Kohanim Genetic Testing

Why should this be the case?  We do know that genetic testing has demonstrated that Jews are more similar genetically to other Jews widely separated in space, than they are with non-Jews in their host countries.  We also know that there are genetic markers on the Y-chromosome (carried exclusively by males) that appear to be almost unique to men who identify themselves as Kohanim .  Since our traits and proclivities are at least partially determined by our DNA, it appears that there is a physiological basis for the different tribes’ assumption of different roles within the larger community of Israel.  And clearly, the community as a whole is strengthened when each of its members plays to his or her specific strengths.  This would apply to tribal roles, gender roles, etc.  In Hebrew the part each of us is given to play is called our tafkid and King reflects the duality inherent in the human condition.  We are a soul, infinite and eternal, but we inhabit a mortal body.  The body allows the soul to interact with and elevate the physical world, but when the soul stops directing the activity of the body, and instead becomes, as it were, fused with and under the control of the body and its ephemeral desires, then it gets dragged down into the mud of earth-bound materiality.  Rather than the spirit raising up the material, the material drags the spirit down.  The result, in order for the spirit to be free, is necessarily death.  In fact, the commentators raise the possibility that it is this necessity for death to free the soul from its material prison, that is the reason for the fact that Torah legislates contamination for anyone who comes into contact with a human corpse.