Karyotypes can be used for many purposes ; such as to study chromosomal aberrations , cellular function , taxonomic relationships , and to gather information about past evolutionary events .
Karyotypes may be studied to gather information about past evolutionary events , such as polyploidy .
In his book , Köhler describes how the apes use their hands : `` large , powerful and flexible hands are natural links between himself and the world of things , and he attains the necessary amount of muscular force and co-ordination at an earlier age than the human child '' Köhler ( 1925 ) .