Biodemography of Human Longevity

Leonid Gavrilov

Center on Aging, NORC and the University of Chicago

(Abstract of keynote lecture at the International Conference on Longevity, Sydney, Australia, March 5-7, 2004)

Biodemography is a multidisciplinary approach, integrating biological knowledge (studies on human biology and animal models) with demographic research on human longevity and survival.   Biodemographic studies are important for understanding the driving forces of current longevity revolution (dramatic increase in human life expectancy),  forecasting the future of human longevity, and identification of new strategies for further increase in healthy and productive life span.

Biodemographic studies found a remarkable similarity in survival dynamics between humans and laboratory animals.   Specifically, three general biodemographic laws of survival are found: 

(1) Gompertz-Makeham law of mortality; 
(2) Compensation law of mortality,  and  
(3) Late-life mortality deceleration. 

The Gompertz-Makeham law states that death rate is a sum of age-independent component (Makeham term) and age-dependent component (Gompertz function), which increases exponentially with age. 

The Compensation law of mortality (late-life mortality convergence) states that the relative differences in death rates between different populations of the same biological species are decreasing with age, because the higher initial death rates are compensated by lower pace of their increase with age. 

The Late-life mortality deceleration law states that death rates stop to increase exponentially at advanced ages and level-off to the late-life mortality plateau.  An immediate consequence from this observation is that there is no fixed upper limit to human longevity - there is no special fixed number, which separates possible and impossible values of lifespan.  This conclusion is important, because it challenge the common belief in existence of a fixed maximal human life span.

Biodemographic studies found that even genetically identical laboratory animals kept in constant environment have very different lengths of life, suggesting a crucial role of chance and early-life developmental noise in longevity determination.  This leads to new approaches in understanding causes of exceptional human longevity.

As for the future of human longevity, it is important to understand that longevity revolution had two very distinct stages – the initial stage of mortality decline at younger ages is now replaced by a new trend of preferential improvement of the oldest-old survival. This phenomenon invalidates methods of longevity forecasting based on extrapolation of long-term historical trends.

Finally, a general explanation of aging and longevity is suggested based on system reliability theory.

Click here for Power Point Presentation (4Mb).

The Conference organizers selected this keynote lecture with two other lectures (one by a representative from the United Nations, and another by a representative from the World Health Organization) for a world-wide distribution in the form of DVD  (DVD04_01).

Relevant Publications:

1. Gavrilov L.A., Gavrilova N.S. The Biology of Life Span: A Quantitative Approach, NY: Harwood Academic Publisher, 1991, 385p.

2. Gavrilov L.A., Gavrilova N.S. The quest for a general theory of aging and longevity.  Science's SAGE KE (Science of Aging Knowledge Environment) for 16 July 2003; Vol. 2003, No. 28, 1-10.

3. Gavrilov L.A., Gavrilova N.S., Olshansky S.J., Carnes B.A. Genealogical data and biodemography of human longevity. Social Biology, 2002, 49(3-4): 160-173.

4. Gavrilov, L.A., Gavrilova, N.S. Biodemographic study of familial determinants of human longevity. Population: An English Selection, 2001, 13(1): 197-222.

5. Gavrilova, N.S., Gavrilov, L.A. Data resources for biodemographic studies on familial clustering of human longevity.  Demographic Research [Online], 1999, vol.1(4): 1-48. Available:

6. Gavrilova, N.S., Gavrilov, L.A., Evdokushkina G.N., Semyonova, V.G., Gavrilova, A.L., Evdokushkina, N.N., Kushnareva, Yu.E., Kroutko, V.N., Andreyev, A.Yu.  Evolution, mutations and human longevity. Human Biology, 1998, 70(4): 799-804.

7. Gavrilov, L.A., Gavrilova, N.S. Fruit fly aging and mortality. Letter,  Science, 1993, 260(5114): 1565-1565.

8. Gavrilov, L. A. Biodemographic aspects of life span studies. In: Demographic Studies,  Moscow: Moscow State Univ. Press, 1988, 105-121.

9. Gavrilov, L.A., Gavrilova, N.S., Yaguzhinsky, L.S. The main regularities of animal aging and death viewed in terms of reliability theory. J. General Biology [Zhurnal Obschey Biologii], 1978, 39(5): 734-742.

This keynote lecture received an average score of 4.21 out of 5.00 maximum possible points in its anonymous evaluation conducted by the Organizing Committee among the Conference participants.

Some comments include:

-- "Great to see such a dedicated, warm scientist."

-- "Amazing!  We consider a genetic reason for everything. Every aspect has to be considered."

-- "Content was fascinating & pitched at an intelligent level - Great!!"