Speaking without the expertise of a theologian or medical doctor, there are to my mind only two reasonably clear natural divisions in prenatal life: its beginning, at conception, and its end, at birth. (firstthings.com)
Some analysts have suggested that Carolyn McCarthy's seat, the Fourth District in Nassau County, might be carved up instead, but that is a less natural division, since Long Island's suburban population has grown enough to still warrant four full districts. (fivethirtyeight.blogs.nytimes.com)
This kind of pattern can be obtained either through natural divisions with heterogeneous demographics (eg. (politics.stackexchange.com)