PROBLEM D What Were the Stages of Alan's 



Development on the Earth? 



Man is one of many animals. Men fit into 

 Linnaeus' scheme of classification as do 

 all other animals. They fit into one small 

 order within the class of mammals, the 

 Primates (prime-ay 'tees). This includes 

 the animals with the most highly devel- 

 oped brains: the monkeys, the great apes, 

 and man. The order has several families; 

 one is the family Hoiimiidae (Home-in'- 

 i-dee). This family has only one genus, 

 Homo, which is the Latin word for man. 

 The genus has only one living species. 

 Homo sapiens. 



During earlier periods in the world's 

 history there lived organisms closely 

 enough related to Homo sapiens for us 

 to classify them within the genus Homo. 

 There were other forms too different to 

 place in the genus Homo but that fit 

 into the same family. All of these forms 

 are extinct (have died out). You will 

 read about some of them in this prob- 

 lem. The only species in the whole fam- 

 ily that has survived is Homo sapiens, 

 man as you and I know him. All men, 

 whether white, black, or yellow belong 

 to this species. On the surface, men may 

 look very diflrerent; actually they are so 

 much alike in internal as well as external 

 structure that they are classified as mem- 

 bers of one species. 



How we learn man's early history. How 

 can we learn about prehistoric men — 

 the men who lived before written rec- 



ords were kept? It is through fossils, of 

 course. Unfortunately, relatively few 

 fossils of early men have been found. 

 Petrifaction occurs only under special 

 conditions, and the chances of preserva- 

 tion are always small. Unless organisms 

 lived in large numbers their fossil re- 

 mains must be few and far between. 

 However, enough teeth, bones of the 

 jaw and the top of the skull, leg bones, 

 and some others have been found to give 

 us an idea of how prehistoric men of 

 various geological ages must have 

 looked. We know how tall they were, 

 how they must have held themselves and 

 walked, how large the brain must have 

 been, and in a general way what type of 

 features they must have had. The trained 

 anatomist needs only small portions of 

 a skull to tell him such things as whether 

 the head was held forward or erect, how 

 large the brain case was, and which parts 

 of the brain were well developed. 



How else can we learn about early 

 man? Sometimes we can learn much 

 about prehistoric men from the tools and 

 other articles they left behind them. All 

 such tools and implements are called 

 artifacts. Sometimes the fossil bones of 

 ancient men are discovered in a cave 

 where bones and artifacts have been kept 

 together. Because of this we can get a 

 fairly complete picture of how these 

 men must have lived. There may be 



