Dr. Jay Wile has an excellent summary of C.S. Lewis’s beliefs about evolution on his Proslogion blog: Another Point About C.S. Lewis.
To summarize the summary:
- Lewis refused to join or endorse the Evolution Protest Movement, even though it was led by a personal friend.
- His writings state acceptance of biological evolution [and, I should add, an ancient Earth (and Mars!)].
- Lewis believed that evolution posed little threat to Christianity.
- Lewis didn’t even believe in a literal Adam and Eve
- Despite these beliefs, most would consider Lewis very orthodox in his Christian beliefs.
Grace and Peace
GeoChristian 
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