© 1975-1979, 2008 Robert A. Freitas Jr. All Rights Reserved.

Robert A. Freitas Jr., Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, First Edition, Xenology Research Institute, Sacramento, CA, 1979; http://www.xenology.info/Xeno.htm

14.1  Evolution of Intelligence

We may perhaps glean some insight into the evolutionary processes underlying the emergence of intelligence by examining how human intellect arose on Earth.* While details may differ from planet to planet, the outcome of mental evolution elsewhere in the universe should be at least functionally similar.

* What is the optimum body shape for sentient ETs? Scientific opinion remains sharply divided on this question, and two schools of thought have emerged. The pro-humanoid camp (including Bieri,¹⁷⁰⁶ Blumrich,¹⁰⁵⁸ Campbell,¹³⁸⁰ de Camp,²⁵⁷² Fletcher,¹⁹³⁵ Howells,³³⁰ Hynek,⁵⁹⁷ Ley,²¹² MacGowan,⁶⁰⁰ Ordway,²⁵⁷¹ Puccetti,⁷¹ Rall,⁴⁴⁵ and Spall¹¹³⁷) claims that the primate form is best for tool-using aliens. The non-humanoid camp (see Blum,¹⁶⁶⁸ Broms,¹¹⁹¹ Clarke,⁸¹ Dobzhansky,¹⁷⁰⁵ Eiseley,¹³⁵ Huygens,⁶⁰² Muller,¹¹⁸⁴ Oparin,¹⁵⁵⁸ Ornstein,³²⁷ Ruzic,⁵⁵⁹ Sagan,⁸⁵ Shapley,¹⁵⁵⁴ Simpson,³³⁴ Vertregt,¹¹⁷¹ and Wald⁸⁶⁷) holds that the human form is a unique evolutionary accident that will not be repeated elsewhere. (There is also a middle-of-the-road camp, such as Anderson,⁶³ Gardner,¹⁵⁵⁵ and Molton,¹¹²⁹ but this is a minor faction.) The debate has raged for decades, and will not be detailed here. Suffice it to say that the humanoid form is a very useful one, so it probably will not be rare. Whether it will be common remains an open question.

Last updated on 6 December 2008