THAT'S THE WHY:We humans are particularly toasty creatures, maintaining a normal body temperature of about 37 degrees, give or take a smidgen, but why do we need to keep the internal furnace lit at just this level?
One interesting theory is that our bodies run at about this temperature as a trade-off to help keep disease-causing fungi at bay without putting the metabolic cost of the heating bill through the roof.
“We posited that increases in body temperature would protect against microbes by creating a thermal exclusionary zone but that such increases would be increasingly costly with regard to metabolic rates as the host body temperature diverged from ambient temperatures,” wrote researchers at the Albert Einstein College of Medicine in New York last year in mBio, an open-access journal from the American Society for Microbiology.
They went on to lay out a mathematical model for this scenario, concluding that “a body temperature of 36.7°C maximises fitness by restricting the growth of most fungal species relative to its metabolic cost”.
One of the authors on the study, Arturo Casadevall – who, incidentally, is founding editor-in-chief of mBio – has also suggested that fungi may even have been linked with dinosaur extinction and the rise of mammals.
“Deforestation and proliferation of fungal spores at cretaceous-tertiary boundary suggests that fungal diseases could have contributed to the demise of dinosaurs and the flourishing of mammalian species,” he wrote in a 2004 paper in the journal Fungal Genetics and Biology.
