Origin of Mutations 



so excessive as to be positively injurious ; then 

 natural selection will step in and eliminate the 

 species. But before this happens, something 

 may cause a rearrangement of the biological 

 molecules in the fertilised egg, and thus a muta- 

 tion may arise, which, so to speak, strikes out a 

 new line. 



Finally, on this conception there may be some 

 sort of connection between fluctuating variations 

 and mutations. We can picture the fluctuating 

 variations being piled up, one upon the other, 

 until there results a rearrangement of the atoms 

 in one or more of the biological molecules which, 

 in turn, causes a mutation. 



Occasionally this remodelling, as it were, of 

 one biological molecule may affect certain of the 

 other molecules, and thus lead to correlated 

 mutations. 



ib 9 



