Genetics in Context offers a dual timeline, with scientific events (especially those relevant to classical genetics) presented against those of general historical and cultural interest. Did you know that Darwin published Origin of Species the year before Lincoln was elected President, while Mendel published his findings the year after Lincoln was assassinated?
The comparative timeline is available at http://www.esp.org/timeline as part of the Electronic Scholarly Publishing project.
The ESP site ( http://www.esp.org/ ) is dedicated to the electronic publishing of scientific and other scholarly materials. Of particular interest are the history of science, genetics, computational biology, and genome research.