INDIVIDUALS, CELLS AND POPULATIONS 



Equipped with this knowledge of individuals we can return to 

 consider their parts, to find out what happens within each individual. 

 We can try to discover what the rest of the cell, the cytoplasm, has 

 to do with the nucleus in determining heredity, and how it reacts 

 with the nucleus to produce the differentiation of cells and tissues 

 during development. 



And finally we can see the individual as part of something larger. 

 We can recognise its heredity as part of a system of individuals, 

 a population breeding together, descended from a long line of 

 ancestors similarly related, and likely also to give rise to a long line 

 of descendants. From the most minute and transient events we shall 

 come to envisage the vast and enduring laws of change which we 

 associate with the name of evolution. 



It is thus in three parts, in relation to individuals, to cells and to 

 populations, that we shall have to unfold the working of genetics. 



REFERENCES 



AKERMAN, A. 1922. Untersuchungcn fiber cine in direkten SonneiJichte nicht 



lebensfahige Sippe von Avena sativa. Hereditas, 3 : i^rj-i']']. 

 BOVERi, T. 1889. Ein geschlechtlich erzeugter Organismus ohne miitteriiche 



Eigenschaften. Sitz. Ber. Ges.Morph. Phys. Miincheti, 5. (Translation by T. H. 



Morgan, 1893. Am. Nat. 27: 222-232.) 

 HALDANE, J. B. s. 1946. The interaction of nature and nurture. Atin. Eugenics, 13: 



197-205. 

 HAMMERLiNG, J. 1943 . Ein- und zweikemige Transplantc zwischen Acetahularia 



mediterranea und A. crenulata. Z.I.A.V., 8i: 1 14-180. 

 JOHANNSEN, w. 1911. The genotype concept of heredity. Aw. Nat., 45: 129-159. 



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