The source you cited is a good source, but you likely do not understand it and grossly misrepresent it, go figure.
https://hms.harvard.edu/news/origins-mutation
The research identified new mutation-fueling mechanisms and some that were already known. One mechanism was related to inaccurate copying of DNA, another was related to chemical damage occurring to the DNA.
The analysis also pinpointed a machinery involved in human gene regulation as a frequent culprit in mutations. This machinery is particularly active during early embryonic development, and most of the mutations introduced by the machinery occur during this period.
In one surprising finding, the researchers identified a mutation-driving mechanism that was not related to DNA copying and cellular division—processes that are prone to mutation-causing glitches. This previously unsuspected mechanism leads to mutations in egg cells stored in the ovaries.
Relevance and implications
The researchers are now working to incorporate some of the results in a model of human-mutation rate along the genome in an effort to help predict the chance that a specific mutation would occur at a specific location in the genome. The goal is to help in the analysis of disease mutations and in discovery of genes causing rare diseases. The model may also serve to highlight genes of key importance to human health and survival.
The work was supported by the National Institutes of Health (R35GM127131, R01MH101244, U01HG009088, and R01 HG010372) and National Heart Lung Blood Institute (R01HL131768).