Life on earth is extremely diverse. So much so that we are still discovering new life in even the most hostile environments. Deep in the ocean, in pools of boiling sulfur water; places where once we would have never expected life to occur.
Many put this down to the quasi-infinite variability caused by natural selection. Life has a way of modifying itself to multiple environments. According to Spiritism, this is partially true … only that many transformations were given a push or directed by the spirit realm is missing from Darwin’s theory.