• Publications
  • Influence
An allometric analysis of the giraffe cardiovascular system.
  • G. Mitchell, J. Skinner
  • Medicine, Biology
    Comparative biochemistry and physiology. Part A…
  • 1 December 2009
Adaptive heterothermy and selective brain cooling in arid-zone mammals.
On the origin, evolution and phylogeny of giraffes Giraffa camelopardalis
It is concluded that the proximate ancestors of modern giraffes probably evolved in southern central Europe about 8 million years ago and may have arisen from the gelocid ancestral assemblage of 20–25 Mya via the family Palaeomerycidae.
Brain, abdominal and arterial blood temperatures of free-ranging eland in their natural habitat
The results do not support the concept that eland routinely employ adaptive heterothermy and selective brain cooling to survive in their natural environment.
Brain and arterial blood temperatures of free-ranging oryx (Oryx gazella)
It is concluded that, contrary to the widely cited postulate, the carotid rete does not protect the brain during hyperthermia, and Oryx also do not show adaptive heterothermy and, over short time intervals, have a brain temperature more variable than carOTid blood temperature.
Harvey Cushing and the regulation of blood pressure in giraffe, rat and man: introducing ‘Cushing's mechanism’
It is proposed that a common link could be reduced brainstem perfusion, as first suggested by Cushing in 1901, and suggested that future successful treatment of essential hypertension in man will include methods of reducing cerebral arterial resistance.
Absence of Selective Brain Cooling in Free‐Ranging Zebras in Their Natural Habitat
The results do not support the view that mammals lacking a carotid rete can achieve selective brain cooling, and the relationship between brain and arterial blood temperatures in free‐ranging zebras was unlike that reported for horses in the laboratory.
Guttural pouches, brain temperature and exercise in horses
It is concluded that cerebral blood flow removes heat from the brain by convection, but since SBC does not occur in horses, the guttural pouches are not surrogate carotid retes.
Sexual selection is not the origin of long necks in giraffes
It is concluded that morphological differences between males and females are minimal, that differences that do exist can be accounted for by the larger final mass of males and that sexual selection is not the origin of a long neck in giraffes.
A year in the thermal life of a free-ranging herd of springbok Antidorcas marsupialis
Annual and daily variations in body temperature of springbok appear to reflect an endogenous rhythm, entrained by the light:dark cycle, but largely independent of fluctuations in the environmental thermal load.