In meiosis, the specific process occurring during certain phases (particularly during prophase I) is called crossing over or genetic recombination.
This process is beneficial to organisms because it increases genetic diversity in the gametes. By exchanging genetic material between homologous chromosomes, crossing over creates new combinations of genes, which can lead to variation in traits among offspring. This variation is crucial for evolution and adaptation, as it enhances the chances of survival in changing environments. Additionally, genetic diversity can improve the resilience of populations against diseases and environmental changes.