Friday, March 03, 2006

the transhuman condition


I Will Fear No Evil is a science fiction novel by Robert A. Heinlein published in 1970. Ancient billionaire Johann Sebastian Bach Smith is dying, and wants to have his brain transplanted into a new body.

Smith advertises an offer of a million dollars for the donation of a body from a brain-dead patient. Coincidentally, his beautiful young female secretary, Eunice Branca, is murdered, so her body is used, since Smith never thought to place any restriction on the sex of the donor. He is rechristened Joan.

The book itself is not Heinlein's best work but it does contain some of his best predictions, inlcuding the stenodesk, identical to an integrated desk/pc.(Heinlein's 1957 novel The Door Into Summer similarly envisaged the development of CAD systems, and his 1982 novel Friday portrayed something very like the modern Internet.) The novel is also notable as one of SF's first sympathetic fictional portrayals of a same-sex couple.

More notable is the real physical questions of whole-body transplants, which are brushed aside for a more psychological look at a man in a woman's body, almost a comedic cliche by now and making Heinlein appear as sort of a lech.Heinlein suffered from life-threatening peritonitis while working on this novel, and it is generally believed that his wife Virginia handled much of the editing.

A whole-body transplant, or brain transplant, moves the brain of one being into the body of another. It is a procedure distinct from head transplant, which involves transferring the entire head to a new body, as opposed to the brain only. No technology currently exists to perform brain transplants.

Although many scientists would challenge the feasibility of this process, few would say that it is not eventually possible given current research into organ transplant and human cloning. Some bioethicists would argue that there are difficult moral problems involved in either harvesting a brain-dead body, especially one deliberately created using human cloning, or otherwise acquiring a body (say, of a criminal due to be executed for a crime, or an individual who is not dead but is soon to die of a brain-based illness).

Whole-body transplant is similar in some ways to the idea of downloading consciousness promoted by Marvin Minsky and others with a mechanistic view of natural intelligence and an optimistic outlook regarding artificial intelligence. It is also a goal of Raelism, a small cult based in Florida, France, and Quebec. However, while the 'downloaders' see the ultimate receptacle of the human brain as a repairable manufactured body made by robotics, the 'transplanters' see the ultimate receptable as a new body optimized for that brain by genetics and maybe proteomics.

It has been pointed out that the age of a body that a brain could be transplanted into should be sufficient - the adult sized brain could only fit into the skull of a body post 9-12 years old as that is when the head reaches adult size.

The procedure seems to be a far-off goal. However, it should be noted that human cloning itself seemed impossible a generation ago.

With completion of a rough draft of the human genome, many researchers are now looking at how genes and proteins interact to form other proteins. A surprising finding of the Human Genome Project is that there are far fewer protein-coding genes in the human genome than there are proteins in the human proteome (~22,000 genes vs. ~400,000 proteins). The large increase in protein diversity is thought to be due to alternative splicing and post-translational modification of proteins.

To catalog all human proteins and ascertain their functions and interactions presents a daunting challenge for scientists. An international collaboration to achieve these goals is being co-ordinated by the Human Proteome Organisation.

One of the most significant barriers to the procedure is the inability of nerve tissue to heal properly; scarred nerve tissue doesn't transmit signals well (this is the reason a spinal cord injury is so devastating). However, recent research at the Wistar Institute of the University of Pennsylvania involving tissue-regenerating mice may provide pointers for further research as to how to regenerate nerves without scarring.

Regeneration is the ability to restore lost or damaged tissues, organs or limbs. It is a common feature in invertebrates, but far more limited in most vertebrates. Nevertheless, even humans possess some degree of regeneration ability. Children under 6 years of age are capable of regenerating lost fingertips and the human liver retains its ability to regenerate throughout a person's lifetime. Aside from being used to generally describe any number of specific healing processes, regeneration also is a specific method of healing that is noted for its ability to regrow lost limbs, severed nerve connections, and other wounds. This is present in some animals such as the newt, hydra, and a type of mouse. [1] [2]. With the exception of the MRL mice, mammals do not in general have the ability to regenerate. If the processes behind regeneration are fully understood, it is believed this would lead to better treatment for individuals with nerve injuries, broken backs, paralysis, and missing limbs.

Regeneration of a lost limb occurs in two major steps, first de-differentiation of adult cells into a stem cell state similar to embryonic cells and second, development of these cells into new tissue more or less the same way it developed the first time. Some animals like planarians instead keep clusters of non-differentiated cells within their bodies, which migrate to the parts of the body that need healing.

MRL mice is a strain of mice that have been found to have a regenerative ability that in some cases rival urodele regeneration. Since this mice strain demonstrate that mammals possibly can regenerate, it is thought that humans also might have an innate regenerative ability that might be able to activate.By comparing the differential gene expression of scarless healing MRL mice and poor healing C57BL/6 mice strain, 36 genes have been identified that are good candidates for studying how the healing process differs in MRL mice and other mice.

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