Today I’m here to talk about the number one weirdest science fiction assertion made by Holly Kearny yesterday.
Aliens will be like us.
You can find examples of this bad assumption in such beings as: the time lords from doctor who and pretty much everyone from star trek.
The fact is however, that if you look at even the one data set for evolved life that we have (earthbound life shares a single common ancestor) there is already enough differentiation to really set some deep seeds of doubt in this assertion.
For example, cephalopods (the class of molluscs that includes octopi) have rather large brains and yet look completely different to us, with a body plan that allows for many versatile tentacles, ink and many other features. It is unlikely that these creatures will ever crawl out of the sea and start building cities.
This example also demonstrates (however oversimplified it may be) how bipedalism is not necessary for intelligence, it is unlikely that every intelligent species in space would have legs, never mind have two of them.
And even bipedalism isn’t a safe bet for being human-like.
Theropod dinosaurs, birds, gibbons and kangaroo rats all walk or walked on two legs and retain very different features.
And along with this, the same change of using two legs for features other than walking occurred within many-legged species such as the preying mantis and the lobster.
So now we’ve established that intelligent life could essentially be a blob of cytoplasm and make just as much sense as most science fiction aliens.
However, this doesn’t quite go far enough, as the molecular structure of all earth-based life is very, very similar.
How likely is it that life from another planet would evolve in such a similar way?
Would extraterrestrial creatures even have DNA?
With one single data point we don’t really have much to work on at the moment in the case of speculating the molecular biology of intergalactic beasts.
In fact if you remember how closely related we are to mushrooms (animals split of from fungi very recently), it could be that there could be nothing else in the universe that his evolved anything close to a brain.
If the environmental pressures don’t work in the direction where a brain will be favourable, a brain will not develop, it just wouldn’t be an advantage.
There’s a nice chunk of biology for you.