Genes,”NewYorkTimes,Aug.31,2006;K.Christensen
and A.M.Herskind,“GeneticFactors Associatedwith
IndividualLifeDuration:Heritability,”inJ.M.Robineet
al.,eds.,HumanLongevity,IndividualLifeDuration,and
the Growth of the Oldest-Old Population (Springer,
2007).
33 If our genes explain less: Gavrilov and
Gavrilova, “Evolutionary Theories of Aging and
Longevity.”
34 Hairgrowsgray:A.K.FreemanandM.Gordon,
“Dermatologic Diseases and Problems,” in Geriatric
Medicine,ed. Cassel, 869.
34 Insideskin cells:A.Termanand U.T.Brunk,
“Lipofuscin,”InternationalJournalofBiochemistryand
CellBiology 36 (2004):1400–4; FreemanandGordon,
“Dermatologic Diseases and Problems.”
34 The eyes go: R. A. Weale, “Age and the
TransmittanceoftheHumanCrystallineLens,”Journal
of Physiology395 (1988): 577–87.
35 the“rectangularization”ofsurvival:Olshansky,
“The Demography of Aging.” See also US Census
Bureaudata for1950, http://www.census.gov/ipc/www/
idbpyr.html. Additional data from Population Pyramid
online,http://populationpyramid.net/.
36 We cling to the notion of retirement: M. E.
Pollack, “Intelligent Technology for an Aging
Population: The Use of AI to Assist Elders with
Cognitive Impairment,” AI Magazine (Summer 2005):
9–25. See also Federal Deposit InsuranceCorporation,