Phylogenetic Systematics, first published in 1966, marks a turning point in the history of systematic biology. Willi Hennig's influential synthetic work, arguing for the primacy of the phylogenetic system as the general reference system in biology, generated significant controversy and opened possibilities for evolutionary biology that are still being explored.
 
 

The late Willi Hennig was director of phylongenetic research at the State Museum of Natural Science, Stuttgart. His honors included the Gold Medal of the Linnaean Society and the Gold Medal for Distinguished Achievement in Science of the American Museum of Natural History