In "They Came From Outer Space: Real Aliens" (originally published in the Winter 1997 SFWA Bulletin), Molvray points out that extraterrestrial life would likely evolve under the rules of natural selection, just like life here on earth.
The first rule of biology is that life evolves by natural selection. Characteristics that help an organism survive and reproduce get passed on to the next generation. Conversely, any characteristic that increases mortality (either of parents or their offspring) disappears with the individuals it did not help. Except for worlds run by angels or genetic engineers, even aliens will be ruled by natural selection. Though this may seem obvious, the implications are rarely considered. What would be wrong, for instance, in describing an alien species as having three eyes--just to make them a tad more weird?She goes on to discuss how alien anatomy and physiology would necessarily be intertwined with the environment in which they evolved. She concludes:
Their biology is the sum of millions of responses to natural selection. Their minds will be based on their biology and ecology. Their cultures will be influenced by their biology as well as their dreams. If the reader gets to glimpse the forces that shaped them, those aliens will feel real.Molvray's web site also has a section devoted to biological factors in the evolution of intelligence. This is set up in the form of a course at the level of advanced high school students or college freshmen. It's got great material if you are interested in the question of whether there is other intelligent life in the universe.
Finally, read one of her short stories, "They Toil Not", and decide for yourself if her extraterrestrials seem realistic.
* She has a nice section on her site about the Catalina mariposa lily. And be sure to check out her fantastic photos on flickr.
Tags:science fiction, alien biology, extraterrestrials, intelligence