How was inheritance before Islam, who were the heirs, and how was inheritance distributed among each heir, with supporting evidence for that?

The reason for the revelation of the noble verse: (For men is a share of what the parents and close relatives leave, and for women is a share of what the parents and close relatives leave, be it little or much—a legal share) is that in the pre-Islamic era (Jahiliyyah), people would prevent women and minors from inheriting, restricting inheritance to adult men. Islam then came to establish the laws of inheritance with equity and justice, determining the share of each heir.