Scientists replicate key evolutionary step in life on earth 0 Randall Gross ScienceJanuary 2012Monday, January 16, 2012 at 2:15 pm PST • Views: 1,293 physorg.com Big Surprise Centrifuge Evolutionary Biologists Famous Multi-cellularity Gap Key Evolutionary Step Multi-cellular Clusters Multi-cellular Complexity National Science PNAS Paper National Academy Yeast Cells Single-celled Organism