As the Predynastic period progressed, the handles on pottery evolved from functional to ornamental. The degree to which any given archaeological site has functional or ornamental pottery can also be used to determine the relative date of the site. Since there is little difference between Tasian ceramics and Badarian pottery, the Tasian Culture overlaps the Badarian range significantly.[48] From the Tasian period onward, it appears that Upper Egypt was influenced strongly by the culture of Lower Egypt.[49]