Scaling of Metabolic Scaling within Physical Limits
Both the slope and elevation of scaling relationships between log metabolic rate and log body size vary taxonomically and in relation to physiological or developmental state, ecological lifestyle and environmental conditions. Here I discuss how the recently proposed metabolic-level boundaries hypoth...
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| Format: | Article |
| Language: | English |
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MDPI AG
2014-10-01
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| Series: | Systems |
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| Online Access: | http://www.mdpi.com/2079-8954/2/4/425 |
| _version_ | 1798034557273899008 |
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| author | Douglas S. Glazier |
| author_facet | Douglas S. Glazier |
| author_sort | Douglas S. Glazier |
| collection | DOAJ |
| description | Both the slope and elevation of scaling relationships between log metabolic rate and log body size vary taxonomically and in relation to physiological or developmental state, ecological lifestyle and environmental conditions. Here I discuss how the recently proposed metabolic-level boundaries hypothesis (MLBH) provides a useful conceptual framework for explaining and predicting much, but not all of this variation. This hypothesis is based on three major assumptions: (1) various processes related to body volume and surface area exert state-dependent effects on the scaling slope for metabolic rate in relation to body mass; (2) the elevation and slope of metabolic scaling relationships are linked; and (3) both intrinsic (anatomical, biochemical and physiological) and extrinsic (ecological) factors can affect metabolic scaling. According to the MLBH, the diversity of metabolic scaling relationships occurs within physical boundary limits related to body volume and surface area. Within these limits, specific metabolic scaling slopes can be predicted from the metabolic level (or scaling elevation) of a species or group of species. In essence, metabolic scaling itself scales with metabolic level, which is in turn contingent on various intrinsic and extrinsic conditions operating in physiological or evolutionary time. The MLBH represents a “meta-mechanism” or collection of multiple, specific mechanisms that have contingent, state-dependent effects. As such, the MLBH is Darwinian in approach (the theory of natural selection is also meta-mechanistic), in contrast to currently influential metabolic scaling theory that is Newtonian in approach (i.e., based on unitary deterministic laws). Furthermore, the MLBH can be viewed as part of a more general theory that includes other mechanisms that may also affect metabolic scaling. |
| first_indexed | 2024-04-11T20:45:53Z |
| format | Article |
| id | doaj.art-00e4ef0a5a3e44b58fdcd04f44a4b31b |
| institution | Directory Open Access Journal |
| issn | 2079-8954 |
| language | English |
| last_indexed | 2024-04-11T20:45:53Z |
| publishDate | 2014-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Systems |
| spelling | doaj.art-00e4ef0a5a3e44b58fdcd04f44a4b31b2022-12-22T04:04:02ZengMDPI AGSystems2079-89542014-10-012442545010.3390/systems2040425systems2040425Scaling of Metabolic Scaling within Physical LimitsDouglas S. Glazier0Department of Biology, Juniata College, Huntingdon, PA 16652, USABoth the slope and elevation of scaling relationships between log metabolic rate and log body size vary taxonomically and in relation to physiological or developmental state, ecological lifestyle and environmental conditions. Here I discuss how the recently proposed metabolic-level boundaries hypothesis (MLBH) provides a useful conceptual framework for explaining and predicting much, but not all of this variation. This hypothesis is based on three major assumptions: (1) various processes related to body volume and surface area exert state-dependent effects on the scaling slope for metabolic rate in relation to body mass; (2) the elevation and slope of metabolic scaling relationships are linked; and (3) both intrinsic (anatomical, biochemical and physiological) and extrinsic (ecological) factors can affect metabolic scaling. According to the MLBH, the diversity of metabolic scaling relationships occurs within physical boundary limits related to body volume and surface area. Within these limits, specific metabolic scaling slopes can be predicted from the metabolic level (or scaling elevation) of a species or group of species. In essence, metabolic scaling itself scales with metabolic level, which is in turn contingent on various intrinsic and extrinsic conditions operating in physiological or evolutionary time. The MLBH represents a “meta-mechanism” or collection of multiple, specific mechanisms that have contingent, state-dependent effects. As such, the MLBH is Darwinian in approach (the theory of natural selection is also meta-mechanistic), in contrast to currently influential metabolic scaling theory that is Newtonian in approach (i.e., based on unitary deterministic laws). Furthermore, the MLBH can be viewed as part of a more general theory that includes other mechanisms that may also affect metabolic scaling.http://www.mdpi.com/2079-8954/2/4/425body sizecontingencydevelopmental and physiological stateecological lifestyleenvironmental conditionsevolutionary adaptationmetabolismmeta-mechanismphysical constraintsscaling |
| spellingShingle | Douglas S. Glazier Scaling of Metabolic Scaling within Physical Limits Systems body size contingency developmental and physiological state ecological lifestyle environmental conditions evolutionary adaptation metabolism meta-mechanism physical constraints scaling |
| title | Scaling of Metabolic Scaling within Physical Limits |
| title_full | Scaling of Metabolic Scaling within Physical Limits |
| title_fullStr | Scaling of Metabolic Scaling within Physical Limits |
| title_full_unstemmed | Scaling of Metabolic Scaling within Physical Limits |
| title_short | Scaling of Metabolic Scaling within Physical Limits |
| title_sort | scaling of metabolic scaling within physical limits |
| topic | body size contingency developmental and physiological state ecological lifestyle environmental conditions evolutionary adaptation metabolism meta-mechanism physical constraints scaling |
| url | http://www.mdpi.com/2079-8954/2/4/425 |
| work_keys_str_mv | AT douglassglazier scalingofmetabolicscalingwithinphysicallimits |