It's too long to summarize concisely. But the gist is that computing and biotechnology are the leading technologies of the past decade, and almost certainly of the next several decades. While they are not exactly merging (yet -- that's another decade or two away), they are starting to overlap significantly at the cutting edge.
Venter leads off with a discussion of how rapid progress in genomics will affect developments in cancer, antibiotics and antivirals, and synthetic biology (synthesizing living organisms). Kurzweil speculates about how radical advances in treatments for infectious and systemic diseases may occur sooner than most expect. Brooks explains why he thinks we need to understand much more about biology before we can make further progress in such fields as robotics and artificial life.
After the introductory remarks, Kurzweil and Brooks debate how rapidly dramatic progress in the science and technology of biocomputation should be expected to occur. The disagreements revolve around questions about how long it will take to really understand extremely complex systems such as individual cells and the human brain.
The discussion as a whole is a good introduction to the science of the 21st century.
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