” hard enough against the skin to
trigger nerve endings lying just below the skin surface. Too many triggered
nerve endings in a local area of the skin are interpreted in the brain as the
unpleasant sensation referred to as “itch”. Thus the sensation has a purely
mechanical origin and is not in any way a chemical or allergenic response.
Different wool qualities contain different mixtures of coarse and fine
fibres. Discomfort only arises when coarser wool qualities are inappropriately
used in next-to-skin garments.
This CSIRO research has led to two new retail sub-brands “merino extrafine
wool” and “pure merino wool” for the familiar Woolmark symbol. These sub-brands,
based on wool fibre diameter criteria, identify consumer garments made from
appropriate wools for next-to-skin comfort.
Letters : . . . . .
Nairobi, Kenya
In addition to developing a sustainable land-use strategy, fire management
policy and high-quality, policy-orientated, scientific research, it is vital to
include a strategy for agricultural development. We in the International Centre
for Research in Agroforestry (ICRAF) are helping the Indonesian government to
achieve this aim.
In 1994, the Consultative Group on International Agricultural Research chose
the “alternatives to slash-and-burn” (ASB) programme as one of its first global
initiatives. The aim of the ASB programme is to improve farmers’ welfare and
protect the environment by developing land-use practices and policies that offer
farmers sustainable and profitable alternatives to the slash-and-burn form of
shifting cultivation. Agroforests and community forests are two good examples of
viable alternatives.
The ASB programme is conducted in three regions鈥擲outheast Asia, Latin
America and West Africa.
Letters : Fire fighting
Cairns, Queensland
Nick Mawdsley implies that the Indonesian government does not understand the
risks and costs of its policies, and needs an effective land-use policy,
including a strong fire-management policy
(Forum, 25 October, p 51).
The evidence is that the government knows exactly what it is
doing鈥攎aking money. Moreover, it already has policies on land use, fire
management, rural poverty, land tenure and economics. It just doesn’t
necessarily implement these.
Jakarta and Bogor are full of foreigners telling the locals what to do.
Perhaps Mawdsley, as a British Council consultant in Jakarta, will be the one to
bend the president’s ear. But if he really wants to do something for the
Indonesian people and their environment, he would be well-advised to step
outside the government arena and work with the major grassroots nonpolitical
organisations in Indonesia, which have highly educated staff, can force changes
in government policy simply by virtue of their size, and have the networks to
allow environmental education of the public.
Letters : . . . . .
Torquay, Devon
Reading Gott’s article was, for me, a revelation. The insidious
anthropomorphism that pervades us all was for once temporarily expunged from my
mind. I was shamed to realise that I had unwittingly committed the same error as
Copernicus’s contemporaries and arrogantly regarded “my time” as “the time”, as
if no other time mattered. The link Gott has established between past, present
and future excites me, though I do not believe this was fully developed in the
article.
My mind rushed with the anecdotal link to relativistic and quantum causality
and whether the empirical application of statistics to the time line described
by Gott can be used analytically in those fields.
Letters : They're taking over
Teignmouth, Devon
The possibility of independent “artificial” evolution raised in “Creatures
from primordial silicon” (15 November, p 30)
was, in fact, first noted over forty years ago.
Based on the observation that machine technology appeared to be developing an
evolutionary thrust of its own, a British hi-tech research initiative (the 1953
Minad Project) accurately predicted the emergence of a rapidly developing
planetary “nervous system” of computers and communications, the forerunner of a
global information superorganism.
Three evolutionary stages were envisaged: electronic wiring up of a global
thinking dimension (today’s Internet); transformation of the network into a
high-speed creative technology organism (Technosphere); finally, the emergence
of a fully developed global hyperintelligence (Autosphere).
Studies of “artificial” evolution have been carefully documented since 1953.
Minad’s predictive research is now concerned with the implications for planetary
life of 21st Century Technosphere and Autosphere runaway technologies.
Letters : Not by a gene alone
Port St Mary, Isle of Man
It’s nice to see the old group selection debate aired with a new twist in
your journal
(“The unselfish gene”, 25 October, p 28, and
Letters, 22 November, p 66).
What Dawkins and other “genetic imperialists” seem to neglect is that
selection can never be at the level of the single gene except under very special
circumstances; a clone of individuals in a homogeneous environment with some
individuals carrying a mutation in one gene. This seems unlikely apart from some
Moneran and Protoctistan populations.
For all other organisms it is the individual genome (organism or colony) that
is selected by evolutionary forces to survive or to be eliminated. When I finish
the evolutionary race behind the other runners do I blame my weak ankles, wobbly
knees or my propensity to overheat? Probably all of those, and more.
If we regard the niche as an n-dimensional hypervolume we must describe the
species as an n-dimensional hypersolid. The degree of fit between the niche and
the species must then be a measure of the selective force acting on any
individual within a species. In an organism with a large number of genes the
contribution of any one gene to that fit must be comparatively small, and other
genes may compensate for some of the effects of that gene. It is individuals who
don’t fit their niche very well that are eliminated, along with their whole
suite of genes.
It is easy to take a critical single gene such as the one responsible for
sickle cell disease and show how it appears to have selective advantage or
disadvantage. But can we really say it brought no other genes with it? In
general terms there are few traits the possession of one of which confers great
selective advantage on its own. I am reminded of the giraffe article that
appeared in New 杏吧原创 recently. The success of giraffes depends not
just on a long neck, but on the possession of a number of other adaptations to
compensate for the effects of the high blood pressure such an elevated intellect
requires.
After that I must lower my blood pressure with a tot of good Celtic cultural
practice, the supposed predilectary allele which I know has run in my family for
some generations (judging by their behaviour). But is that because of the
Scottish and Irish social contexts of my family’s evolution, or has this allele,
all on its own, conferred some beneficial adaptive ability?
No. No person can be reduced to a single psychological or behavioural
dimension, nor the fitness of any species be determined by a single gene.
Letters : . . . . .
Bristol
Using Gott’s longevity formula, I calculate that the low-frequency noise
known here as the Bristol Hum (caused by pressure differences within gas
transmission systems) will be around for between 18 months and 2340 years.
Unless we do something about it.
Letters : . . . . .
Wotton-under-Edge Gloucestershire
Is the logic Gott uses to predict the lifetime of something to an accuracy of
95 per cent any different from that used to predict with 100 per cent accuracy
that its lifetime will be between now and infinity?
I find it incredible that anyone can expound the “success” of a theory that
predicted the lifetime of the Conservative government to be between 4.3 months
and 546 years. And as an engineer, I also find it extremely irritating that
numbers like “4.3”, “546”, and “39” are quoted in connection with such an
inaccurate and useless theory.
Letters : . . . . .
Gott’s calculation suggests that a 39-year-old man has a 95 per cent
probability of living between 39/39 years (= one year) and 39 x 39 years (= 1521
years), but his baby child aged 0.39 years has a 95 per cent probability of
living one-hundredth as long, between 0.01 and 15.21 years. Of course we know a
great deal about the spread of human survival times so it’s clear this is
nonsense.
Gott implicitly assumes a very different distribution of potential survival
times, and its general applicability. The argument would get a bit more
interesting if that were explicit and its plausibility discussed with a serious
eye to the evidence. Meantime, I’d vote not to pay for the colonisation of Mars
on the basis of half a probability argument.
Letters : . . . . .
London
Unlike humanity, the Berlin Wall and the plays running on Broadway in 1993
never underwent any fundamental changes in their nature or behaviour. One cannot
compare entities that never change with one that does so continually.
Letters : . . . . .
Knighton, Powys
Theories, like other things in the Universe, appear to have shelf lives,
after which they are displaced by other theories. If we take the origin of
Gott’s theory as being 1993, the year when he expounded it in Nature,
then it should have a future life of between 2 months and 156 years.
Any new theory arising within this time frame which showed Gott’s theory to
be incorrect would simultaneously confirm and refute it.