Benedict XVI addresses the members of the Pontifical Academy of Sciences on the occasion of their plenary assembly being held in Rome.VATICAN CITY, NOV. 6, 2006 (Zenit.org)
As some of the papers presented in the last few days have emphasized, the scientific method itself, in its gathering of data and in the processing and use of those data in projections, has inherent limitations that necessarily restrict scientific predictability to specific contexts and approaches. Science cannot, therefore, presume to provide a complete, deterministic representation of our future and of the development of every phenomenon that it studies. Philosophy and theology might make an important contribution to this fundamentally epistemological question by, for example, helping the empirical sciences to recognize a difference between the mathematical inability to predict certain events and the validity of the principle of causality, or between scientific indeterminism or contingency (randomness) and causality on the philosophical level, or, more radically, between evolution as the origin of a succession in space and time, and creation as the ultimate origin of participated being in essential Being.At the same time, there is a higher level that necessarily transcends all scientific predictions, namely, the human world of freedom and history.
Whereas the physical cosmos can have its own spatial-temporal development, only humanity, strictly speaking, has a history, the history of its freedom. Freedom, like reason, is a precious part of God's image within us, and it can never be reduced to a deterministic analysis. Its transcendence vis-à-vis the material world must be acknowledged and respected, since it is a sign of our human dignity. Denying that transcendence in the name of a supposed absolute ability of the scientific method to predict and condition the human world would involve the loss of what is human in man, and, by failing to recognize his uniqueness and transcendence, could dangerously open the door to his exploitation.
*humans have free will and so their behavior cannot be--and will not ever be--perfectly predictible merely from observations of the natural order.
*That we cannot predict certain *natural* phenomena does not mean that they are not caused.
*That we evolved along a certain course does not explain why we did so. *That* we did and *why* we did are two separate questions. The natural sciences are capable of addressing the first but not the latter question.
For more on this see Stephen Barr's excellent pair of essays in First Things: The Design of Evolution
and The Miracle of Evolution