The word `Eugenics` frightens a lot of people, because it clearly has dark applications. However, it is a topic that must be covered in any discussion of life, especially human life and its future direction.

The following link appears to be quite a detailed discussion, although the book has not been read, so some resrervation about its conclusion must also be made at this stage:

http://whatwemaybe.org/txt/txt0000/glad.john.2006.future_human_evolution.book.002k2.en.pdf