University of Cambridge zoologist Arik Kershenbaum, in his new book, “The Zoologist’s Guide to the Galaxy,” states that life on earth offers a model for life on other planets.
Kershenbaum says that the “universal laws of biology” will always dictate what life looks like on earth and on other planets, specifically highlighting Charles Darwin’s natural selection, the basis for evolutionary biology.
Kershenbaum writes that a version of natural selection will play a role in the development of life regardless of alien biochemistry or planetary environment. This would naturally steer alien evolution to a limited number of possible outcomes. As a result, alien life would look a lot like life on earth.
According to Kershenbaum, most aliens would be bilaterally symmetrical and use something like legs, paddles or jets to move forward. He is equivocal on means of reproduction.
To read the DNYUZ piece on the book, here is a link.