This document summarizes some key similarities and differences between pre-Columbian North America and Europe, including their animals, diseases, technology, and population characteristics. It argues that the availability of easily domesticated large animals in Europe allowed the development of large-scale agriculture, population growth, and specialization that drove innovations, whereas North America lacked such animals. The document suggests the different trajectories of the two cultures can be largely explained by differences in their lands and the species available for domestication.