...universal love and the welfare of the species as a whole are concepts that simply do not make evolutionary sense.

A drive to procreate

Cicero, On Duties, Book I, p.23

For since it is by nature common to all animals that they have a drive to procreate, the first fellowship exists within marriage itself, and the next with one's children.

Promises should not be kept if they are disadvantageous to those to whom you have made them

Cicero, On Duties, Book I, p.13.

Nor, if they harm you more than they benefit the person who you have promised, is it contrary to good to prefer the greater good to the lesser. For example, if you had made an appointment to appear for someone as advocate in the near future, and in the meantime your son had fallen seriously ill, it would not be contrary to your duty not to do as you had said. Rather, the person to whom you had made the promise would be failing in his duty if he complained that he had been abandoned. Again, who does not see that if someone is forced to make a promise through fear, or deceived into it by trickery, the promise ought not stand?

Cicero is suggesting that the unethical behavior of others may relieve us of the obligation to fulfill out commitments. Where does this sort of reasoning end?

Epictetus on children and marriage

Foucault, The Care of the Self, p. 155:

[Epictetus] refers to the social obligations that no man must shirk and of which marriage forms a part, alongside the duties that pertain to political life, religion, and the family: 'citizenship, marriage, procreation of children, worship of God, care of parents.'

But not really. On page 156 Foucault says "it was the same with marriage as with all the other practices that the Stoics classed among the proegoumena, the things that are preferable. There may be circumstances in which it is not obligatory."

Musonius stakes out the pro-marriage, pro-kids position

Hence, it is clear that it is appropriate for the philosopher to devote attention to marriage and the production of children.

Musonius points to the gods - they got married - and to nature - clearly the gods intended man to marry and procreate, and if that's what is intended for man then that is what is intended for the philosophers that walk among man.

Also, note that Epictetus had strong feelings about the sanctity of marriage vows (though he suggested philosophers should not marry), made clear in his reprimands to the wayward senator.