How did merchant guilds affect medieval towns and cities?

Merchant guilds were a source of income for families who otherwise would not have any. Men could support their families by joining a merchant guild and learning a trade. If they were injured the guild would take care of the family. These men would even be paid as they were learning the craft so essentially there was room for the lower class to actually survive because of these guilds.

Because the discoveries were some of the oldest human remains.