PROBLEM 5. The Stages of Mail's Develop?7tent on the Earth 



565 



Old Stone Age 

 Paleolithic 



New Stone Age 

 Neolithic 



Fig. 513 Compare these Old Stone Age and New Stone Age artifacts. 



bones of other animals in the cave, indi- 

 cating what probably was used as food. 

 If charcoal or charred bones are present 

 we may assume that these men knew the 

 use of fire. All this gives us an idea of 

 their culture. By the word culture, ap- 

 plied to a group of men, we mean how 

 they live, what they do, and what they 

 think. Studying the cultures of early 

 men is as interesting and as important as 

 the study of their bones. Do Exercise i. 

 The date of man's beginnings. You 

 learned earlier that the age of fossils can 

 be roughly calculated from the kinds of 

 rock deposits in which they are found. 

 The presence of other fossils that have 

 already been given a date helps, too. But 

 setting the time of the appearance of 

 manlike forms on the earth presents diffi- 

 culties. For one thing- the fossils of these 

 early forms are sometimes found in sand 

 or gravel, not in rock. For this and other 

 reasons experts have not agreed on the 

 exact date. Most believe that manlike 



animals appeared at least a million years 

 ago; some think it was somewhat earlier 

 or later, perhaps two million, perhaps 

 half a million years ago. In this book we 

 shall assume that manlike forms ap- 

 peared about a million years ago. But 

 Homo sapiens appeared much more re- 

 cently. It is usually believed that the 

 first sure fossils of Homo sapiens, our 

 own species, date from about 25,000 

 years ago. 



Twenty-five thousand years seems a 

 long time, but considering the age of 

 the earth it is a very short time. To help 

 you realize this and to help you keep 

 track of man through the ages, suppose 

 we let the twelve hours of the clock 

 represent a million years. By studying 

 Figure 514 you can see that, if the first 

 manlike organisms appear at 12 o'clock 

 noon, the hour hand must move well on 

 toward midnight before we can show 

 the appearance of Homo sapiens. On this 

 clock his appearance would be shown 



