Dinosaurs In Space: Why The Hell Not?
I wonder how many of you remember what the ‘advanced alien dinosaurs from space’ story was actually about. I must confess to having a slight problem with remembering what the actual science was, and with good reason, because the science of the story had absolutely nothing to do with Argonians, Killercrocs or the extreme dinosaurs (or dino vengers). In fact the actual news item was about chirality (the way certain molecules are orientated around a central carbon atom; in biology we find that one orientation is dominant) and how amino acids from meteorites might have influenced its orientation in life on earth. However, here I’d like to discuss the likelihood of there actually being dinosaur-aliens out there in the universe using our only data set – earth.
First off, if you want to hear a much more professional outlook on this type of thing, PZ Myers did a great lecture at TAM 2011 on the subject of the expectation that intelligent aliens would look human. I watched the whole thing at it was endlessly fascinating, but evolution and the diversity it creates is one of my obsessions. Check that out below.
When we think about the concept of dinosaur-like creatures evolving on other worlds, it would seem that we are biased by earth, our single data point, and the diversity of creatures that evolution catalyzed on our planet over the millions of years it’s had to work its magic. It’s pretty difficult to shake this bias, and, possibly as a result of this, we rarely see aliens in science-fiction that don’t look familiar to us. Most are similar to one species or another that we know existed or exists today. It would appear that we humans aren’t as good at thinking outside of the box as we often give ourselves credit for.
In fact, the chances of creatures that resemble dinosaurs evolving in a second event of evolution is probably pretty low. When we think about the frequency of genetic mutations, how often those mutations would give the creature enough of an advantage to let themselves survive into the next generation (and extrapolating from that into the thousands of subsequent generations) and how many of these mutations would lead to something ‘dinosaurian’… well, the odds aren’t truly in favour of it, especially if you look at how many times dinosaurs have evolved on earth. Namely once.
For dinosaurs to evolve on a different planet we would need similar conditions to those that created the evolutionary pressure to become ‘dinosaurian’, the creatures already present before this conditions arose would need to be very similar to the creatures that evolved into dinosaurs on earth, and to lead to dinosaurs with the space-faring capabilities that the media would have us wonder about… well, there’d have to be some sort of pressure to remain exactly the same physiologically while becoming more intelligent and gaining opposable thumbs.
And that’s just silly.
I would also urge you to consider how rare multicellularity actually is. Dinosaurs were multicellular creatures that evolved from multicellular creatures that evolved from single-celled organisms. When we look at the extreme diversity of single-celled organisms to the tiny, tiny domain of multicellular life it seems like in general, well, being a single cell might actually be a much better strategy for passing on genes and therefore possessing more evolutionary staying power.
The only real advantage that space dinosaurs existing has is that the dinosaurs were a very diverse range of reptiles that took on many different shapes and sizes. This diversity means that the chances of some creature superficially resembling one of the many designs of dinosaur that were available for purchase in the mesozoic era is higher than say… the chances of something looking superficially human. But that’s not to say that the likelihood sees that much of an increase even when taking that into account. Superficiality is superficiality after all, and the fact that we don’t call chimpanzees jungle-humans probably says something about how likely we would be to class even the most dinosaur-ish creature we found ‘a dinosaur’. I use scare-quotes there because by nature of the fact that we tend to class species on relatedness rather than appearance, any dinosaur from space that evolved independently from the dinos we know and love would be by definition NOT a dinosaur.
Now ain’t that a kick in the teeth for all the sensationalists out there?
[Image credits: tumblr, tvacres, newspaper.li]