Genetic Engineering / Cloning

Genetic engineering, altering the inherited characteristics of an
organism in a predetermined way, by introducing into it a piece of the
genetic material of another organism. Genetic engineering offers the
hope of cures for many inherited diseases, once the problem of low
efficiencies of effective transfer of genetic material is overcome.

Another development has been the refinement of the technique called
cloning, which produces large numbers of genetically identical
individuals by transplanting whole cell nuclei. With other techniques
scientists can isolate sections of DNA representing single genes,
determine their nucleotide sequences, and reproduce them in the
laboratory. This offers the possibility of creating entirely new
genes with commercially or medically desirable properties.

While the potential benefits of genetic engineering are considerable,
so may be the potential dangers. For example, the introduction of
cancer-causing genes into a common infectious organism, such as the
influenza virus, could be hazardous.

We have come to believe that all human beings are equal; but even more
firmly, we are taught to believe each one of us is unique. Is that
idea undercut by cloning? That is, if you can deliberately make any
number of copies of an individual, is each one special? How special
can clones feel, knowing they were replicated like smile buttons. "We
aren't just our genes, we're a whole collection of our experiences,"
says Albert Jonsen. But the idea, he adds, raises a host of issues,
"from the fantastic to the profound."

When anesthesia was discovered in the 19th century, there was a
speculation that it would rob humans of the transforming experience of
suffering. When three decades ago, James Watson and Francis Crick
unraveled the genetic code, popular discussion turned not to the new
hope for vanquishing disease but to the specter of genetically
engineered races of supermen and worker drones. Later, the arrival of
organ transplants set people brooding about a world of clanking
Frankensteins, welded together made from used parts.

Already there are thousands of frozen embryos sitting in liquid
nitrogen storage around the country. "Suppose somebody wanted to
advertise cloned embryos by showing pictures of already born children
like a product," says Prof. Ruth Macklin, of New York's Albert
Einstein College of medicine, who specializes in human reproduction.

Splitting an embryo mat seem a great technological leap, but in a
world where embryos are already created in test tubes, it's a baby
step. The current challenge in reproductive medicine is not to
produce more embryos but to identify healthy ones and get them to grow
in the womb. Using genetic tests, doctors can now screen embryonic
cells for hereditary diseases. In the not to distant future, prenatal
tests may also help predict such common problems as obesity,
depression and heart disease. But don't expect scientists to start
building new traits into babies anytime soon. The technological
obstacles are formidable, and so are the cultural ones.

Copies of humans are identical, but are the people the same? Probably
not. For a century scientists have been trying to figure out which
factors play the most important role in the development of a human
personality. Is it nature or nurture, heredity or environment? The
best information so far has come from the study of identical twins
reared apart. Twins Jim Springer and Jim Lewis, separated at birth in
1939, were reunited 39 years later in a study of twins at the
University of Minnesota. Both had married and divorced women named
Linda, married second wives named Betty and named their oldest sons
James Allan and James Alan. Both drove the same model of blue
Chevrolet, enjoyed woodworking, vacationed on the same Florida beach,
and both had dogs named Toy.