The Oxford dictionary defines the word unnatural as a sort of deviation from what would be the standard path of any given element in terms of physical attributes. Looking at the scenario through a perspective of social standards, for a white woman to wed a black man and vice-versa would be an act against nature. To deviate from what is usually expected, as it would be for Desdemona our melanin lacking object of Othello the pigmented man's affection. But we see that the standard of what is natural, is once again, rooted in social norms birthed by political and economic forces. Barbantio is feeling the throes of uncertainty burrowing into his well layed plans for his fortune and estate. As it is usual for people to fear that which is alien to their immediate sense experience, Barbantio feels it is appropriate to consider his daughters coupling with a moor unnatural, as it may very well send his wealth into foreign places. This way he may find some sort of solace in his illogical ways of thinking. Placed in a similar situation I would find no resistance from my family members. In today's world, I would consider mixed racial relationships to be just as taboo as in the olden days if not more so, and I base this loosely on the fact that I consider racism to be at an all time high. And growing up surrounded with strong convictions against marrying white. These convictions were not displayed at home by my immediate family but were evident in my social settings, school, neighborhood etc.