Human Evolution: A bush or a ladder?

Professor Bernard Wood is University Professor of Human Origins at the George Washington University.
He is a medically trained paleoanthropologist whose research interests are related to a long-standing pre-occupation with hominin systematics.
How can we improve our ability to recognize species in the fossil record, and how can we do a better job of reconstructing their phylogenetic relationships?
His other research interests include dental evolution, evolvability within the hominin clade, and diet reconstruction.