No | Arguments | Refutations |
7.1 | O’Dor and Hoar (158) claimed that “There is a fundamental flaw in examining Pauly’s surface area limited growth scheme by plotting two different sets of units (m2 and m3) on the same graph and then making quantitative conclusions. Not only is [the resulting figure] messy, it violates a rule of physics and engineering (179).” The rule alluded to here is probably “For an equation to have any applicability to the real world, not only must the two sides by numerically equal, but they must also be dimensionally equal” (179). | The GOLT involves no equation with dimensionally unequal sides. Its presentation, however, may include graphs with two ordinates axes with different units, as illustrated on figure 6.8, p. 96 of the reference cited here (179). This reference is therefore not likely to have suggested that such figures violate the rules of physics and engineering. In fact, plots with two (or more) ordinate scales are common in science (180). The key issue, in any case, is that anything proportional to the third power of length will outgrow anything that remains proportional to a lower power of length, whatever the units and the starting values. |
7.2 | It was claimed (42) that in in the contribution of Cheung et al. (7), the GOLT predicted a strong size reduction of fish with temperature because a key parameter was deliberately set too low (d = 0.7) | When the parameter in question was set at higher values (d = 0.8 to 0.9), the size reduction caused by increasing temperature actually increased (54). |
7.3 | That ecophysiological consideration should not be used to explain physiological processes was asserted in a contribution (181) that criticizes Pörtner et al.’s “oxygen and capacity limited temperature tolerance” (OCLTT) hypothesis, which partly overlaps with the GOLT (169, 182, 183). | No biological subdiscipline can assume a priori a monopoly in answering a specific scientific question. In fact, scientific problems are nowadays best tackled using interdisciplinary approaches (184). Pörtner et al. (183) suggest that “to connect closely to ecological changes, studies need to consider the long-term consequences of subtle functional constraints. […] Indeed, such requirements are rarely met in purely physiological studies.” |
7.4 | Jutfelt et al. (181) suggest that Pörtner et al.’s OCLTT hypothesis “incorrectly [considers] aerobic scope or oxygen delivery capacity as the ‘energy’ available to animals, when in fact it is only a permissive factor compared with other constraints (e.g., food availability).” | Animals, including fish, deprived of oxygen die within minutes. In addition, the chemical energy embodied in their food becomes available to them only when that food is combined with oxygen, i.e., burnt. Thus, considering oxygen to be one of several “permissive” factors of metabolism to score a few points against a colleague takes us back to the times before the discoveries of Lavoisier (1743–1784). |
7.5 | Here is another argument against Pörtner et al.’s OCLTT hypothesis “it is hard to imagine why animals would allow tissue hypoxia to become severe enough to inflict performance decline at moderate levels of activity when possessing the functional capacity to significantly increase oxygen delivery to tissues” (181). | That none of the 28 authors of that contribution could imagine why animal cannot operate all the time at peak performance is itself hard to imagine, but it bears repeating here: Peak performance extracts a massive toll on all organ systems and is used only to escape predators or life-threatening situations (17, 185). Repeated peak performance, as forced in experiments, renders the tested animals unfit for life in the wild. |
7.6 | The closing argument (42): “The idea that insurmountable geometric constraints on the size of the gills could determine the metabolic rate of fishes has never, as far as we know, been pursued as a valid hypothesis among respiratory physiologists. It is for example not mentioned in Schmidt-Nielsen or in Evans and Clairborne, two sources for overviews of animals and fish physiology.” | This meta-argument about the authority of textbooks (186, 187) is a strange one to make in the 21st century, although it could have been made in the Middle Ages with reference to species not mentioned in Aristotle’s Historia Animalium (188) or in the writings of Plinius the Elder (189). |