Age of the Earth

I would add:

Carbon dating has been used since the late 1940s to establish how long ago a member of a certain species lived and died.

and

There are trees living today that are far older than 4000 years.

I had a funny chat with a park ranger in the Sierra Nevada where I had taken my son and some friends camping.  The office where we were to get our permits had a display of some of these older trees and explained how scientists have confirmed their ages.  I ask the woman, “I’m sure you have an occasional visitor who disputes this on the basis of biblical texts.  How do you deal with that?”  She responded, “By changing the subject–immediately. Trust me; I’ve gotten quite adept at this over the years. Did you know that black bears are the least dangerous of their genus?”