This article is very ethnocentric: going back to Toronto it might help, but not so much if you're headed to your ancestral village.
If your ancestors really formed a perfect binary tree, you would have billions of ancestors at a time when humans existed at most in the millions, so all humans have multiple paths of descent. In a village with constant population of a few hundred, the cross branches have to be within living memory. They don't partition neatly into generations, either.
In such places genetic your relatedness coefficient with your in-laws and your step-relations is far from zero, since your relationship is through marriage and actual blood lines. In an Indian village, your father's father's father's third wife might be your mother's sister or aunt, and their children share genes with you along both pathways -- and the language is rich with vocabulary to describe such possibilities. A friend in Bangalore told me a hobby of her mother's was to list all the possible ways to describe her kinship with her own husband.
My Kannada teacher told me about a group of women learning English, trying to figure out how to refer to your mother's older sister and your mother's younger sister: these are such different relationships to you that the single word 'aunt' could not possibly cover them both. Seniority matters as much as gene overlap! They finally decided that the words must be "maxi-mum" and "mini-mum".
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