Answer:
the three statements are true
Step-by-step explanation:
Gradualism refers to a scientific theory that states that the emergence of new life forms, especially at the species level, is due to gradual steps, instead of abrupt steps (conversely to the idea of catastrophism). Darwin's theory states that evolution is a gradual process, suggesting that extreme phenotypic changes are removed by natural selection. Thus, gradualism indicates that selection and variation are processes that occurr slowly, while conspicuous phenotypic changes observed among higher taxa are due to the accumulation of many small morphological variations over evolutionary time.