The love of and for survival is the attaction of one living being towards other. It may be a mother who loves her children futher insuring their survival or a couple who wishes to indulge in the naughty and make a couple of kids further insuring humanity's survival as a species.
Now the later one on this subsection of the second kind of love may easily be interlinked or be confused with lust , another major driving emotion of humans. Lust and love can coexist most of the times but sometimes lust is the dominant emotion and the others, lust is. Think of them as ying and yang there is lust in love and love is lust.
This emotion was developed mainly due to how humanity grew as a species or well a species that we know of right now. For most of the years in our existence love has been a more common emotion mainly in the old times but right now, in the complex society we live in have taken our caring and loving minds and broken them and reassembled them into something that is more of a machine than it is something to process emotions.
But
Love still exists
