Revista Chilena de Historia Natural 76 (1): 57-64, 2003
RESEARCH ARTICLE
Body mass and body weight: a dual reference system in biology
The aim of the present study was to compare two different biological similarity criteria,
one was based on body mass (M) as a theoretical reference system in accordance with the MLT-system of physics, while the other
utilized the body weight (W) for the same purpose. The mass-dependent allometry should be applied during space flights as well as
during fetal and newborn conditions of life, whereas the weight-dependence should prevail in earth-bound physiology. The above
mentioned distinctions are relevant not only for the specific metabolic rates but also for numerous biological time functions, as for
instance for the heart and respiratory rates of all mammals, whose allometric exponent is b = - 0.09 during fetal life, and b = - 0.25 in all
adult specimens.
Key words:
dimensional analysis,
biological similarity, allometry, biological time, fetal life, space physiology
