12 



SOCIAL EVOLUTION 



This increased experimentation and interest led to the 

 discovery of a buried paper written in 18G5 by Gregor 

 Mendel, an Austro-Silesian abbot. It proved to be a dis- 

 closure of great importance. Mendel had experimented 

 in his garden upon the common edible pea. The law of 



Parental generation giant D variety dwarf R variety 



First filial (hybrid) 

 generation F, 



all offspring D(R) self-fertilized 

 are giants they yield 



D D D(R) R R 



giants 25% giants 50 % giants (impure) 25% dwarfs dwarfs 

 (pure) (pure) (pure) (pure) 



FIGURE 4. Diagram of Mendelian Inheritance in the Pea, where D stands 

 for the Dominant Character, D(R) for the Impure Dominant, and R 

 for the Recessive Character. 



heredity which he discovered was ridiculed at the time 

 of the writing of his paper and the discovery was to 

 all intents and purposes lost to science until about 

 1900. 



The remarkable results of Mendel's experiments upon 

 the common pea were as follows. He found that when 

 he crossed a giant variety of 6 to 7 feet with a dwarf 

 variety, % to l 1 /^ feet high, the offspring were all tall. 

 The character of tallness which appeared in the hybrid 

 generation (Fj), to the exclusion of dwarfness, was called 

 by Mendel the "dominant" character, the other was 



