Probably, in all kinds of human features, there isn't a feature more influential and impact than reproduction by a pair of humans to human's life, politics, culture, arts, emotions and religions. If there is no difference in between the male and female genders and the production of young bodies by sexual intercourse, then human. life will lose its majority of charm.
Double-life genetic reproduction is done via mating between male and female. Life is divided into two bodies, the male has a strong build, the female has tenderness, both are combined together as a group(family), and feed the young ones. Then there appears the love between men and women, love between parents and children, and love between brothers. The spiritual source will be, continuously flowing out, while the humanities, morals, laws, politics and arts are being created naturally.
Why doesn't reproduction of life opt for single or three-body form?
Imaging that heredity of life is from reproduction of a single cell, then you will find that human life will lose its existing charms and attractions, and all the feelings and arts based on love and family will be all gone.
Three-body form reproduction, i.e. heredity must be done by intercourse between male, middle body and female, then the cultures, arts, morals, social forms, even the political forms of human beings will be totally turned into another appearance. The us, reproduced by mating of male and female simply cannot be imaging what that society would be.
What intelligence has made heredity life prefer the two-body reproduction? Is it the unknown motivation in genes, or the advanced intelligence beyond genes? This gleam of light passed from eternity is strong enough to make us feel that the super intelligent powers from that light source are great and unreachable.