Verify work via public PGP key?

[smakme7757]

Hi folks,

I was reading this article:
http://internetcensus2012.bitbucket.org/paper.html

and at the end the author has added his public PGP key to prove that it was indeed him that has created the content.

I am however wondering how it's possible to validate the article? How do we know it hasn't been edited? and how can we prove via his public PGP key that it was him that wrote it?

I'm used using PGP in the following way:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

This post was created by me
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (MingW32)
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=nuuk
-----END PGP SIGNATURE-----

So if you have my public key you can verify the contents.

However he has just given us his public key so i'm not really sure how we can identify him through just that or the authenticity of his article?

Thanks in advance

PS: was an interesting read none the less!