Why were mother goddesses especially important to early civilizations?

From what I understand, the earliest dominant gods were female because, at that point in human development, they believed that life sprang from women spontaneously, without the influence of males. They also noted the correlation between the menstrual cycle and the lunar cycle. All these things were beyond their understanding........and what better to do with things you don't understand than ascribe them to deity! They later found that life needed male influence to form and thus the paradigm shift.