the hungry earth or the gorn hegemony

Inspired by and named for a 1970 Doctor Who story-arc that originally aired from this day until 14 March on BBC1 in weekly installments wherein the Third Doctor tries to broker a peace settlement between the simians, sapiens and the reptilian Silurians who were the dominant intelligent species, the eponymous hypothesis is an interesting and self-critical (though sometimes coopted by fringe elements and regaled with the hallmarks of pseudo-science) thought experiment, a corollary to Fermi’s Paradox in a sense, to gauge those simian successors’ ability to detect evidence of prior (or parallel) advanced civilisations.
Formalised and fleshed out just in 2018 in a paper by astrophysicists Adam Frank and Gavin Schmidt, they pondered whether there would be any sort of trace of industry, given sufficient time and distance and divergence from our own manifestly self-destructive and unsustainable technology, a civilisation that produced less enduring waste and had a lower profile in terms of environmental impact would be harder to dig up but would probably be the more successful and longer-lived for it as well.  Any artefacts, direct or indirect, could prove elusive indeed, and we may be incapable of recognising them for what they are. Please be sure to visit Futility Closet at the link up top for an abstract and the full paper.