What Is the Basis of Classification? 



Many Bases We could classify living things, as we classify stamps and 

 ships, in many different ways. One of the oldest and commonest methods 

 of sorting animals is according to the way they concern us. There are ]ood 

 animals, ]ur animals, nuisances. Or we might classify animals according to 

 the regions or the conditions in which they live — arctic animals and tropical 

 animals; mountain animals and lowland animals; land animals, air animals 

 and water animals. 



Each basis of sorting may be useful. But the first plan suggested would 

 bring together sheep, chickens and salmon; or sheep, foxes and buffaloes. 

 It would bring together mosquitoes, rats, foxes and shipworms. The second 

 plan also has its uses, but it brings together birds, bugs and bats, which all 

 fly; or whales, fish and oysters, which live in water; or spiders, elephants 

 and penguins. 



A good classification has a place for each "kind" and it avoids counting 

 any particular "kind" more than once. A land-water classification would 

 have to place the frog in one group as a tadpole and in the other group as 

 an adult. If we had a useful-harmful classification, the farmer and the fur- 

 rier could not agree about the fox. 



Choosing a Basis for Classification In classifying living things today, 

 we consider not merely their appearance or their uses to us, but all that is 

 known about them. Separating all organisms into plants and animals is 

 very old and appeals to common sense. We recognize that in a general way 

 animals are more active than plants, and more sensitive to changes in the 



This Swedish botanist and explorer de- 

 veloped a system for classifying plants 

 and animals which served to bring or- 

 der out of great confusion. Linnaeus 

 believed that every species was sep- 

 arately created, but saw similarities 

 among species which he placed in the 

 same genus. He grouped genera into 

 orders and orders into classes. He also 

 devised the binomial, or two-name, 

 method of naming species in use today 

 and made a place in his system for ev- 

 ery known plant and animal, including 

 man. His work stimulated the search 

 for new species, and laid the founda- 

 tion for the comparative study of living 

 things 



CARL LINNAEUS (1707-1778) 

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