Wikipedia
Hypermorphosis is a biological phenomenon related to the development time and rate of an organism. Hypermorphosis is a heterochronic process, i.e. a change in the timing or rate of development in an organism. In hypermorphosis, the rate of development of an organism is not altered, but the time of offset of the change in question is extended. For example, it is common knowledge that major physical changes in the human body are completed by the time someone is 18 years of age. In cases of hypermorphosis, however, the changes continue to take place after the normal time frame. Hypermorphosis may serve to explain evolution in certain cases. For instance, the occurrence of this phenomenon with respect to cognitive functions in apes may have resulted in a gradual increase in intelligence, the end result being intelligent human beings.