Although bipedalism is unusual, humans are not the only living bipeds. For example, some flightless birds are also bipedal. Identify a living nonprimate animal that is also a biped. Then, compare its bipedalism to our biped-alism.

Explanation:

Human and birds as the basis for comparison. Some birds walk and run with their backs and femurs tilting at small angles to the horizontal and with bent knees while most human walk uprightly with legs straight and this can be seen in the duty and task performed by man.

Humans exert on the ground while walking two-peaked pattern of force which makes some human work very fast but Birds do not exact two-peaked pattern of force.

Human walking for individual with same body mass is relatively economical of metabolic energy while Bipedal locomotion is economical for wading birds, it is expensive for geese and penguins.