I will show you species death in a handful of single-celled organisms

Here's one fearful look at the search for extraterrestrial intelligence:

if we discovered the fossils of some very complex life-form, such as a ­vertebrate-­like creature, we would have to conclude that this hypothesis is very improbable indeed. It would be by far the worst news ever printed
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I'm hoping that our space probes will discover dead rocks and lifeless sands on Mars, on Jupiter's moon Europa, and everywhere else our astronomers look. It would keep alive the hope of a great future for humanity.

Why?  The author elaborates on the theme of The Great Filter of life, and why it would be best for it to be behind us.  Read on.