processes that involve organisms from different generations take place over a period of at least 1 to many generations
grandfather is direct_relative_two_generations_past. metagenesis is not alternation_of_generations. biogenesis is not generation. thelygeny is monogeny. generation is not reproduction. generation is time_period. degeneration is process. metagenesis is alternation_of_generations. generation is reproduction. biogenesis is generation.