“The genes hold culture on a leash. The leash is very long, but inevitably values will be constrained in accordance with their effects on the human gene pool. The brain is a product of evolution” (Wilson 167).
As Wilson claims we are bound by our genetics, such human characteristics of love can be simplified as a means for reproduction involving a purely physical as well as a compansionate aspect. Sexual attraction is one motivator in mate selection and this is traditionally been thought to been based off of physical attractiveness and whether a person looks sickly or not, will be able to bear children, and some research even shows that it is based off of scent - - directly reflecting genetics. Because the Oankali don’t need to rely on guessing if a person would be a good genetic match from attractiveness, there doesn’t need to be an element of physicality to sexual reproduction. Lilith’s utter repulsion by the appearance of the aliens repulsed her so much that she “deliberately dug her nails into her palm until they all but broke the skin […] to distract her (Butler 15) and it took her months to get used to their appearances. After she was used to the appearance of the Oankali and the oolioo and awakened other humans perhaps a shift in choosing a mate based on physical attraction was apparent. Liltih surprised her captors when she did not chose a large strong attractive mate but instead chose a shorter older man. While their relationship proceeded in a somewhat traditional fashion, the addition of the oolioo complicated the physical aspect of the relationship and this can perhaps be explain by Wilson as being because the ability to reproduce with just a man and a woman was lost. After losing the ability to conceive without the the oolio, Lilith and Joseph, although still caring for each other are repulsed by the idea of the other as sexual beings without the ooloi. When Lilth tries to hold Joseph’s hand they force themselves to remain holding hands but “shudder with revulsion”(Butler 220). Yet on the other hand earlier that day she was missing Nikanj and that fact that it wouldn’t be there at night for “gentle multiple touches of sensory tentacles and sensory hands”(Butler 213). This explicitly sexual language is a stark contrast to not only the way she felt initially about the alien species but also to how she currently feels about her human mate Joseph and this switch can be explained by change in the process of reproduction.
Another element of attraction, companionship or love, is women want men who will stick around through their pregnancy and through the life of the child and provide for them and men want women to be good mothers to their offspring. It is this mutual caring and ability to get along that bring Joseph and Lilith together initially. Interestingly, this aspect of the importance of caring for offspring and thus forming a loving unit is as essential for reproduction in humans as it is for the Oankali population. Although they can control their traits, they still have to rear their children and take great care. Not only that but they must also care for the oolioo. Lilith took on this role with Nikanj when she first met it and from then on her relationship with it was one that involved much more mutual dependency and caring than her relationship with Joseph. At the end of the battle between the humans and the oolioo, Lilith actually “strip[s] naked on the battlefield to lie down with the enemy”(Butler 232) and lies with Nikanj until he is able to use her body to heal himself. This type of compassionate intimacy does not in any way exist in human society other than perhaps when a person donates a kidney. In this way Lilith’s relation with her oolioo deepens as they literally become one for a time. Again, a Wilsonian explanation for this is that the compassion comes from the fact that the two can produce offspring together and need to care for one another to effectively raise and pass on the genes (however altered).
In summary, Lilith is the first being in history to go beyond to constraints of traditional evolution by being able to reproduce with a new species that do not rely on random events. As a result, the love and feeling of closeness changes from being towards her own species to a being that she can reproduce with. It also changes from being more based on physical appearance and initially attracting to being based on mutual compassion.