Comparison of Dominance and Overdominace Theories of Heterosis

Similarities

Effect of inbreeding

Inbreeding tends to decline in vigour

Also leads to decline in vigour

Out breeding

Out breeding restores vigour

Out breeding restores vigour

Parental diversity

Heterosis is associated with parental diversity.

Also associated with parental diversity

Control

Heterosis is controlled by genes

Also controlled by genes.

Difference

Causes of heterosis

Heterosis results due to masking effect of dominant desirable allele or over harmful recessive alleles. 

Heterosis results due to complementation between divergent alleles.