Document Detail


The matches, achieved by natural selection, between biological capacities and their natural loads.
MedLine Citation:
PMID:  1612134     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Natural selection tends to eliminate unutilized capacities because of their costs. Hence we ask how large are the reserve capacities by which biological capacities exceed natural loads, and how closely are related biological capacities matched to each other. Measured capacities (Vmax values) of small intestinal brush-border nutrient transporters are typically around twice their natural loads (dietary intakes of their substrates); the ratio is higher for a transporter of a hyperessential nutrient. Preliminary evidence suggests matching of capacities between different steps in carbohydrate metabolism, and between the intestine, liver, kidneys, and spleen. Symmorphosis - the postulated matching of capacities to each other and to loads - is a testable hypothesis of economic design, useful in detecting and explaining cases of apparently uneconomic design.
Authors:
J Diamond; K Hammond
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Experientia     Volume:  48     ISSN:  0014-4754     ISO Abbreviation:  Experientia     Publication Date:  1992 Jun 
Date Detail:
Created Date:  1992-07-30     Completed Date:  1992-07-30     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  0376547     Medline TA:  Experientia     Country:  SWITZERLAND    
Other Details:
Languages:  eng     Pagination:  551-7     Citation Subset:  IM    
Affiliation:
Department of Physiology, University of California Medical School, Los Angeles 90024-1751.
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MeSH Terms
Descriptor/Qualifier:
Animals
Carrier Proteins / metabolism
Cold Temperature
Dietary Carbohydrates / metabolism
Female
Hydrolases / metabolism
Intestinal Absorption*
Intestine, Small / metabolism
Lactation
Mice
Microvilli / metabolism
Models, Biological
Pregnancy
Selection, Genetic*
Grant Support
ID/Acronym/Agency:
DK 42973/DK/NIDDK NIH HHS; GM 14772/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
0/Carrier Proteins; 0/Dietary Carbohydrates; EC 3.-/Hydrolases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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