As early as 7000 BCE, during the Neolithic Age, people of Jericho refashioned .

plastered skulls

Explanation:

The people of Jericho refashioned plastered skulls. Plastered skulls were made in the ancient Levant. They are the oldest form of art in the Middle East. These skulls show the earliest forms of burial practices.

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artists need to create a realistic interpretation so that people in general can relate to the artwork. for a common people, an artist's impression gets increased only if he can create something which would look realistic. an abstract is difficult for a common people to understand whereas if a person can draw a girl with simple pencil sketch and if that looks like a real figure then the latter will be praised more than the former.