In reply to your 1/22 post Why can't they both be literal? (fivedoves.com)I didn't realize that a thousand generations in the Bible is not considered literal, but in thinking about it a thousand generations would be at least 40 years to a generation x 1,000 generations would be 40,000 years.  If the Earth has only been around for 6,000 years, then the 40,000 years would reach past the Lord Jesus' Christ's 1,000 year reign on Earth when the 7,000th year ends.  If at the end of his 1,000 year reign, people are either given an immortal body and receive everlasting life or they are thrown into the lake of fire, there won't be any more generations of human beings to populate the Earth.

However, in the beginning the first 11 generations from Adam to Shem there are more than 40 years between generations.