The July issue of Smithsonian has a great article about genealogy. Unfortunately, I don't think it's posted online, but it's worth buying the issue or tracking it down at your local library. "The Family Tree, Pruned" by Richard Conniff isn't about adoption specifically and, in fact, doesn't even mention adoption, but the message of the article is perfectly suited to adoption. The author's daughter apparently spends a lot of time with her genealogy projects, yet the author contends that genealogy is relatively meaningless. He sums it up nicely in the closing paragraph of a fairly long and well-written article:
"What makes us who we are, what makes us people worth knowing, comes from within ourselves, and from the often annoying, somewhat laughable, occasionally lovable families we live with now."