. 2012 Jun 6;279(1742):3616–3621. doi: 10.1098/rspb.2012.0884

Table 1.

Akaike's information criterion (AIC) for a candidate set of models that explain variation in metabolic rate (MR) in terms of body mass (M) and temperature (T); where E is activation energy, b is the scaling exponent and Q₁₀ (the factorial increase in MR associated with a 10°C increase in temperature) is calculated as e^10c. (The best model is the one with the lowest AIC, and the probability that a given model provides the best fit of those tested is provided by its Akaike weight, w_i.)

model	scaling exponent, b	temperature dependence	interaction between mass and temperature	AIC	w_i
MR = i₀ M^b e^cT	estimated, varies^a	Q₁₀, varies^a		−1139	0.37
MR = i₀ M^b e^−E/kT	estimated, varies^a	UTD, varies^a		−1139	0.34
MR = i₀ M^b e^cT	estimated, varies^a	Q₁₀, varies^a	lnM × Q₁₀	−1137	0.14
MR = i₀ M^b e^−E/kT	estimated, varies^a	UTD, varies^a	lnM × UTD	−1137	0.13
MR = i₀ M^b e^cT	estimated, varies^a	Q₁₀, constant^b		−1133	0.02
MR = i₀ M^b e^−E/kT	estimated, varies^a	UTD, constant^b		−1127	0.001
MR = i₀ M^b e^cT	estimated, constant^b	Q₁₀, varies^a		−1025	<0.0001
MR = i₀ M^b e^−E/kT	estimated, constant^b	UTD, varies^a		−1024	<0.0001
MR = i₀ M^b e^cT	estimated, constant^b	Q₁₀, constant^b		−1015	<0.0001
MR = i₀ M^b e^−E/kT	estimated, constant^b	UTD, constant^b		−1010	<0.0001
MR = i₀ M^b e^−E/kT	fixed^c: 0.75	UTD, constant^b		−982	<0.0001
MR = i₀ M^3/4 e^{−7.4(1000/T)}	fixed^c: 0.75	UTD, fixed^d: −7.4		−957	<0.0001

^aScaling exponent or temperature fitted separately for each group. Note that temperature is in Kelvin for UTD and degrees Celsius for Q₁₀.

^bScaling exponent or temperature dependence constant between groups.

^cFixed at three-fourth for all groups following theoretical predictions [11,12] and the fundamental equation of MTE [6,7].

^dFixed at −7.4 K for all groups based on an average activation energy for metabolic reactions of 0.6 eV, following MTE [6,7].