Part 3 

 GENERAL AND APPLIED BIOLOGY 



Chapter 29 



GEOGRAPHIC DISTRIBUTION OF ANIMALS 



AND PLANTS— BIOGEOGRAPHY (ZOOGEOGRAPHY 



AND PHYTOGEOGRAPHY) 



The scientific study of the distribution of living organisms in space is 

 known as hiogeography. If the study pertains to animals the science is 

 called zoogeography; if it pertains to plants it is known as phytogeog- 

 raphy. In general the study of the geographic distribution of living or- 

 ganisms deals with larger areas or regions such as a country or continent, 

 while the ecologic study of those same organisms would be made in a 

 more or less limited area, such as a field, pond, or river. Ecology is con- 

 sidered elsewhere in another chapter. 



I. WHY STUDY GEOGRAPHIC DISTRIBUTION? 



Zoogeography may profitably be studied for the following reasons : ( 1 ) 

 To see that each species of animal is rather definitely restricted to certain 

 regions of the world or to certain limited areas of a certain environment. 

 The entire world has been divided into seven major geographic regions 

 and each region has certain animals which are typical and representative 

 for that region (Fig. 310) . It is by a thorough study of geographic distri- 

 bution that the various principles of zoogeography can be properly learned 

 and interpreted. (2) To see, as a result of adaptation of a species of ani- 

 mals to a particular environment, that such a species is thus restricted 

 by its resulting morphology and physiology to those parts of the world in 

 which that particular type of environment exists. If animals change 

 because of adaptations, they must then select an environment which will 

 be satisfactory if they are to live successfully. All of this study attempts 



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