1. Explain how a survival curves is produced and what it means.
- graph showing the percentages of a newly
born population still alive as the age of members of the population increase
- shows death rates at different times of
the life span
- suggests degree of mortality factors at
different ages of the population
2. Describe changes in survival curves and intensity of mortality factors for U.S. populations during the twentieth century.
- dramatic decrease in childhood mortality
factors and childhood death rates early in the century
- gradual decline in mortality factors and
death rates for elders in the later half of the century
3. Describe possible changes in survival curves and their effects on the total population if there are increases in mean longevity, in maximal longevity, or in both parameters.
- increase in ML -> shift in last part of curve
(survival of adult population) to the right; results in large increase
in number of elders, in percentage of elders, and in total population
- increase in XL -> shift only the tail of
curve (survival of oldest elders) to the right; results in small increase
in number of elders, percentage of elders, and in total population
- increase in ML and in XL -> very great shift
in last part of curve (survival of adult population) to the right; results
in very large increase in number of elders, in percentage of elders, and
in total population
- increase in ML or in ML plus XL would lead
to very rapid increase in population, and possibly overpopulation
4. Discuss implications from the current increases in elders and possible additional increases if ML or if ML plus XL increase.
- examples include all aspects of individual and societal conditions (e.g., housing, food, health care, need for gerontology education, employment opportunities, career opportunities, economic conditions, political conditions, lifestyles, ecological conditions, etc.)
Return to Main Index
© Copyright 1999 - Augustine G. DiGiovanna - All rights reserved.
This material MAY be reproduced or distributed in any form or
by any means, or stored in any data base or retrieval system ONLY
under one of the following two conditions: (1) If no individual,
group, organization, institution, company, corporation or other entity
is charged for its use and only for use by instructors and students in
courses where students are required to purchase the book HUMAN AGING: BIOLOGICAL
PERSPECTIVES by Augustine G. DiGiovanna, The McGraw-Hill Companies, New
York, 1994 or 2000; (2) If prior written permission is obtained
from Augustine G. DiGiovanna.