As a life-long science fiction fan and an aspiring evolutionary biologist, I have given a great deal of thought to the presence of extra-terrestrial life. For the purposes of this blog, I am going to assume that extra-terrestrial life exists somewhere in the universe. To all the party-poopers who would argue with me I have several points to make: 1) The universe is vast and among all the uncountable combinations of stars and planets and moons, it is likely that there is a planet similar to Earth orbiting a star similar to our Sun somewhere out there. 2) Life evolved on this planet relatively quickly considering how complex and strange our basic chemical makeup is (DNA is nothing short of astounding when you examine it closely!). Meaning that life may take a while to happen but it could happen on any Earth-like planet. 3) It’s just more fun this way! Also I really don’t want to argue creationism with anyone, so if you try to make this post about your religious beliefs rather than a science-fiction-y exploration of complex life, I will ignore you.
Given this assumption that extra-terrestrial life exists, the next question is what would it look like? What kind of adaptations would an alien species exhibit? By looking at our own evolutionary history we can throw out some ideas about what we might see upon encountering this alien race. Unfortunately, I speak Bio-Geek almost exclusively so I need to define some terms so people will understand me. First, evolution is the total processes resulting in species differentiation, including natural selection (survival of the fittest), mutation (survival of the freakazoids), genetic drift and bottlenecks (survival of the lucky). Second, convergent evolution is when two species in different groups evolve some characteristic for generally the same purpose but from different starting points. The classic example is flight. Flight has evolved in at least three different groups on Earth (birds, bat and insects) for the purposes of escape from predators and pursuit of prey. Convergent evolution is important because it means that the evolutionary pressures driving a species, towards flight for example, are fairly consistent and we can generally assume they would be consistent on another planet. Third, stochasticity is randomness or unpredicatability in processes. The prevalence of stochasticity basically means that if we should meet aliens tomorrow, I cannot be held accountable for the differences between my predictions and reality.
In this blog I intend to point out some chemical and biological factors which are assumed to be present in any ecosystem based on logic and a basic knowledge of science. As you can probably guess, I also intend to make some loose predictions about alien life by examining convergent evolution in our own evolutionary history. (I’m already giddy about it!) We are only likely to meet intelligent races (at least until we figure out that pesky FTL drive) so I’ll give some thought to the origins of intelligence. Finally, I’ll take some of my favorite examples of aliens from sci-fi and explain why I think they would or wouldn’t exist on a “real alien planet”. I would welcome discussion about the topics I propose (if anyone actually reads this blog) but please keep it civil and off the topic of evolution vs. creationism. I am sure there are other bloggers that would love to argue that particular point with you.