Exo-evolução: extra-terrestres que se escondem são os que sobrevivem

segunda-feira, abril 11, 2011

Exo-evolution: Aliens who hide, survive

17:39 08 April 2011 by Mark Buchanan

For similar stories, visit the Astrobiology and Evolution Topic Guides

An evolutionary catastrophe? (Image: Kevin McCoy)

Has ET evolved to be discreet? An evolutionary tendency for inconspicuous aliens would solve a nagging paradox – and also suggest that we Earthlings should think twice before advertising our own existence.

As physicist Enrico Fermi argued in 1950, unless the evolution of life is unique to Earth, there must be many intelligent species out there. So why have they neither phoned home nor been detected by us?

"It's a real paradox," says Adrian Kent of the Perimeter Institute in Waterloo, Ontario, Canada.

In order to explain the Fermi paradox, Kent turns to natural selection – and suggests that it may favour quiet aliens.
Violent universe

He argues that it's plausible that there is a competition for resources on a cosmic scale, driving an evolutionary process between alien species on different planets. Advanced species, for example, might want to exploit other planets for their own purposes.

If so, the universe would be a violent place, and evolutionary selection may favour the inconspicuous – those who lay low on purpose, or who simply lack the skill or ambition to venture forth or advertise their existence.

"This is an interesting idea," says alien hunter Seth Shostak of the SETI institute in Mountain View, California. "If I let the cosmos know I exist, then I might be subject to extermination."

However, he is wary of assuming a "straitjacket" on the activities of intelligent species, who might not be able to resist the intellectual pull to develop advanced technologies detectable by others.

"If interstellar violence is possible, the bad news is that all societies are required to constrain their endeavours to activities that could never be detected at a distance," says Shostak.

Read more here/Leia mais aqui: New Scientist


Article mentioned/Artigo mencionado:

Too Damned Quiet?

Adrian Kent (DAMTP, University of Cambridge and Perimeter Institute)

(Submitted on 4 Apr 2011)

Image not related to the article/Imagem não relacionada com o artigo


It is often suggested that extraterrestial life sufficiently advanced to be capable of interstellar travel or communication must be rare, since otherwise we would have seen evidence of it by now. This in turn is sometimes taken as indirect evidence for the improbability of life evolving at all in our universe. A couple of other possibilities seem worth considering. One is that life capable of evidencing itself on interstellar scales has evolved in many places but that evolutionary selection, acting on a cosmic scale, tends to extinguish species which conspicuously advertise themselves and their habitats. The other is that -- whatever the true situation -- intelligent species might reasonably worry about the possible dangers of self-advertisement and hence incline towards discretion. These possibilities are discussed here, and some counter-arguments and complicating factors are also considered.

Subjects: Popular Physics (physics.pop-ph); Space Physics (physics.space-ph)
Cite as: arXiv:1104.0624v1 [physics.pop-ph]

Submission historyFrom: Adrian Kent [view email
[v1] Mon, 4 Apr 2011 16:48:35 GMT (14kb)