Table 1. Characteristics of Apes and Humans





Bent over or quadrupedal "knuckle-walking" common

Upright or bipedal

Leg and arm length

Arms longer than legs; arms adapted for swinging, usually among trees

Legs usually longer than arms; legs adapted for striding


Low arches; opposable big toes, capable of grasping

High arches; big toes in line with other toes; adapted for walking


Prominent teeth; large gaps between canines and nearby teeth

Reduced teeth; gaps reduced or absent


Bent forward from spinal column; rugged surface; prominent brow ridges

Held upright on spinal column; smooth surface


Sloping; jaws jut out; wide nasal opening

Vertical profile; distinct chin; narrow nasal opening

Brain size

280 to 705 cm3 (living species)

400 to 2000 cm3 (fossil to present)

Age at puberty

Usually 10 to 13 years

Usually 13 years or older

Breeding season

Estrus at various times


Figure 1. Evolutionary relationships among organisms derived from comparisons of skeletons and other characteristics

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