It could be love isn't here for any reason or advantage, it's just a thing that happened that is not enough of a disadvantage to be bred out yet. Because that's how evolution works: a large number of things pop up, and some of them that don't work get bred out, and some that aren't a bother but aren't an advantage either stick around, and some that are an advantage last longer. Love might be a thing that just happened that isn't enough of a bother yet.
<3 <3 <3 xoxo
Things don't just happen in evolution.
For love to have out-replicated nonlove as hard as it did (it's at fixation) for as long as it has (it's present in many other species), it needed to either piggyback on some other useful thing or be useful itself.
My favorite sequence post, although it's only good in the context of dozens of other important posts.
Today's post, The Gift We Give To Tomorrow was originally published on 17 July 2008. A summary (taken from the LW wiki):
How did love ever come into the universe? How did that happen, and how special was it, really?
Discuss the post here (rather than in the comments to the original post).
This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was Whither Moral Progress?, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.
Sequence reruns are a community-driven effort. You can participate by re-reading the sequence post, discussing it here, posting the next day's sequence reruns post, or summarizing forthcoming articles on the wiki. Go here for more details, or to have meta discussions about the Rerunning the Sequences series.