Lost Worlds: Aliens from Earth?

Was there a technologically advanced species living on Earth long
before humans? And if one had existed, how would we know? This is
the first episode of our new four-part series, Lost Worlds. For
more, go to http://vox.com/unexplainable It’s a great place to view
show transcripts and read more about the topics on our show. Also,
email us! unexplainable@vox.com We read every email. Support
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