Our Lord Jesus Christ said to St. Peter, "...whatsoever you bind on Earth shall be bound in Heaven, and whatsoever you loose on Earth shall be loosed in Heaven."
With that understanding, we must accept the record of Scripture AND the interpretation of same by Holy Church as infallible. There are things which the sciences continue to discover, and some of them are harmonious with Scripture, and some are at odds with Scripture. We must obey the Voice of God on Earth, which is the Church.
We must also remember that there were 'major scientific discoveries' centuries ago that are now considered ludicrous because new information has been gained. I am not suggesting that we disregard science, but rather that we remember that science has at its core the desire and the goal of change, forward motion and progress, which necessarily means that scientists will one day repudiate what they previously believed.
The Church, on the other hand, moves forward IN time but not WITH the times; Her dogmas are infallible and there is no new revelation that can or will ever supersede what She already teaches us.
Thus, we are always to rest on the Authority which has been placed over us, namely, Our Lord Jesus Christ and His Holy Church.
I, personally, don't see any need to believe that man was or was not created X number of years ago. What the Bible says is that God Almighty created the world in six days. Whatever time period the word 'day' represents is immaterial to me. There are no definitions of the creation account that are de fide, so I don't concern myself with them.
Immaculate Heart of Mary, triumph soon.
Sacred Heart of Jesus, have mercy on us.