ABSTRACT
GENETIC DIFFERENCE S i n man , lik e thos e betwee n individual s o f an y anima l or plan t specie s and thos e betwee n species , ar e al l products o f th e evolu -' tionar y developmen t o f th e livin g world . Thes e differences , w i t h thei r behavioral consequences , ca n onl y b e understoo d i n th e ligh t o f evolution , sub
specie evolutionis. Ou r understandin g o f evolution , however , i s itsel f evolving .
The Darwin-Wallac e theor y o f evolutio n appeare d mor e tha n a centur y ago .
The developmen t o f th e evolutionar y though t ha s gon e throug h severa l stages .
I t wa s necessary , first o f all , to demonstrat e beyon d reasonabl e doub t tha t evo -
lution had , i n fact , take n place . Roughl y th e first fou r decade s afte r Darwin ,
unti l abou t 1900 , wer e dominate d b y studie s i n comparativ e anatomy , embryol -
ogy, systematics , zoogeography , phytogeography , an d paleontology , designe d t o
discover an d examin e th e evidence s o f evolution . Durin g th e sam e period , th e
first sketch y attempt s wer e mad e t o trac e th e path s tha t th e evolutio n o f th e
living wor l d actuall y followed . Th e evidence s o f evolutio n ar e no w s o wel l
known tha t the y ar e par t o f th e basi c colleg e an d eve n hig h schoo l course s o f
biology. O n th e contrary , th e phylogenie s o f th e anima l an d plan t kingdoms ,
and particularl y th e phylogen y o f man , ar e fa r fro m completel y known , an d
they ar e activel y studie d today .
