Now, I would like to turn my attention to the engineer’s role in the origin of life on planet earth. Before I go any further, I would like to say a few things. My main intention of this exercise is not only to try to find a connection between the events in Prometheus and the plot of Alien, but, also analyze my hypothesis under the context of what we know scientifically today. For instance, genetics is a well developed science and the question of origin of life has been tackled for a very very long time by a large number of scientists. Although, there is no solitary, definitive theory at the time of this writing, there are a few that appear to be highly plausible. I hope you folks get my drift. Analyzing the movie with the help of scientific facts, whenever possible would be a recurring theme of my hypothesis. More exhaustive details of the scientific aspects below can be obtained from Wikipedia, if anyone is interested.
OK, let’s move on to the scene where the engineer consumed the black goo and ended up being a catalyst for the origin of life (I have to admit, I loved it that they decided to call these beings, Engineers. I don’t think its necessary to talk about the difference between engineering and creation). This black substance is probably the most mysterious thing in the whole film. It is the thing that holds the whole movie together, plotwise. Hence, it’s notoriety needs to be analyzed exclusively in a separate post later. So, for the time being, let us look into the aftermath of its consumption. It resulted in rapid disintegration, even down at the molecular level. The biological material mixed with water and then we saw emergence of cellular structures.
When you consider the scientific theories regarding origin of life and the above scene together, things get pretty interesting. Assuming that there was no other intervention by the engineers after the onset of that event, then, one can safely concur that environmental parameters made sure that evolution of life progressed in its natural pace, thereby resulting in human development.
Time Frame – Engineer’s Intervention
As I mentioned earlier, there have been multiple theories put forward to explain the origin of life on earth. What most of these theories agree upon is the fact that there are strict regulations as far as the emergence of perfect conditions for life is concerned. So, you see, this problem relates all the way back to formation of Earth. With this in mind, let us first try to establish a rough time frame when the engineer sacrificed himself. One thing we can all agree upon is the fact that our planet is nearly 4.6 billion years old. In terms of geological eons, the period roughly between 4.5 billion years and 3.8 billion years is called the Hadean. It was a period, when Earth was extremely violent. A primordial atmosphere would have existed due to volcanic outgassing, but completely devoid of Oxygen. It was molten due to intense volcanic activity and collision with other bodies. It is also suggested that plate tectonics had existed at around 4 billion years that would support the existence of oceans at that time already. Now, what of life? Given the harsh conditions on the planet, it is theorized that life could not have formed during this eon. Could building blocks for life had existed by then? May be, may be not.
The next, most important eon that has relevance to Prometheus is the Archean. It dates roughly between 3.8 billion years and 2.5 billion years. Simply put, by this time, Earth had cooled significantly and the conditions were suitable for the formation of primordial life. Cyanobacteria, commonly called as blue-green algae are supposed to have existed nearly as back as 3.5 billion years ago. The exact time period when photosynthesis capability evolved is something that is still under debate. The problem being, geologic record indicates that this event took place around 2.5 billion years ago. But fossil records of Cyanobacteria indicate that they had existed as back as 3.5 billion years ago. You must be thinking, well what has this discrepancy got to do with Prometheus? Trust me, I am getting there.
Revisiting my earlier assumption that the engineers intervened only once, my hypothesis is that they visited our planet roughly during the early Archean time period, say around 3.9 or 3.8 billion years ago. Now getting back to photosynthesis, it creates a problem. In the beginning of the Archean eon, the atmosphere had no free Oxygen. The ability of cyanobacteria to perform oxygenic photosynthesis was the precursor for the replacement of reduced atmosphere to an oxygenated one (It’s much more complex and it involves a delicate relationship with Iron and unoxidized Sulfur, amongst many other things) that resulted in the emergence of complex multicellular life. What bothers me though, is the following. If my assumption about the timing of the engineer’s visit is sort of correct, then how come the engineer has no problems breathing on earth when the atmosphere has absolutely no Oxygen?
If he had visited, say 2.5 billion years ago, it would make little sense. He would then be directly intervening with already evolving life on the planet. But, that’s not what the first scene is suggesting. To me, it looks like the formation of primordial life and the subsequent evolution of multicellular organisms.
But, there are a few shots in the film that seem to suggest the post oxygenated atmosphere timeline, but it is a bit difficult for me to reason with. True, it’s fiction and all, but hey, I can speculate, can’t I? I will add a special post about these discrepancies.
Engineer Driven Evolution of Life
Now, lets tackle the question of formation of life due to the engineer’s sacrifice. From a scientific standpoint, this question has fascinated many brilliant minds, since time immemorial. This broad question can be normally classified under two categories: 1. How did organic molecules come about? 2. How is a protocell formed from these organic molecules?
1. Organic molecule Origin
There are basically two possible sources on early earth, namely, terrestrial origin – that organic synthesis is driven by an external energy source, like, lightning, UV light etc., and extraterrestrial origin – meteorites, accumulation of organic molecules due to gravity or by Panspermia (the idea that life came from an extraterrestrial source in the form of bacteria trapped in debris that crashed in earth, for instance, that simply became active when the conditions were ideal for life and resulted in evolution). Within these two frameworks there are many theories that explain the origin of organic molecules. But, I am not gonna go through them. There are theories like Soup theory, Eigen’s hypothesis, Hoffmann’s thesis, Wächterhäuser’s hypothesis, Zn-World theory and many more.
2. Origin of Protocell
Again, there are multiple theories that have tried to explain this transformation. Deep sea vent theory, RNA World Hypothesis (gene first), Metabolism first theories are the main ones. There are others like, Autocatalysis, Clay hypothesis, Deep-hot Biosphere model, Primitive extraterrestrial life model, Lipid world models etc.
Based on the developments in Prometheus, I was faced with a couple of questions – 1. What models are best suited to further my hypothesis? 2. At which level did the intervention happen? Did the defining event happen before the synthesis of organic molecule or did it occur before the protocell synthesis? If I was interested in preserving my blueprint, I would like to have complete control over the process, hence, I would start at the very beginning. Therefore, my hypothesis is that the engineer intervention actually gave rise to organic molecules on Earth. Exogenesis, another theory that accounts for the extraterrestrial origin of organic molecules, but does not explicitly state how (Main difference with Panspermia), is the best theory then to explain the events of Prometheus. Now, what we have under this condition is not just organic molecules, but also the genetic history of the engineers in one form or another. Now, what of the second step – the formation of protocell? Let us analyze.
This step is extremely important in my opinion. This is exactly where the intervention of the engineer gets amplified and the genetic code is conserved all the way through human development (Shaw finding a match between human and engineer DNA). As outlined earlier, there are many theories that have been proposed to explain this step, but as far as the movie is concerned, I am looking at the RNA world hypothesis. Scientifically, it is currently popular in explaining the formation of protocell. Simply put, the theory states that in prehistoric earth, self-replicating, catalytic RNA formed and served as the precursors for emergence of life. It should be noted that there were no DNA and proteins at that time. Several hypotheses have been proposed for the spontaneous formation of RNA molecules. We all know that RNA can also store information, although not as efficient as DNA does. It also plays a crucial role in enabling DNA’s ability to maintain this genetic information. It was the great Francis Crick, Leslie Orgel and Carl Woese, who first hypothesized that RNA could act as a catalyst. Then, in 1980, Thomas Cech discovered ribozymes, a RNA molecule that can catalyze a chemical reaction. In addition, ribozymes have been produced in labs that can catalyze their own synthesis.
Speaking of Francis Crick, he and Orgel in the 70’s speculated living systems could have been spread here by intelligent life forms using space travel. They called this “Directed Panspermia”. The reasoning then was only proteins were the only known enzymes and ribozymes hadn’t been discovered. The existence of complex replication processes in organisms currently on earth puzzled scientists who couldn’t explain how such complex self-replicating units could have originated in prehistoric life. Crick and Orgel published a retrospective article on January 1993, reflecting on their theories from the early 70’s and how it has been affected by the discovery of the ribozyme. If you are interested, just click on the following link for direct download of the pdf document.
Life today, is DNA-centric as far as information is concerned. It’s simply because the large size of RNA makes it limited for information storage as it is energy intensive to repair any damage and mutation. But, it might have been a different case in prehistoric life. It has also been observed that many critical components of the cell, especially the ones that evolve the slowest, are entirely made up of RNA. Could that mean that the modern RNA is an evolutionary remnant from a prehistoric time? There’s a large body of evidence, with the most recent from August 2011 that really points towards a RNA world hypothesis. Hopefully, more information should emerge in the coming years.
Based on all this, my hypothesis is that the engineer’s organic remnants created an accumulation and creation of more organic molecules (amino acids, for example), followed by formation of self replicating RNA molecules (where the genetic blueprint of the engineers are somehow conserved), which then resulted in emergence of life.
I would like to apologize for rambling about RNA, geological eons and so on. I could have simply written that the engineers paved the way for the evolution of life on planet earth. But, I just thought it was fun doing it the way I did. If, at least one visitor found the information interesting and took a shining to learn more about things like RNA world hypothesis, then I have done my job.
Anyway, for the bored readers, let me put forward my hypothesis in a few sentences. Engineers arrived on Planet Earth around 3.9-3.8 billion years ago. The disintegrated engineer was the source for organic molecules on the planet (exogenesis). Protocell formed from self-replicating RNA molecules bearing the genetic footprint of the engineer. Evolution proceeded in its natural pace leading to human development.
Finally, going by the above theories, would it make sense to say that the black goo is some type of a rapid reverse-evolution catalyst? It is capable of causing absolute breakdown to biological precursors that would be capable of re-evolving under favorable conditions anywhere in any planetary system, but at the same time somehow preserving the genetic history. This genetic template can be manipulated at any instant of time by the original inventors of the black goo to re-engineer a complete race, say for example, when threatened by extinction or fertility issues? Just some rambling thoughts. I will have a detailed post on the black goo discussing in detail all of these elements.