Hayflick limits [Leonard Hayflick, American microbiologist, b. 1928; L, limes, border] , the concept that the life span of living organisms is limited by the number of times that somatic cells will subdivide. On the basis of human cells in cultures, where divisions occur about 50 times, it is estimated that the average human life span is limited to around 115 years. See also deliberate biological programming.
