The Bibliomania Study Guide for The Time Machine provides some more perspective on Wells' work, and there are a range of biographies such as The Early H.G. Wells by Bernard Bergonzi (1961), or H.G. Wells: Discoverer of the Future by Lovat Dickson (1972). For a brief and critical view of Wells as seen from the 1940s, George Orwell's essay, Wells, Hitler and the World State can be found in Orwell's Penguin Essays.
For a full discussion of the evolution of sex and the role played by disease, see Matt Ridley's The Red Queen.