Escargots through time: an energetic comparison of marine gastropod assemblages before and after the Mesozoic Marine Revolution

Paleobiology ◽  
2011 ◽  
Vol 37 (2) ◽  
pp. 252-269 ◽  
Author(s):  
Seth Finnegan ◽  
Craig M. McClain ◽  
Matthew A. Kosnik ◽  
Jonathan L. Payne
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Net Primary Production ◽  
Average Energy ◽  
Late Triassic ◽  
Physiological Data ◽  
Marine Animal ◽  
Before And After ◽  
Per Capita ◽  
Mesozoic Marine Revolution

The modern structure of marine benthic ecosystems was largely established during the Jurassic and Early Cretaceous (200–100 Ma), a transition that has been termed the Mesozoic Marine Revolution (MMR). Although it has been suggested that the MMR marks an increase in the average energy consumption of marine animal ecosystems, this hypothesis has not been evaluated quantitatively. In this study, we integrate body size and abundance data from the fossil record with physiological data from living representatives to estimate mean per capita metabolic rates of tropical to subtropical assemblages of shallow-marine gastropods—a major component of marine ecosystems throughout the Meso-Cenozoic—both before and after the MMR. We find that mean per capita metabolic rate rose by ∼150% between the Late Triassic and Late Cretaceous and remained relatively stable thereafter. The most important factor governing the increase in metabolic rate was an increase in mean body size. In principle, this size increase could result from secular changes in sampling and taphonomic biases, but these biases are suggested to yield decreases rather than increases in mean size. Considering that post-MMR gastropod diversity is dominated by predators, the net primary production required to supply the energetic needs of the average individual increased by substantially more than 150%. These data support the hypothesis that benthic energy budgets increased during the MMR, possibly in response to rising primary productivity.

Concomitant interindividual variation in body temperature and metabolic rate

1992 ◽  
Vol 263 (4) ◽  
pp. E730-E734 ◽  
Author(s):  
R. Rising ◽  
A. Keys ◽  
E. Ravussin ◽  
C. Bogardus
Keyword(s):  
Body Composition ◽  
Body Size ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Interindividual Variation ◽  
Intraindividual Variation ◽  
Interindividual Variations ◽  
Caucasian Men ◽  
Before And After ◽  
Point Body

There is significant variation in metabolic rate in humans, independent of differences in body size, body composition, age, and gender. Although it has been generally held that the normal human "set-point" body temperature is 37 degrees C, these interindividual variations in metabolic rate also suggest possible variations in body temperature. To examine the possibility of correlations between metabolic rate and body temperature, triplicate measurements of oral temperatures were made before and after measurement of 24-h energy expenditure in a respiratory chamber in 23 Pima Indian men. Fasting oral temperatures varied more between individuals than can be attributed to methodological errors or intraindividual variation. Oral temperatures correlated with sleeping (r = 0.80, P < 0.0001), and 24-h (r = 0.48, P < 0.02) metabolic rates adjusted for differences in body size, body composition, and age. Similarly, in the 32 Caucasian men of the Minnesota Semi-Starvation Study, oral temperature correlated with adjusted metabolic rate, and the interindividual differences in body temperature were maintained throughout semistarvation and refeeding. These results suggest that a low body temperature and a low metabolic rate might be two signs of an obesity-prone syndrome in humans.

Population abundance and body size in animal assemblages

1994 ◽  
Vol 343 (1303) ◽  
pp. 33-39 ◽  
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Body Mass ◽  
Animal Species ◽  
Marine Animal ◽  
Aquatic Animal ◽  
Population Abundance ◽  
Marine Environments ◽  
Abundance Patterns ◽  
The Relationship

Studies of the relationship between body mass and population abundance for terrestrial and aquatic animal species based on pooling data from many taxa and assemblages suggest that abundance scales with mass to the —0.75 power. Because metabolic rate scales with mass as (plus) 0.75, this result has been taken as evidence that all species in assemblages use equal amounts of energy. The evidence for ‘energetic equivalence’ is, however, equivocal, because within many individual assemblages the scaling of abundance on mass differs significantly from —0.75. Here, we present a summary of patterns of size and abundance in a number of different terrestrial, freshwater and marine animal assemblages, with the aim of discovering whether there is any generality in size-abundance patterns within assemblages, and whether any generality might hold across terrestrial, freshwater and marine environments.

scholarly journals Changes in body temperature influence the scaling of and aerobic scope in mammals

2006 ◽  
Vol 3 (1) ◽  
pp. 100-103 ◽  
Author(s):  
James F Gillooly ◽  
Andrew P Allen
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Size Dependence ◽  
Maximal Activity ◽  
Scaling Exponent ◽  
Temperature Influence ◽  
Aerobic Scope ◽  
Metabolic Scope ◽  
Single Power ◽  
Maximum Metabolic Rate

Debate on the mechanism(s) responsible for the scaling of metabolic rate with body size in mammals has focused on why the maximum metabolic rate ( ) appears to scale more steeply with body size than the basal metabolic rate (BMR). Consequently, metabolic scope, defined as /BMR, systematically increases with body size. These observations have led some to suggest that and BMR are controlled by fundamentally different processes, and to discount the generality of models that predict a single power-law scaling exponent for the size dependence of the metabolic rate. We present a model that predicts a steeper size dependence for than BMR based on the observation that changes in muscle temperature from rest to maximal activity are greater in larger mammals. Empirical data support the model's prediction. This model thus provides a potential theoretical and mechanistic link between BMR and .

Mass extinctions alter extinction and origination dynamics with respect to body size

2021 ◽  
Vol 288 (1960) ◽  
Author(s):  
Pedro M. Monarrez ◽  
Noel A. Heim ◽  
Jonathan L. Payne
Keyword(s):  
Body Size ◽  
Mass Extinction ◽  
Evolutionary Biology ◽  
Marine Animal ◽  
Mass Extinctions ◽  
Extinction Selectivity ◽  
Extinction Events ◽  
Mass Extinction Events ◽  
Marine Biosphere

Whether mass extinctions and their associated recoveries represent an intensification of background extinction and origination dynamics versus a separate macroevolutionary regime remains a central debate in evolutionary biology. The previous focus has been on extinction, but origination dynamics may be equally or more important for long-term evolutionary outcomes. The evolution of animal body size is an ideal process to test for differences in macroevolutionary regimes, as body size is easily determined, comparable across distantly related taxa and scales with organismal traits. Here, we test for shifts in selectivity between background intervals and the ‘Big Five’ mass extinction events using capture–mark–recapture models. Our body-size data cover 10 203 fossil marine animal genera spanning 10 Linnaean classes with occurrences ranging from Early Ordovician to Late Pleistocene (485–1 Ma). Most classes exhibit differences in both origination and extinction selectivity between background intervals and mass extinctions, with the direction of selectivity varying among classes and overall exhibiting stronger selectivity during origination after mass extinction than extinction during the mass extinction. Thus, not only do mass extinction events shift the marine biosphere into a new macroevolutionary regime, the dynamics of recovery from mass extinction also appear to play an underappreciated role in shaping the biosphere in their aftermath.

Respiratory Exchange and Body Size in the Aldabra Giant Tortoise

1971 ◽  
Vol 55 (3) ◽  
pp. 651-665 ◽  
Author(s):  
G. M. HUGHES ◽  
R. GAYMER ◽  
MARGARET MOORE ◽  
A. J. WOAKES
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Metabolic Rate ◽  
Relative Proportion ◽  
The Body ◽  
O2 Consumption ◽  
Weight Range ◽  
Testudo Hermanni ◽  
The Mean ◽  
Good Agreement

1. The O2 consumption and CO2 release of nine giant tortoises Testudo gigantea (weight range 118 g-35·5 kg) were measured at a temperature of about 25·5°C. Four European tortoises Testudo hermanni (weight range 640 g-2·16 kg) were also used. The mean RQ values obtained were 1·01 for T. gigantea and 0·97 for T. hermanni. These values were not influenced by activity or size. 2. The data was analysed by plotting log/log regression lines relating body weight to O2 consumption. Both maximum and minimum metabolic rates recorded for each individual T. gigantea showed a negative correlation with body weight. For active rates the relation was O2 consumption = 140·8W0·97, whereas for inactive animals O2 consumption = 45·47W0·82. 3. The maximum rates were obtained from animals that were observed to be active in the respirometer and the minimum rates from animals that remained quiet throughout. The scope for activity increased with body size, being 82 ml/kg/h for animals of 100 g and 103 ml/kg/h for 100 kg animals. The corresponding ratio between maximum and minimum rates increases from about 2 to 6 for the same weight range. 4. Values for metabolic rate in T. hermanni seem to be rather lower than in T. gigantea. Analysis of the relative proportion of the shell and other organs indicates that the shell forms about 31% of the body weight in adult T. hermanni but only about 18% in T. gigantea of similar size. The shell is not appreciably heavier in adult T. gigantea (about 20%). 5. Data obtained for inactive animals is in good agreement with results of other workers using lizards and snakes. Previous evidence suggesting that chelonians show no reduction in metabolic rate with increasing size is not considered to conflict with data obtained in the present work.

scholarly journals Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers

1996 ◽  
Vol 81 (5) ◽  
pp. 1901-1907 ◽  
Author(s):  
Roland Favier ◽  
Esperanza Caceres ◽  
Laurent Guillon ◽  
Brigitte Sempore ◽  
Michel Sauvain ◽  
...  
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Metabolic Responses ◽  
Physiological Data ◽  
Respiratory Gas Exchange ◽  
Gum Chewing ◽  
Arterial Blood ◽  
Before And After ◽  
Exercise Induced

Favier, Roland, Esperanza Caceres, Laurent Guillon, Brigitte Sempore, Michel Sauvain, Harry Koubi, and Hilde Spielvogel. Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers. J. Appl. Physiol. 81(5): 1901–1907, 1996.—To determine the effects of acute coca use on the hormonal and metabolic responses to exercise, 12 healthy nonhabitual coca users were submitted twice to steady-state exercise (∼75% maximal O2 uptake). On one occasion, they were asked to chew 15 g of coca leaves 1 h before exercise, whereas on the other occasion, exercise was performed after 1 h of chewing a sugar-free chewing gum. Plasma epinephrine, norepinephrine, insulin, glucagon, and metabolites (glucose, lactate, glycerol, and free fatty acids) were determined at rest before and after coca chewing and during the 5th, 15th, 30th, and 60th min of exercise. Simultaneously to these determinations, cardiorespiratory variables (heart rate, mean arterial blood pressure, oxygen uptake, and respiratory gas exchange ratio) were also measured. At rest, coca chewing had no effect on plasma hormonal and metabolic levels except for a significantly reduced insulin concentration. During exercise, the oxygen uptake, heart rate, and respiratory gas exchange ratio were significantly increased in the coca-chewing trial compared with the control (gum-chewing) test. The exercise-induced drop in plasma glucose and insulin was prevented by prior coca chewing. These results contrast with previous data obtained in chronic coca users who display during prolonged submaximal exercise an exaggerated plasma sympathetic response, an enhanced availability and utilization of fat (R. Favier, E. Caceres, H. Koubi, B. Sempore, M. Sauvain, and H. Spielvogel. J. Appl. Physiol. 80: 650–655, 1996). We conclude that, whereas coca chewing might affect glucose homeostasis during exercise, none of the physiological data provided by this study would suggest that acute coca chewing in nonhabitual users could enhance tolerance to exercise.

Transoral Radiofrequency Treatment of Snoring

2002 ◽  
Vol 127 (3) ◽  
pp. 235-237 ◽  
Author(s):  
Jonas T. Johnson ◽  
Gabrielle L. Pollack ◽  
Robin L. Wagner
Keyword(s):  
Soft Palate ◽  
Average Energy ◽  
Response To Therapy ◽  
Inadequate Response ◽  
Significant Other ◽  
Viable Option ◽  
Insufficient Amount ◽  
Patient Tolerance ◽  
Before And After ◽  
Number Of Treatment

OBJECTIVES/HYPOTHESIS: Radiofrequency ablation (RFA) may effectively treat snoring with acceptable patient tolerance. STUDY DESIGN: A cohort of patients with unacceptable snoring underwent RFA to the soft palate between October 1997 and May 2000. Before the therapy, a family member or significant other person was interviewed to rate snoring loudness. METHODS: Snoring was rated on a visual analog scale of 0 to 10 (in which 0 was no snoring and 10 was horrific snoring) before and after therapy. All patients were treated with transoral RFA administered under local anesthesia at 6-week intervals. RESULTS: Complete data were available for 60 of the 75 treated patients. The average number of treatment sessions per patient was 1.8. These patients received an average energy of 1845 J. Overall the average snoring score was 8.9 before therapy and 3.5 after therapy. Fifty-one patients (85%) were considered to have major improvement in snoring loudness. A total of 9 patients (15%) were nonresponders. CONCLUSIONS: RFA to the soft palate is a viable option to treat socially unacceptable snoring. Inadequate response to therapy may reflect misdiagnosis or delivery of an insufficient amount of energy.

Relation between Metabolic Rate and Body Size in the Ovine Fetus

1987 ◽  
Vol 117 (6) ◽  
pp. 1181-1186 ◽  
Author(s):  
Alan W. Bell ◽  
Frederick C. Battaglia ◽  
Giacomo Meschia
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Ovine Fetus
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