Coevolution of living things and their surroundings contributes to the biodiversity on Earth. Combining with the abiotic-biotic regulatory concept, the Gaia theory, and the philosophical view in ancient China, we believe the physical river evolution must somehow takes on biological evolution characteristics, and the river biosphere could be an anti-entropic system and develop towards the higher beings. Here, beyond the traditional understanding of river, we redefine a kind of systematic out-branching (Dragon style) river which is characterized by a systematic connection between the stable, unobstructed main-channel and the active, open, abducent out-branches under some high-resistant environmental conditions (especially in tropical and polar zones). It has the potential to help detect the signatures of life on other planets which are similar in river landscape to Earth.