Digital evolutions are significant and autonomous. They changed mono-cellular Prokaryote to multi-cellular Eukaryote, and unreliable personal computer communication to self-regulative computer networks with Forward Error Correction. (Tanenbaum Weatherall 2011) Based on simple and distributed logic, a digital system autonomously evolves itself. The complexity and sophistication of modern human language should be digital evolution of mammal analog vocal sign communications. There is no modern human unique brain structure for linguistic processing, such as Language Acquisition Device or Language Brain. It is the mammal or vertebrate sign reflex mechanism that acquires language through learning and thought operations. As Table-1 indicates, infinite word generation and grammatical modulation were obtained at the first stage of digital linguistic evolution.