THE TREE OF LIFE: STEPHEN JAY GOULD’S CONTRIBUTIONS TO SYSTEMATICS
Goulds views on cladistics, that great 20th century innovation of systematic method, were often misunderstood. He did take issue with the marginalization of unique traits and similarities in the biological role of taxa, and he saw major pitfalls in basing taxonomic classifications on cladograms. However, Gould valued cladistics as the best method for reconstructing branching order, and therefore for working out the historical patterns of the origin of traits. In his writings, he cited cladistic studies that challenged notions of gradual, predictable, progressive evolutionary change. Most importantly, Gould saw the cladistic emphasis on branching as essential to recognizing species as discrete evolutionary individuals with a reality in nature, a notion that is central to his hierarchical view of macroevolution.
Gould had great respect for traditional systematic work, speaking and writing with reverence about the authors of major taxonomic monographs from Linnaeus to modern scientists. He always argued that systematics was a theory-driven and vibrant field; the best systematic works, including his own, are both creative and transformative, altering or even revolutionizing our views on evolution.