Genetic Limits

Apparently there are maximum effective lifetimes for every species. For humans, that appears to be between 110 and 120 years. Hayflick (1977, 1994) theorized that there is genetically programmed upper age limit for species. In one experiment, human cells stopped dividing after 50 times, then entering a state of replicative senescence (Hornsby, 2001). Galapagos turtles's cells double 100 years; chickens 25 times. The limit for cell replication is called the Hayflick limit (Bjorklund & Bee, 2008).

Major Theorists

Leonard Hayflick (1977, 1994)

Hornsby (2001)

Citations to Major Works

• Hayflick, L. (1977). The cellular basis for biological aging. In C.E. Finch & L. Hayflick (Eds.), Handbook of the biology of aging (pp. 159-186). New York: Van Nostrand Reinhold.
• Hayflick, L. (1994). How and why we age. New York: Ballantine Books.
• Hornsby, P.J. (2001). Cell proliferation in mammalian aging. In E. J. Masoro & S. N. Austad (Eds.) Handbook of the biology of aging (pp. 207-245), San Diego: Academic Press.

Web Links

http://www.molecularstation.com/wiki/Hayflick_limit

http://www.antiagingempire.com/