Spontaneous mutagenesis as a possible causal factor for the origin of obligate embryonic diapause in mammals (a hypothesis)

Abstract

The phenomenon of obligate embryonic diapause (delayed implantation) in mammals was discovered more than 150 years ago. Nevertheless, there is still no clear idea as to its origin and biological significance. Based on available data from cytogenetics, embryology, evolutionary morphology, and evolutionary ecology, it is supposed that obligatory embryonic diapause might occur in single individuals within different taxonomic groups due to chromosome mutation caused by environmental changes that affected expression of genes controlling the timing of embryogenesis.