The Bible contains many accounts of long-lived humans, the oldest being Methuselah living to be 969 years old (Genesis 5:27). Today some maintain that the unusually high longevity of Biblical patriarchs are the result of an error in translation: lunar cycles were mistaken for the solar ones, and that the actual ages being described would have been 12.4 times less (a lunar cycle being 29.5 days). This makes Methuselah's age only 78. This rationalization, however, seems doubtful too since patriarchs such as Mahalalel (ibid 5:15) and Enoch (ibid 5:21) were said to have become fathers after 65 "years". If the lunar cycle claim were accepted this would translate to an age of about 5 years and 3 months. One Christian apologist claim is that the life span of humans has changed; that originally man was to have everlasting life, but due to man's sin, God progressively shortened man's life in the "four falls of mankind" -- first to less than 1000 years, then to under 500, 200, and eventually 120 years. After those long living people died, God decided that humans would not be permitted to live more than 120 years (Genesis 6:3.) However, since later biblical figures (and actual people) such as Sarah lived for longer than that, 120 years should be considered the "usual" upper limit to man's lifespan. Some individuals can live slightly longer than that. Furthermore, starting with reformers John Calvin and Martin Luther, an alternative explanation has arisen : 120 years would not refer to man's lifespan but to the amount of time left before the flood.
A more commonly accepted explanation is that such stories are longevity myths; age exaggeration tends to be greater in "mythical" periods in many cultures; the early emperors of Japan or China often ruled for more than a century, according to tradition. With the advent of modern accountable record-keeping, age claims fell to realistic levels; even later in the Bible King David died at 70 years; other kings in their 30s, 40s, and 50s.