The Origins of Music: Preface - Preface

To make a somewhat different point,I boxed the points giving data

on the smallest known primate,the mouse lemur (Microcebus murinus),

and a medium-size insectivore,the desert hedgehog (Hemiechinus

auritus).Mammalian species do differ significantly in the sizes of their

brains relative to body size,a difference in “encephalization”that I ana-

lyzed in great detail (Jerison 1991).Primates are the most encephalized

order of living mammals and insectivores the least.I chose my specimens

to show that the brain hangs together in more or less the same way,

regardless of the evolutionary and genetic forces that resulted in its

present size.In other words,whether a brain evolved to larger size

because of selection for more information-processing capacity

(encephalization) or because of the evolution of a larger body (allomet-

ric effect),its parts maintain approximately constant relationships with

184 Harry Jerison

Figure 12.2

Volume of cerebellum and basal ganglia as a function of brain size in seventy-six species

of mammals.Squares identify data points for the mouse lemur (Microcebus murinus) and

desert hedgehog (Hemiechinus auritus);a few other species in the sample are also identi-

fied.(Data from Stephan,Frahm,and Baron 1981.)

Fig.12.2