*whistle* Okay, but for I start let me lay out my ground plan here. The creation of the universe is random, the development of life even more random, and the evolution of true sentience incredibly more random: no creators, no original designer. Each of these events has an infinitesimally small chance of happening, each even more so than the last. All of it is statistically impossible, including and especially us.
That being said, no. The odds of them existing as KA describes are beyond numerical comprehension. However, hope springs eternal
Now from a biological stand point, which has no regards for me or my math, each species may have something to it. So here's my break down of some of them
Taxxons: Maybe. Large numbers make sense if you are killed pretty readily, especially by your own kind, and I can also see the hunger thing develop. The body is iffy to me however. It seems like they have an exoskeleton, and that type of body plan is hard to come by in large terrestrial creatures. For locomotion and where they live I'd say sure, but if it's that big an exoskeleton shouldn't support it well. Although perhaps they're skeleton would be comprised of a protein strong than arthropod exoskeletons, which given my ground rules, is probably more likely than them being the same.
Hork-Bajir: Yes. Obviously designed to be perfectly adapted to their niche. Reproduction concerns me, but I don't know enough about theirs to say more. And of course, everything is depends on the environment. So long as the right type of trees can exist, the Hork-Bajir should be okay, not the case if they only have the trees like the one in your living room this week.
Andalite: No. A large warmblooded creature that feeds by absorbing grass nutrients by merely crushing it seems far-fetched to me. A creature that size with fur, muscle, bone and whatever the tail is made of regulated by I think two hearts; that's a lot to sustain if you consider that Andalites aren't constantly feeding. Most grazers spend most of the day everyday eating and even if they eat while just normally walking around (which doesn't
seem to be the case from what we've read), no metabolic process is 100% efficient, you spend all that energy walking around to crush new food with hooves of only so large a surface area, to me that's a push. Plus, maybe I'm looking at it the wrong way, but walking over grass seems to do more harm that just eating it. You can mow a lawn once a week and it'll be fine, but you walk a path over it x times every so often it suffers, and since they no longer migrate, that seems like Andalites should all be starving to me.
Yeerks: Yes: It's known that some parasites can control their host via hormones, to control the nerve center is a obviously a bit different, but probably more complete. And assuming it has a capable host, the mortality rate is probably much better in the host than out, plus you could set up host for future generations. So parasite brain slug yes, but for the sentience thing, see below.
All of the above was just some general physiological stuff. When it comes to any species being sentient, well that's harder. Under my ground rules, it has to be a developed character, and the odds of that are slim on it's own, I belief, in any and everything. However, once there it should be a highly valuable, self perpetuating trait. It's getting there that is problem, and when it would occur, before, during or after the aliens as we know them is indeterminable.
I probably over and under did it all I once, but yeah. Odds of any particular thing are between slim and none, and probably closer to none. The thing to keep in mind for all of it though is that while natural selection for a trait is not random, the mutations that bring about the good or bad variation more or less is.
For being like yeerks, the odds of becoming a neural parasite over millions of years is probably small, but if you do, and it works, than it's good reason to suspect they could very well exist. Seriously, even with the quadrillions of stars and planets out there, the odds of any of these things out there should be dismal, but you could say the same thing about life on earth, the human race, and each of us individually. There's some other points in this to hit one but I'm drawing a blank for now, but yeah. Fun question
That ends my senior thesis for biology- I mean my post
