Re: Is there enough genetic material in human feces or a human hair to clone?

This is a great question, because you have identified an issue where biology and technology have different answers. Every somatic cell (those that aren't sperm or eggs) in the human body contains the same genetic information. (Sperm and eggs have half the information content of somatic cells.) Thus, every cell in your body theoretically contains the information necessary to make an organism. The cloning of farm animals such as the sheep Doll y was accomplished by using somatic cells.

Both hair and feces have some cells in them, so in theory they could be used for human cloning. However, it is technically challenging to prepare cells for somatic cloning. It would be very difficult to take a hair cell or a cell embedded in feces and use it to generate a new human. Scientific American has an article that gives an excellent overview of the issues involved in human cloning.

There are a number of technological barriers to cloning, even if the starting cells are more abundant than those in hair or feces. A detailed discussion of the challenges of cloning is available. Briefly, the process of generating clones is complicated. It requires removing the nucleus (which contains the DNA) from an egg cell and replacing it with the nucleus of a somatic cell. This nuclear transfer doesn't work perfectly: one needs many eggs and many egg recipients. Many of these eggs with transferred nuclei fail to develop. Also, the age of the somatic cell used to clone is important--it appears that the health of the cloned animal may be affected by how old the cell was that it started with.

Although it is unlikely that someone will clone you from an errant hair, it is currently easy to do simple DNA identification from crime-scene evidence such as hair or blood. This is because DNA is pretty stable, and while a cell may not survive well when detached from the body, the cell's DNA will persist well enough for study.