FIG. 408.--ARTIFICIAL SELECTION. Its effects in causing varieties in one species. Which of the dogs is specialized for speed? Driving cattle? Stopping cattle? Trailing by scent? Finding game? Drawing vehicles? Going into holes? House pet? Cold weather? In Mexico there is a hairless dog specialized for hot climates. The widely differing environments under various forms of domestication cause “sports” which breeders are quick to take advantage of when wishing to develop new varieties. Professor De Vries by cultivating American evening primroses in Europe has shown that a sudden change of environment may cause not only varieties but new species to arise.] HUMAN BIOLOGY CHAPTER I INTRODUCTION To which _branch_ of animals does man belong? To which _class_ and _order_ in that branch? (Animal Biology, pages 125, 193.) There is no other animal _species in the same genus or order_ with man. This shows a wide _physical_ difference between man and other animals, but man’s _mind_ isolates him among the other animals still more. [Illustration: FIG. 1.--FACIAL ANGLES of Caucasian (nearly 90°) and Ethiopian (about 70°). The angle between lines crossing at front of upper jaw near base of nose, one line drawn from most prominent part of forehead, the other through hole of ear.] The human species is divided into =five varieties= or races: 1. _Caucasian_ (Fig. 1). Skin fair, hair wavy, eyes oval. (Europe except Finns and Lapps, Western Asia, America.) 2. _Mongolian._ Skin yellow, hair straight and black, face flat, nose blunt, almond eyes. (Central Asia, China, Japan, Lapps and Finns of Europe, Eskimos of North America.) 3. _Americans._ Skin copper red, hair straight, nose straight or arched. (North and South America.) 4. _Malay._ Skin brown, face flat, hair black. (Australia and Islands of Pacific.) 5. _Ethiopian_ (Fig. 1). Skin dark, hair woolly, nose broad, lips thick, jaws and teeth prominent, forehead retreating, great toe shorter than next toe and separate. (Africa, America.) There is a _struggle between the races_ for the possession of different lands. The Caucasian is gaining in Australia, Africa, and America. With difficulty the Mongolians are kept from the western shores of America. The Ethiopian in America shows a lessened rate of increase every decade; this may be due to the tendency of the race to crowd into cities and the strain of suddenly changing from jungle life in less than two centuries. _Civilization is a strain_ upon any race. It is destroying the American Indian. The Mongolian and Caucasian survive civilization best, but insanity is increasing rapidly among the latter. [Illustration: FIG. 2.--INDIAN WEAPONS: LANCE AND ARROW HEADS. From a bank of mussel shells (remains of savage feast) at Keyport, N.J.]