. The biology of senescence. Old age; Aging; Longevity. The Biology of Senescence Hereditary factors in human longevity have often been sought. Pearl and Pearl (1934a, b) found, for instance, that the summed ages at death of the six immediate ancestors of centen- arians and nonagenarians were significantly greater than in a control series of the relatives of individuals not selected for longevity. 86-6 per cent of long-lived (> 70) subjects had at least one long-lived parent, while 48-5 per cent of nonagenarians 60- 60 : 40 u 20 -. i i i i I i i i i i I i i i i iir'rff'l | <"i 24 mo
. The biology of senescence. Old age; Aging; Longevity. The Biology of Senescence Hereditary factors in human longevity have often been sought. Pearl and Pearl (1934a, b) found, for instance, that the summed ages at death of the six immediate ancestors of centen- arians and nonagenarians were significantly greater than in a control series of the relatives of individuals not selected for longevity. 86-6 per cent of long-lived (> 70) subjects had at least one long-lived parent, while 48-5 per cent of nonagenarians 60- 60 : 40 u 20 -. i i i i I i i i i i I i i i i iir'rff'l | <"i 24 monfhl Fig. 31.—Survival curves of mice in laboratory culture—breeding females. Curve A based on 241 dba females, curve B on 730 Bittner albinos, curve C, on 1350 Marsh albinos (from Gruneberg, 1951). and 53-4 per cent of centenarians had two such parents, all these figures being significantly higher than in the control series. Kallman and Sander (1948, 1949) found that in 1062 pairs of twins the mean difference in longevity between dizygotic twin individuals was twice as great as in monozygotics. These and other studies indicate that longevity is 'hereditary', but un- fortunately give little light on its genetics. Beeton and Pearson (1901) studied the longevity records of Quaker families, and found that the sib-sib correlation of longevity was nearly twice the parent-offspring correlation, in those individuals who died 122. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Comfort, Alex, 1920-. New York, Rinehart
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Keywords: ., bookcentury1900, booksub, booksubjectlongevity, booksubjectoldage
