Beginners' zoology . Fig. 280.— Chameleon {Ano-lis), or green lizard of south-ern Far excels Europeanchameleon (Fig. 281) and allknown animals in power ofchanging colour (green, gray,yellow, bronze, and black). 148 BEGINNERS ZOOLOGY. evolution possible. The climate of the world is slowly changing,and animals must change to adapt themselves to it. A moresudden change of environment (surroundings) of animals oc-curs because of migration or isolation; these in turn are caused by the crowding ofother animals or bythe formation or dis-appearance of geo-graphical barriers,such as deserts, water
Beginners' zoology . Fig. 280.— Chameleon {Ano-lis), or green lizard of south-ern Far excels Europeanchameleon (Fig. 281) and allknown animals in power ofchanging colour (green, gray,yellow, bronze, and black). 148 BEGINNERS ZOOLOGY. evolution possible. The climate of the world is slowly changing,and animals must change to adapt themselves to it. A moresudden change of environment (surroundings) of animals oc-curs because of migration or isolation; these in turn are caused by the crowding ofother animals or bythe formation or dis-appearance of geo-graphical barriers,such as deserts, water,mountain chains. The young vary inmany ways from theirparents. Some have a more protectiveFig. OF SOUTHERN EUROPE, ^^j^^^ ^^ f^^^_ sharper claws, swifter movements, etc. The individuals poseessing such bene-ficial variations live longer and leave more offspring, and becauseof heredity transmit the desirable qualities tosome of their young. Variations which are dis-advantageous for getting food, defence, etc., causeshorter life and fewer offspring. Thus the fittestsurvive, the unfit perish; an automatic naturalselection occurs. Darwin taught that variations are infinitesimaland gradual. Recent experiments and observ
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectzoology, bookyear1921
