What must happen in order for a species to evolve?

For a species to evolve, genetic variations must occur within its population, often due to mutations, gene flow, or sexual reproduction. These variations provide a basis for natural selection, where certain traits become more advantageous for survival and reproduction in a given environment. Over time, the accumulation of these advantageous traits can lead to significant changes in the species, ultimately resulting in evolution. Environmental pressures and changes also play a crucial role in shaping which traits are favored.