Answer:
The evolution of a species can be explained by observing the reproductive fitness of the organism. To increase the reproductive fitness, the organisms have adapted and evolved certain features which became imprinted on genes like the "feelings".
The falling in love can be explained by the altruism- a behavioural selfless act in which any organism increase the welfare of another organism at their own cost of survival. If this behavior enhances the reproductive success to survive then the behavior is passed on to generations and become imprinted on genes and part of behavior of organism.
Since falling in love increases the chances of survival of other species by reproducing and producing offsprings. Thus, both the evolutionary connection and evolutionary explanation is compatible.