Part narrative history, part philosophy of science Tudge's book takes for its subject the science of genetics. Seemingly this subject has, in one form or another, been highly relevant for a century and a half, though as the author points out that relevance has not always been understood.
The titular Mendel was much more than the gardening monk that some histories have portrayed him as, he was, as Tudge contends, a true scientist. A contemporary of Darwin, Mendel made an observation regarding the nature of our heredity that would eventually provide the mechanism by which natural selection works.
Neither Mendel nor Darwin would live to see the unification of their works in the New synthesis or Neo-Darwinism, in all probability Darwin may have been only vaguely aware of Mendel's studies. Few then understood then quite what this work meant.
Everything that has come since, Tudge tells us, is merely a footnote to that original work. If so it has to be one the most interesting of footnotes and he explains it all with great clarity. He takes us from the discovery of the DNA, how it works and the ways in which humans are beginning to manipulate it. The gene's central role in our evolutionary story and the previously maligned field of evolutionary psychology are also opened up to the reader. Like all good popular science writing the author satisfies the curiosity whilst at the same time whetting it further.
It is in the last chapter that Tudge moves from 'is' to 'ought', or at least tries to frame how the discussion of 'ought' might be carried out. He warns against hubris and selfish motivations in deploying such powerful technologies. At the last, Mendel has more to teach us, as much by example as by intellect.