Martin A. Nowak is Professor of Mathematics and of Biology at Harvard University. He works on the mathematical description of evolutionary processes, including the evolution of cooperation and human language, as well as the dynamics of virus infections and human cancer. His major scientific contributions and discoveries include: a proposed mechanism of HIV disease progression; the rapid turnover and evolution of drug resistance in HIV infection; quantifying the dynamics of HBV infection; evolution of virulence under superinfection and coinfection; the role of chromosomal instability in human cancer; quantifying the dynamics of chronic myeloid leukemia; the accumulation of drivers and passengers in cancer progression; the evolution of drug resistance in targeted cancer therapy; the mechanisms for the evolution of genetic redundancy; "generous tit-for-tat" and "win-stay, lose-shift"; the alternating Prisoner's Dilemma; the evolution of cooperation by indirect reciprocity; spatial game dynamics; adaptive dynamics; evolutionary game dynamics in finite populations; evolutionary graph theory; five mechanisms for the evolution of cooperation; evolution of eusociality by natural selection; a mathematical approach for studying the evolution of human language; culturomics; "winners don't punish"; prelife; and the origin of evolution.