TY - RPRT TI - How often do Protein Genes Navigate Valleys of Low Fitness? AU - Nelson, E. D. AU - Grishin, N. V. PY - 2019 DO - 10.1101/592444 UR - https://www.biorxiv.org/content/10.1101/592444v1 ID - 10.1101/592444 ER -