I read John Lambshead's essay at the Baen site today and it got me wondering again how certain we can really be that civilisations didn't develop on Earth even many millions of years before us.
If exchange of ideas and transmission of cultural and technological records were communicated in movement or song, by tail and neck in sauropods say, and maybe constantly within and between large groups, rather like a more complex Occupy megaphone, and landscapes were transformed through cultivation only, would we have any more evidence than we do that we were not the first?
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