When I get into arguments on evolution--unfortunately a frequent occurrence in my hometown--I reflexively point to microbes and their impressive ability to evolve new properties literally right before one's eyes (viz. antimicrobial resistance) as incontrovertible evidence of the veracity of evolution by means of natural selection.
I have often wondered how much further mankind's knowledge would be if the genius Darwin had the microbial world to draw from when identifying the earth-shattering facts he did.
An esteemed group of microbiologists has picked up Darwin's mantle and written a collection of essays that melds Darwinian principles with cutting edge microbiology. The collection is appropriatley entitled Microbes and Evolution: The World Darwin Never Saw. The essays in this book, by making bold new integrations, furthers the philosophy of biology and provides a plethora of ideas to spend hours chewing.
The essays have varied topics but each illustrates the simple elegance of evolutionary machinery at work on the 3 kingdoms of life (Archae, prokaryotes, and eukaryotes) alike. For an infectious disease physican who hasn't delved enough into "pure" (non-medical) microbiology, the book was a treasure trove.
I highly recommend it.