CREATION BY EVOLUTION
swift running in order to catch the small animals on which it lived and to escape from its enemies. It therefore began to run on its hind legs like a kangaroo. There are only two ways in which it could maintain such a bipedal gait—either by carrying its body upright or by having a long tail to balance the head and body. The bird ancestor adopted the latter plan. It had originally a spraddling walk, the feet being turned out and kept far apart. This gait made necessary a foot like that of a lizard, in which the big toe is the shortest and the fourth toe much the longest, so that the claws all lie on a straight line, at right angles to the direction of the movement of the body. The increase in the length of the toes is gained by an increase in the number of bones or joints that support them; the first has two joints, the next three, and so on, the fourth having five.
Any animal that must run fast must draw up its feet until they lie under the body, and at the same time the foot must be so shaped that the middle toe becomes the longest and the second and fourth, which lie on each side of it, become of equal length. This is the shape of the foot of a bird, though birds still retain five joints in their fourth toe, although they gain no advantage by so doing. These five phalanges are inexplicable if the bird was created as it stands, but they are easily understood if the bird was evolved from a reptile.
Any animal that uses its hind legs entirely for running or for such simple movements as scratching, that has its feet near the middle line of the body, and that runs fast, tends to simplify the structure of its foot by fusing together bones that were originally separate. In all ordinary animals the ankle joint is made up of many small bones and is, even in ourselves, a point of weakness. In a small chick these bones are represented by cartilage, but as the bird grows up they
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