Human origins and evolution: Cold Spring Harbor, deja vu.

The Cold Spring Harbor Symposia of the 1950s were key to integrating human evolutionary studies into biology. That integration provided a solid foundation for systematic and functional interpretations of an expanding base of fossil and molecular evidence during the latter half of the 20th century. Today, the paleontological record of human evolution amassed during the last 150 years illuminates the human clade on life's tree. However, the rise of Hennegian parsimony cladistics and punctuationalism during the end of the last century witnessed the partial abandonment of classificatory conventions cemented by Mayr, Simpson, Dobzhansky, and others at Cold Spring Harbor. This has led to an artificial, postmillennial amplification of apparent species diversity in the hominid clade. Work on a stratigraphically thick and temporally deep sedimentary sequence in the Middle Awash study area of Ethiopia's Afar Depression reveals an assembly order of hominid anatomies and behaviors that was impossible for Darwin to discern. Large parts of that record appear to reflect phyletic evolution, consistent with the lessons and expectations of Cold Spring Harbor in 1950. Molecular biology cannot reveal the assembly sequences or contexts of human origins and evolution without reference to adequate geological, geochronological, paleobiological, and archaeological records. Today's consilience of these disparate data sets would have impressed Charles Darwin.