Problem: The Bible teaches that humans only live for 120 years. However, recent people have stepped forward, claiming to be over 120 years old. In fact, the text claims that Noah himself lived another 350 years after the Flood, as did many of his descendants (see Gen. 11). What should we make of this claim?
Solution: There are two options for understanding this claim:
Option #1: This length of time refers to the time before God flooded the Earth in Noah’s time. Most interpreters hold to this view.
Option #2: This length of time refers to the length of human life after Noah’s time. Interpreters who hold to this view claim that the effects of the life-shortening are not dogmatic or even immediate. Notice, for example, how the length of men’s ages slowly decreases in Genesis 11. They would claim that this decree of God took time to go into effect.
Scientific research supports this second option. Our cells cannot live far beyond 120 years long, because of a phenomenon called apoptosis. Ross writes, “Apparently, our cells are designed to shut down after a certain number of cell regenerations. Apoptosis means that no matter how healthy and safe a lifestyle and person leads, he or she will not live beyond about 120 years.” Even skeptic Michael Shermer affirms this, when he writes,
For humans, the record for the oldest documented age ever achieved is 120 years. It is held by Shigechiyo Izumi, a Japanese stevedore. There are many undocumented claims of people living beyond 150 years and even up to 200 years; these frequently involve such cultural oddities as adding the ages of father and son together. Data on documented centenarians (people who live to be 100 years old) reveal that only one person will live to be 115 years old for every 2.1 billion people.
Ross thinks that human life was shortened by the Vela supernova, which bombarded the Earth with radiation at this time.
 Ross, Hugh. The Genesis Question: Scientific Advances and the Accuracy of Genesis. Colorado Springs, CO: NavPress, 1998. 121.
 Shermer, Michael. Why People Believe Weird Things: Pseudoscience, Superstition, and Other Confusions of Our Time. New York: W.H. Freeman, 1997. 83-84.
 Ross, Hugh. The Genesis Question: Scientific Advances and the Accuracy of Genesis. Colorado Springs, CO: NavPress, 1998. 119-125.
“And the Lord said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years.