Evolving the Alien - Jack Cohen and Ian Stewart
The book is about the science of evolving workable theories as to what aliens (IF they exist and WHEN we run across them) would be like.
The authors discuss the science of "xenoscience", using whatever they can of terrestrial biology, astronomy and astrophysics.
The book also attempts to answer the question so many people asked me when I told them I was reading it - why?
Why bother? Apart from the nutcases who burble on about being "abducted", who has actually seen an alien?
Here are the book's and my reasons combined (because it's so hard to remember whos ideas are what in my raspberry jelly brain ):
1) If we (as in the Human Race) are ever going to intelligently look for signs of alien life, spaceprobewise or SETIwise, we should try and make an intelligent guess what to look for
2) While terra-forming or inter-planetary colonisation still looks more fictional than real at this point in time, we're not too far off from the point where discussions of the "environment" will have to be prefixed with a planetary name to be clear
3) If enough of us talk seriously about the subject, we might actually be able to beat some sense into Star Trek fans (on the plus side for trekkies, although the book doesn't look kindly on the aliens created in most sci-fi shows or movies, they provide a (plausible?) explanation for the evolution of "tribbles" - you do remember THAT episode don't you?)
4) Stepping back a bit from the view that Earth is the only planet which supports life and can
support life, helps us to understand life and the evolution of life better
The sweet pieces of the book for me are the small blurbs of SF novels they've sprinkled liberally over the chapters.
That and the eww-
gross delight I take in discovering just how weird
some creatures are - nasty frogs that feed on the tadpoles of their own species, fish that change sex as per convenience and an Indian (and I thought I was the only one) stick insect which has given up sexual reproduction as a means of reproduction.
If you have read this far, DON'T try and borrow the book from me - I've already got too many friends on Betelgeuse 7 waiting to get their tentacles on it.