Somerset Maugham wrote "Love is only a dirty trick played on us to achieve continuation of the species."
We are the product of the quickest, meanest and the most hungry sperm. We need to know that out of millions of sperms you the reader were a product of the quickest!
Continuation of species is the dichotomy of lust and the innate ability to procreate. Evolution is a part of life, but it is human love on which our human progress is based; it is our humanitarianism to continue caring and catering to the needs of those who lose physical abilities and have passed the reproductive age and become impotent, afflicted, old and senile.
One can of course argue that orgasm plays a significant role in the multiplication of our numbers. Imagine an ejaculation sans pleasure yet, on the other hand, birth itself is extremely painful and motherhood is not about lust at all, it is something far beyond sexual desire.
What makes a female ready to have multiple pregnancies knowing well that the offspring will not even carry her family name in a male dominated society? It is motherhood and its innate infinite love: We are not just a biomass, we are born to think and innovate and create other than make love. The difference between us and animals or a bush or a tree is that we think. Human population would probably be way less than a thousand if ejaculation were not usually accompanied by an orgasm.
Desmond Morris in his book 'The Naked Ape' presented an intriguing theory about this.
'Love is not only an evolutionary by-product of the need to reproduce, but might've been vital to the survival of the species during the time when hominids left the forests to go hunting in the woodland and Savannah. Males needed to leave females behind to look after the young while they were out in the Savannah hunting.' Morris made a number of other claims like Homo Sapiens have the largest brain of all primates but also the largest penis, and is therefore "the sexiest primate" alive.
Morris wrote 'that our fleshy ear-lobes, which are unique to humans, are erogenous zones, the stimulation of which can cause orgasm in both males and females.'
Morris reasoned that 'more rounded shape of human female breasts means they are mainly a sexual signalling device rather than simply for providing milk for infants.'
Morris explained 'the intense human pair bond evolved so that men who were out hunting could trust that their mates back home were not having sex with other men, and that sparse body hair evolved because the "nakedness" helped intensify pair bonding by increasing tactile pleasure.'