[4] In 1963, he was awarded a PhD from the Geography Department at University of California, Berkeley, upon defending his dissertation entitled "Plants, animals, and man in the Outer Leeward Islands, West Indies.
[4] Harris has conducted research investigations in many parts of the world, including New Guinea, the Torres Strait, Africa, Central America and Eurasia.
His research has generally been concerned with the ecology and development of agriculture and other modes of subsistence among human cultures.
[1] In 1989 Harris and a colleague were invited to lead the archaeological investigations of the environment at the central Asian Early Neolithic site of Jeitun, located in what is now Turkmenistan.
Continuing investigations during the 1990s by Harris and the international project team at Jeitun and surrounds obtained conclusive evidence of agricultural-pastoral settlement by at least 6000 BCE, the earliest indications of agricultural practices in Central Asia known at that point.