Evolutionism says just the opposite. Is not the whole notion of development a process from the imperfect to the perfect? But the eternal question abides -- What begot the first germ, containing in itself the promise and potency of the vast development which we see? St Thomas asserts a priority of nature of the perfect to the imperfect, not a priority of time. God, though prior in duration, is not prior in time to the creature, as He is not in time at all: there is no time antecedent to creation. In the series of created causes, the imperfect is doubtless prior in time to the perfect. The first verses of Genesis assure us of that, as well as all sound study of evolution.
Of God and His Creatures: 1.44