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The Raelian Movement
for those who are not afraid of the future : http://www.rael.org
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Reconstructing human appearance from DNA
http://www.cosmosmagazine.com/news/3748/reconstructing-human-appearance-dna
Tuesday, 21 September 2010
by Andrew Letten
Cosmos Online
Forensic biologists think that one day they may be able to construct
the physical characteristics of a criminal from DNA left behind at the
scene.
SYDNEY: Police sketch artists might soon be trading in the pencil and
paper for a genetics lab. Forensic biologists say they may soon be
able to reconstruct a criminal's profile from the DNA they leave at a
crime scene.
This would potentially render DNA databases obsolete, said molecular
biologist Manfred Kayser from Erasmus MC in Rotterdam in his keynote
address at the 20th International Symposium of Forensic Science, in
Sydney in September.
This kind of approach could revolutionise police work. Particularly in
relation to so called 'cold-cases', where the DNA sample does not
match a suspect's profile or that of any criminal in a DNA database,
Kayser said.
Gender and pigmentation
"We don't yet know if it's possible to find accurate genetic markers
for individual specific traits [such as facial dimensions] ... if we
do, it could eventually mean that criminal databases won't be needed.
For now that's of course science fiction," Kayser told the Sydney
audience.
Most physical characteristics are complex traits, defined by several
interacting genes and possibly environmental factors too. Yet, Kayser
and others in the have already identified several DNA markers that
determine various physical characteristics, including gender, hair
colour, eye colour have already been discovered.
The simplest characteristic to determine with a DNA sample of unknown
human origin is gender. The gene for amelogenin (a protein involved in
tooth development) can be used in sex determination of samples,
because the length of the gene is different on the X chromosome to the
Y chromosome. This is a relatively robust, but not foolproof, gender
test, according to Kayser.
Hair colour prediction underway
Beyond gender, the human traits with highest predictive accuracy are
those affected by pigmentation, simply because they are the least
complex. Red hair colour, which is determined by a single gene, can be
predicted with a certainty of around 93%.
For other hair types, accuracy is slightly lower, but still promising.
Kayser reported confidence levels as high as 85, 81 and 80% for
predicting black, brown and blond hair respectively.
Perhaps the most progress has been made in determining eye colour:
Kayser and colleagues reported that using DNA they could predict with
90% confidence if a person of European origin had blue or brown eyes,
based on an analysis of just six positions on the genome.
Eye colour, height and even age next
Although the predictive accuracy is less robust for intermediate eye
colours, new genes, involved in the subtle variation of iris colour,
are being discovered all the time, Kayser said.
Some traits, however, are inherently problematic. While height is a
classic example of an inherited trait, it is notoriously difficult to
predict. This is because there are more than 50 DNA markers associated
with height.
Kayser also alluded to alluded to research, in press, detailing tools
for predicting human age. Thus far, the most promising technique for
separating the young from the old involves the analysis of ribonucleic
acid (RNA) - a molecule chemically similar to DNA but principally
involved in protein synthesis and gene expression.
There is also emerging data for a raft of other traits, such as skin
colour, freckles, baldness and hair morphology, Kayser said.
"Ethics" is simply a last-gasp attempt by deist conservatives and
orthodox dogmatics to keep humanity in ignorance and obscurantism,
through the well tried fermentation of fear, the fear of science and
new technologies.
There is nothing glorious about what our ancestors call history,
it is simply a succession of mistakes, intolerances and violations.
On the contrary, let us embrace Science and the new technologies
unfettered, for it is these which will liberate mankind from the
myth of god, and free us from our age old fears, from disease,
death and the sweat of labour.
Rael
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