Australasian Science: Australia's authority on science since 1938

Animal vs Human

By Tim Olds

How does the fitness of humans compare with other animals?

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If we could go back a million years and pick an evolutionary winner from the zoosphere, humans would have been pretty low on the list. Weak, small, slow of foot, poorly armed in tooth and claw, prone to internecine wars – they really didn’t have much going for them. Clearly other things counted – social groups, opposable thumbs, thermoregulation in chase hunting, upright posture on the savannah, big brains …

How do humans actually compare with animals in the fitness department? During the 1980s, C. Richard Taylor and Ewald Weibel undertook a series of experiments measuring the maximal aerobic capacity of a wide range of animals. They used techniques that could only be described as innovative – and daring.

Maximal aerobic capacity (VO2max) is the highest rate at which an organism can use oxygen to produce energy, and is the key measure of stamina. In humans, VO2max is usually expressed in millilitres of oxygen per kilogram of body weight per minute. The average VO2max for a human is about 40 mL/kg/min.

VO2max depends on what is known as “the pathway for oxygen” – the flow of oxygen from the sea of air around us down to the muscles. Based on their animal work, Taylor and Weibel developed a much-debated hypothesis called “symmorphosis” – the idea that each stage of the pathway for oxygen (lungs, heart, tissues) is functionally adapted to the other...

The full text of this article can be purchased from Informit.