Genesis expresses theological truths – our relationship to God.
God’s perfect creation is symbolized by the Garden of Eden. Perfection is followed by the fall. The fall is the coming into the world of sin and disorder. Genesis puts all the blame on a woman – I don’t want to argue about that just now.
In essence, Genesis shows that God created life and it was good. But over time it fell. It became imperfect.
Evolution fits into the picture as part of the fall. It is imperfect, based on mutation and it occurs over time.
There are two parallels here: the fall was a rebellion against God and a mistake, but it led to our redemption – so the fall was not all bad news.
Likewise, evolution is based on mutational error and so a mistake, but it leads to diversity and adaptation in the natural world, so evolution is not all bad news.
Evolution produces what is beautiful as well as what is ugly. The beautiful is the many different species of plants and animals we see around us; the ugly includes parasites that not only look ugly but also do horrible things to other creatures. So evolution is part of a fallen imperfect world.
It is not all bad news:
In the Easter Vigil liturgy the priest sings about the fall of Adam and Eve, ‘Oh happy fault, the fault that brought our redemption’. He sings this because the fall brought about our redemption through Jesus Christ. But just as the priest sings ‘Oh happy fault’ at the Easter Vigil referring to the fall, we can sing ‘Oh happy error’ referring to mutation since the processes of evolution have led to a great diversity of species adapted to the different environments on earth.
It is the original perfection and complexity of the genetic system that has allowed the evolution of diverse forms of life through genetic switching off.
Genetic switching off produces ‘lucky dysfunctions’ in that it guides a complex system towards new ends. You could call this a ‘tuning up’ of the original system.
The Principles of Creation 