Apparently Fermi had a version, too.

http://praxtime.com/2013/11/25/sagan-syndrome-pay-heed-to-biologists-about-et/

A good starting point is Stephen Webb’s book “If the Universe Is Teeming with Aliens … WHERE IS EVERYBODY?: Fifty Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life.” It’s a fun romp through the history of the Fermi Paradox. From page 23: “it was a 1975 paper by Michael Hart in the Quarterly Journal of the Royal Astronomical Society that sparked an explosion of interest in the paradox. Hart demanded an explanation for one key fact: there are no intelligent beings from outer space on Earth at the present time.” Hart’s explanation was “we are the ﬁrst civilization in our Galaxy.“

Hart’s 1975 paper is short and clear, and worth a quick read. Hart runs various scenarios, but for me the key insight is one of time scale. It takes (only) millions of years for intelligent life to completely fill the galaxy, but billions of years for it to evolve. So first out the gate should be everywhere before second out the gate. Logically if ETs exist they should be here. And they aren’t. So case closed. The Fermi Paradox literature since Hart could arguably be characterized as nonstop special pleading to avoid a common sense conclusion.

I hadn't seen this argument before:

And as quoted in Mark A. Sheirdan’s book, we have eminent Evolutionary Biologist Theodosius Dobzhansky (“Nothing in Biology Makes Sense Except in the Light of Evolution“) joining the fray:

In his article Dobzhanksy turned Sagan’s argument on its head. Dobzhansky cited the fact that of the more than two million species living on Earth only one had evolved language, extragenetically transmitted culture, and awareness of self and death, as proof that it is “fatuous” to hold “the opinion that if life exists anywhere else it must eventually give rise to rational beings.”

Now we’ve nailed it. It’s Evolutionary Biologists versus Astronomers.

:-)

See the original for lots of embedded links.

(via Sean Carroll on G+ - https://plus.google.com/u/1/118265897954929480050/posts/PCTANMoxvb3 )

Cheers,
Scott.

(Speculation is that the growth to 'sentient adulthood' (after the first denizens multiply) is as iffy as right-here contemporary problems.)

How do you accelerate from some basic sentient inroads towards (adult-level for that species?) Can we improve on the n-billions years postulate
--from scratch/microorganisms--> to a level capable of launching asexual-reproducing robots for exploration?
Or, let's go down quite a few orders-of-magnitude--you'd think that would be simpler, no?

How do you get.. already well-developed creatures, most often engaged in trying to emulate kittens-at-play -vs- doing any chores, (especially assigned-ones?)
like, oh say: cleaning the litter-box; then preparing for imminent days: calculated to become too-hot to be outside. (While you still can be outside.)
and also too--before your common foods have also wilted ... and a few thousand other things that aren't what you wished-for.

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