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Peter Jackson, Professor of Geography, teaches at the University of Sheffield, in the UK. His research concentrates on, among other topics, social and cultural geography.
The major thrust of this article seems to be that geography is as much responsible for connections between people as heritage (roots), and that geography, along with cultural studies, searches for the connections "which have brought different cultural influences together in particular places..."
My understanding is that people often try to define themselves primarily by where their ancestors have come (roots), while Jackson for the pathways (routes) that bring people together. He asserts that people are never simply one thing: a race or a career or a nationality, etc. These may be points from which we begin our search into the essence of who a person is, but there is so much more than these few clarifiers.
This idea falls under the purview of "human" geography, and is closely tied to cultural studies. Cultural geography takes a more holistic view of people: that people exist on a level separate from the "sum of their parts." Culture is becoming more reflective of "whole ways of life," and refers to all people, rather than a portion that may only represent a specific, "elite" group.
Jackson also speaks to the "politics of Empire." He states,
...the study of Empire is inevitably a study of overlapping territories and intertwined histories. Geographers are irresistibly drawn to...connect rather than to separate and many would endorse [Said's] conclusion that 'No one today is purely one thing.'
This means that Jackson looks not to the line from which we spring in terms of family history, but also to the way people are joined across the physical space of geography, exchanging ideas and cultural beliefs or practices, which also contribute to the "sum" of who we are.
Jackson describes the widespread effect of Imperialism, as well. (Wikipedia defines "Imperialism is defined as:
'...the creation and maintenance of an unequal economic, cultural and territorial relationship, usually between states and often in the form of an empire, based on domination and subordination.')
Jackson purports that Imperialism was responsible for "mixing cultures and identities on a global scale." (This would speak directly to the "colonization" by the British Empire, in places like India, China, etc.) He goes on to explain that there is a paradox here: Imperialism led people to lean toward more segregated identities: being only "white, black, or Western, or Oriental." People cling to traditions, homelands, languages, etc., as if this was the sole make-up of an individual, and the most important aspects of the human experience.
Whereas people often feel the need to isolate themselves into groups to retain a certain identity, Jackson's article states:
'Survival in fact is about the connection between things.'
I would expect Jackson would agree that "no man is an island," and neither should he want to be.