382 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1958 
What we have tried to say thus far is that man has enjoyed the ad- 
vantage of an earth that was, so to speak, a long time getting ready 
for him. More specifically put, he has evolved in relation to and by 
virtue of a highly organized and specialized environment. The earth 
is fit for him and he for it not only because of what he found here 
but of what went on here during the millions of years before his ad- 
vent. Surely it behooves him to think twice before causing too much 
disruption. 
Now let us look at man himself more closely. He is often called a 
Pleistocene mammal, which means that he appeared during the great 
glacial period in geological history. This was a time of storm and 
stress. Evaporation lowered the oceans to feed the growing polar 
and alpine ice. As the ice expanded it narrowed the biosphere into 
an equatorial girdle and within that girdle rainfall was probably 
heavy, favoring forests. At times the ice retreated, as it is doing now. 
Moisture lessened, temperatures rose, the living girdle widened to- 
ward the poles, and places which had been humid forest became 
desert. Such have been conditions during the past million years or so, 
the time that human beings have existed. 
We are a novelty, if we do say so. Reach up to chin yourself, note 
the articulation of your shoulder joint and the ability of your hands 
to grasp a bar (or branch) strong enough to sustain your weight. 
Then ask yourself “What kind of a community—desert, grassland, or 
forest—did early men, my own ancestors, probably come from?” It 
seems clear that at first man, like other species, was restricted in range 
and habitat by certain limiting factors, temperature and suitable food 
being among them. 
But not for long. Why? Look again at your hands. Note the 
opposing thumb and fingers and compare their manipulative range 
with that of any bird or beast you know. Think of your erect spine 
that frees your forelimbs from serving as legs, your head pivoted 
for swinging about the horizon, and your eyes set to form between 
them the base of a triangle. Any object you look at becomes the 
apex of that triangle enabling you unconsciously to form some judg- 
ment of its size or distance, or both. With such equipment an 
astonishing range of experience becomes possible. 
That is not all. You have a central nervous system that is large to 
begin with and can continue its growth. Any experience, we know, 
registers in this central nervous system, to be recalled or reconsidered 
in future. Over and above what is called the “old brain” in mammals, 
you possess a powerfully developed “new brain,” the busy nerve 
center of conscious activity. The “old brain” for its part attends to 
many routine matters without bothering headquarters. 
Finally, human beings are equipped with a remarkably versatile 
vocal system, capable of producing an infinite variety of sound com- 
