About 150,000 years ago there appeared in Europe races of mankind that left more relics of their civilization.[6] These were the Neanderthaloid races. There is no evidence of the connection of these races with the Java man or the Heidelberg man. Here, as elsewhere in the evolution of races and species, nature does not work in a straight line of descent, but by differentiation and variation.
In 1856 the first discovery of a specimen of the Neanderthal man was found at the entrance of a small ravine on the right bank of the River Dussel, in Rhenish Prussia. This was the first discovery of the Paleolithic man to cause serious reflection on the possibility of a prehistoric race in Europe. Its age is estimated at 50,000 years. This was followed by other discoveries of the Mid-Pleistocene period, until there were a number of discoveries of similar specimens of the Neanderthal race, varying in some respects from each other. The first had a brain capacity of 1230 c.c., while that of the average European is about 1500 c.c. Some of the specimens showed a skull capacity larger than the first specimen, but the average is lower than that of any living race, unless it be that of the Australians.
Later were discovered human remains of a somewhat higher type, known as the Aurignacian, of the Crô-Magnon race. These are probably ancestors of the living races of Europe existing 25,000 to 50,000 years ago. They represent the first races to which may be accorded definite relationship with the recent races.
Thus we have evidences of the great antiquity of man and a series of remains showing continual advancement over a period of nearly 500,000 years--the Pithecanthropus, Heidelberg, Piltdown, and Neanderthal, though expressing gradations of development in the order named, appear to be unrelated in their origin and descent, and are classed as separate species long since extinct. The Crô-Magnon people seem more directly related to modern man. Perhaps in the Neolithic Age they may have been the forebears of present races, either through direct or indirect lines.
_The Unity of the Human Race_.--Though there are evidences, as shown above, that there were many branches of the human race, or species, some of which became extinct without leaving any records of the passing on of their cultures to others, there is a pretty generally concerted opinion that all branches of the human race are related and have sprung from the same ancestors. There have been differences of opinion regarding this view, some holding that there are several centres of development in which the precursor of man assumed a human form (polygenesis), and others holding that according to the law of differentiation and zoological development there must have been at some time one origin of the species (monogenesis). So far as the scientific investigation of mankind is concerned, it is rather immaterial which theory is accepted. We know that multitudes of tribes and races differ in minor parts of structure, differ in mental capacity, and hence in qualities of civilization, and yet in general form, brain structure, and mental processes, it is the same human being wherever found. So we may assume that there is a unity of the race.