Uralic *koje 'man, person' is a remnant of a Borean word which spread as a Wanderwort into East Caucasian *χχHweje (NCED 26) and Tibeto-Burman *qhʷi:j 'dog'1. The suffixed variant *koj(e)-ra > Uralic *kojra 'male (dog, man)' would correspond to East Caucasian *χχHwej-rV 'dog' (oblique stem) and Kartvelian (Svan) xwir- 'male (dog)'. IE *wi:r-o- 'man, husband'2 would also belong here, although probably as an inherited word.
On the other hand, Sinitic *khʷi:-n 'dog' borrowed into IE *k´(u)wo:n (a cultural loanword whose direction has been often reversed by Indo-Europeanists3) would be derived from the same lexem with a different suffix.
Unfortunately, most macro-comparativists are unable to differentiate between borrowed and inherited lexicon4, as they blindly apply the comparative method coined in the 19th by Neogrammarians, which assumes common inheritance from a single source, represented by the genealogical tree model. By applying it to some hundreds of words, this process ultimately leads to the reconstruction of non-existent macro-families whose chronology is shallower (typically 2-3 times) than the actual ones.
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1 For which Starostin reconstructed a Sino-Caucasian etymology.
2 For which Starostin reconstructed an Eurasiatic (Nostratic) etymology.
3 T.V. Gamkrelidze & V.V. Ivanov (1995): Indo-European and the Indo-Europeans, p. 507.
4 Generally, the lesser the semantic latitude,
the likelier we're dealing with a Wanderwort, as it's often the case
with names of domesticated animals.
