Question of the week: How long have humans been on Earth? How do you square that date with the biblical genealogies that imply roughly 4,000 years from Adam to Jesus of Nazareth?
My answer: I answer this question in detail in Navigating Genesis.1 None of the genealogies in the Bible, including those in Genesis 5 and 11:10–26, are exhaustively complete. Each one has missing names. The names that are included are intended to make specific theological points. The theological points can be discerned by noting which names are omitted and which are included. In the Matthew 1:1–17 genealogy, for example, the names of kings who led wicked reigns and did not repent are omitted. Matthew 1 also names the wives of four of the named men, some of whom were not Jews by blood and some who had committed serious sins. Matthew here implies that the gospel offer of salvation is not just for male blood descendants of Jacob but for all who repent of their sin and turn to their Messiah. For three web articles by our guest scholars on the Genesis 5 and 11 genealogies, go here and here and here.
The best biblical date for Adam and Eve comes from Genesis 2. Genesis 2 states that four known rivers come together in the Garden of Eden. The only location where they do come together is in the southeastern part of the Persian Gulf. Presently, it is more than 200 feet below sea level. However, during much of the last ice age, this location was above sea level. This sea-level constraint implies that God created Adam and Eve between 15,000 and 130,000 years ago.
The best scientific dates for the origin of the human race range from 300,000 years ago to 45,000 years ago. For an article on the statistical and systematic errors impacting scientific attempts to date the origin of humanity, go here.