To reply to a digest, insert the relevant message header; don't reply to the digest header
-------------------------------------------------------------

I haven't gotten the full-text yet, but this article really seems to
support our view of evolutionary fitness.

----------------------------------------------------------------------------
----

J Appl Physiol 96: 3-10, 2004; 10.1152/japplphysiol.00757.2003

8750-7587/04


INVITED REVIEW


Eating, exercise, and "thrifty" genotypes: connecting the dots toward an
evolutionary understanding of modern chronic diseases


Manu V. Chakravarthy1 and Frank W. Booth2

1Division of Endocrinology, Metabolism and Lipid Research, Department of
Internal Medicine, Washington University School of Medicine, St. Louis
63110; and 2Departments of Biomedical Sciences and of Medical Pharmacology
and Physiology and the Dalton Cardiovascular Institute, University of
Missouri, Columbia, Missouri 65211



Survival of Homo sapiens during evolution was dependent on the procurement
of food, which in turn was dependent on physical activity. However, food
supply was never consistent. Thus it is contended that the ancient hunter-
gatherer had cycles of feast and famine, punctuated with obligate periods
of physical activity and rest. Hence, gene selection in the Late-
Paleolithic era was probably influenced by physical activity and rest. To
ensure survival during periods of famine, certain genes evolved to regulate
efficient intake and utilization of fuel stores. Such genes were
termed "thrifty genes" in 1962. Furthermore, convincing evidence shows that
this ancient genome has remained essentially unchanged over the past 10,000
years and certainly not changed in the past 40-100 years. Although the
absolute caloric intake of modern-day humans is likely lower compared with
our hunter-gatherer ancestors, it is nevertheless in positive caloric
balance in the majority of the US adult population mainly due to the
increased sedentary lifestyle in present society. We contend that the
combination of continuous food abundance and physical inactivity eliminates
the evolutionarily programmed biochemical cycles emanating from feast-
famine and physical activity-rest cycles, which in turn abrogates the
cycling of certain metabolic processes, ultimately resulting in metabolic
derangements such as obesity and Type 2 diabetes. In this context, we
postulate that perhaps a crucial mechanism to break the stall of the
metabolic processes would be via exercise through the regulation
of "physical activity genes," some of which may also be potential
candidates for the "thrifty genes" of our hunter-gatherer ancestors.
Therefore, the identification of such "thrifty gene" candidates would help
provide insight into the pathogenetic processes of the numerous physical
inactivity-mediated disorders.

-----------------------------------------------------------------
The FAQ for Evolutionary Fitness is at http://www.evfit.com/faq.htm
To unsubscribe from the list send an e-mail to [log in to unmask]
with the words SIGNOFF EVOLUTIONARY-FITNESS in the _body_ of the e-mail.