s the low, retreating forehead and the prominent
eyebrow ridges.]

[Illustration: SUGGESTED GENEALOGICAL TREE OF MAN AND ANTHROPOID APES

From Sir Arthur Keith; the lettering to the right has been slightly
simplified.]

We are on firmer, though still uncertain, ground when we state the
probability that it was in Asia that the precursors of man were
separated off from monkeys and apes, and began to be terrestrial rather
than arboreal. Professor Lull points out that Asia is nearest to the
oldest known human remains (in Java), and that Asia was the seat of the
most ancient civilisations and the original home of many domesticated
animals and cultivated plants. The probability is that the cradle of the
human race was in Asia.

Man's Arboreal Apprenticeship

At this point it will be useful to consider man's arboreal
apprenticeship and how he became a terrestrial journeyman. Professor
Wood Jones has worked out very convincingly the thesis that man had no
direct four-footed ancestry, but that the Primate stock to which he
belongs was from its first divergence arboreal. He maintains that the
leading peculiarities of the immediate precursors of man were wrought
out during a long arboreal apprenticeship. The first great gain of
arboreal life on bipedal erect lines (not after the quadrupedal fashion
of tree-sloths, for instance) was the emancipation of the hand. The
foot became the supporting and branch-gripping member, and the hand was
set free to reach upward, to hang on by, to seize the fruit, to lift it
and hold it to the mouth, and to hug the young one close to the breast.
The hand thus set free has remained plastic--a generalised, not a
specialised member. Much has followed from man's "handiness."

The arboreal life had many other consequences. It led to an increased
freedom of movement of the thigh on the hip joint, to muscular
arrangements for balancing the body on the leg, to making the backbone a
supple yet stable curved pillar, to a strongly developed collar-bone
which is only found well-formed when the fore-limb is used for more than
support, and to a power of "opposing" the thumb and the big toe to the
other digits of the hand and foot--an obvious advantage for
branch-gripping. But the evolution of a free hand made it possible to
dispense with protrusive lips and gripping teeth. Thus began the
recession of the snout region, the associated enlargement of the
brain-box, and the bringing of the eyes to the front.