Homo habilis

Homo erectus

Australopithecus

Dryopithecus

descent with modification

inheritance of acquired characters

variations produced in germplasm

sudden and inheritable changes

Darwin's finches

Mule

Australian Marsupials

Cichlid fishes

i $\rightarrow$ iii $\rightarrow$ iv $\rightarrow$ ii

iv $\rightarrow$ i $\rightarrow$ iii $\rightarrow$ ii

ii $\rightarrow$ iii $\rightarrow$ i $\rightarrow$ iv

ii $\rightarrow$ i $\rightarrow$ iii $\rightarrow$ iv