Book contents
- Frontmatter
- Contents
- Preface
- 1 The size of living things
- 2 Problems of size and scale
- 3 The use of allometry
- 4 How to scale eggs
- 5 The strength of bones and skeletons
- 6 Metabolic rate and body size
- 7 Warm-blooded vertebrates: What do metabolic regression equations mean?
- 8 Organ size and tissue metabolism
- 9 How the lungs supply enough oxygen
- 10 Blood and gas transport
- 11 Heart and circulation
- 12 The meaning of time
- 13 Animal activity and metabolic scope
- 14 Moving on land: running and jumping
- 15 Swimming and flying
- 16 Body temperature and temperature regulation
- 17 Some important concepts
- Appendixes
- References
- Index
3 - The use of allometry
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- Preface
- 1 The size of living things
- 2 Problems of size and scale
- 3 The use of allometry
- 4 How to scale eggs
- 5 The strength of bones and skeletons
- 6 Metabolic rate and body size
- 7 Warm-blooded vertebrates: What do metabolic regression equations mean?
- 8 Organ size and tissue metabolism
- 9 How the lungs supply enough oxygen
- 10 Blood and gas transport
- 11 Heart and circulation
- 12 The meaning of time
- 13 Animal activity and metabolic scope
- 14 Moving on land: running and jumping
- 15 Swimming and flying
- 16 Body temperature and temperature regulation
- 17 Some important concepts
- Appendixes
- References
- Index
Summary
Biological significance and statistical significance
Properly calculated allometric equations (or regression lines) will be accompanied by statistics that give information about significance and confidence limits. Statistics are necessary because we cannot rely on subjective evaluations of whether or not data and numbers are significant.
Allometric equations, y = axb (or corresponding linear-regression lines), have two important numerical terms: the proportionality coefficient a (the intercept at unity) and the exponent b (the slope of the regression line). These two terms have different meanings and can answer different questions. An example will help.
The proportionality coefficient can be used to answer questions such as this: Do marsupials, in general, have lower metabolic rates than eutherian mammals (see p. 64)? The equations for the metabolic rates of these two groups have the same exponent, and we can therefore directly compare the proportionality coefficients, which are lower for marsupials. This tells us that marsupials, in general, have lower metabolic rates than eutherian mammals. The exponent, on the other hand, tells us that the metabolic rate changes with changing body size in the same way in marsupials and eutherian mammals. This suggests that the same principles determine the scaling of metabolic rates in the two groups (although the coefficient told us that the levels of their metabolic rates differ systematically).
- Type
- Chapter
- Information
- ScalingWhy is Animal Size so Important?, pp. 21 - 32Publisher: Cambridge University PressPrint publication year: 1984
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