In line with that idea, here’s the stream of thoughts that kept me up to 3AM last night (new to the forums so please excuse the “wall of text” for my inaugural post :)):
Overall, I think RDM & Co. did about as fine a job as any serialized science fiction series ever has at bringing everything to a satisfying conclusion. Two things stick in my mind as substantial problems big enough to pull me out of my fuzzy glow, though.
Hera as “mitochondrial Eve” and the colonists as seeds of civilization. Someone should have brought a biologist and an archaeologist in to consult on this finale reveal becuase there is a schizophrenia here that just doesn’t work without invalidating one or the other premise, and maybe both (I am a biologist so I figure I can quip with some knowledge of at least half the problem). The mitochondrial Eve theory works because you have a point origin for Homo sapiens. At some period in our particular species’ lineage, a population bottleneck of such severity occurred that, as best we can tell, every human living today sprang from this small group of (proto) humans with a common maternal lineage. The problem here comes in if we are to accept the implication (that the show all but hits us over the head with) that this mitochondrial Eve is literally Hera. The key problem is obvious: if we accept that Hera is mitochondrial Eve, this means that within a few generations of the colonists’ arrival on ancient Earth that there isn’t one living female who can’t trace a direct line back to Hera. The tribal humans they discovered? Gone. The roughly 19,000 surviving females from the colonies and their daughters? Gone. Remember, it’s a severe population bottleneck that created mitochondrial Eve, as in something so reduced the numbers of early humans (or early ancestors of humans) that not one lineage not traceable back to a common maternal ancestor survived after this bottleneck. This creates a mutually exclusive dichotomy: either Hera is not, in spite of the show’s very strong implication, literally mitochondrial Eve, or the colonials are not, in spite of the show’s almost equally strong implication, the seeds of ancient civilizations and peoples.
Both premises cannot be true. You can’t have humans going to what will become ancient Asia and Australia in addition to Africa and still wind up with Hera as the mitochondrial Eve without some harsh implications. Long distance travel would have stopped within a few years after their arrival, if even that long, once whatever fuel they had with their handful of raptors was exhausted. That means no gene flow between these regions. No gene flow means one of two things, either both the Asia and Australia colonizations were complete failures in the short term, or descendents from Hera’s lineage eventually migrated out of Africa and utterly exterminated the descendents of these other two colonial seedings (not a very constructive way of breaking the cycle). Now, since RDM is, once again, late with the podcast, perhaps he did intend the former explanation, that only the Africa colonial seeding took, but even that holds the harsh implication that out of the ten to fifteen thousand colonials who went to ancient Africa, never mind the already existing humans that were living there, that only the line of Hera survived to modern day through what can only be considered an even worse series of circumstances than what brought the colonials to our Earth in the first place. If we are to believe that Hera is the literal mitochondrial Eve, that means their plan to start over doesn’t exactly work and the majority of the colonials and their descendents, along with the humans that evolved naturally on our Earth, all get wiped out in short order after the colonials arrive. That may indeed be what RDM & Co. intended, but, if so, it’s a very, very dark scenario filled with a lot of suffering and genocide and not at all the optimistic clean slate the dialogue implies.
Admittedly, we do know our own history, and perhaps their optimism for a clean slate to break the cycle quickly dissipated by unimaginable death and despair over the next half century is exactly what the show creators intended. However, there is another set of possibilities that are suggested because the Hera as literal mitochondrial Eve mechanic has more than a few inherent weaknesses and/or loopholes. Mitochondria possess their own genome, are inherited directly from our mothers, and change very slowly relative to human genomic DNA; hence, the whole concept of being able to trace human lineages back to a mitochondrial Eve in the first place. The most obvious thing that comes to mind is that the odds are that all of the cylons possess genomically identical mitochondria. Creation of a functioning synthetic cell is not a trivial exercise, it’s certainly far outside our current technology. It is probable that all of the cylon “skinjobs”, and maybe all of the bio-organic Cylon elements, would have been derived from a common synthetic cell line. If so, then all of the remaining Six and Eight models had the potential to replicate the success of Helo and Sharon with surviving male colonials and Earth evolved tribal males (not to mention that Helo and Sharon might have provided Hera with sister “Eves”). The pairing of Baltar and Caprica, finally correct in its equation of love and respect, is an obvious example in the storyline that might have given rise to more cylon-human hybrids. In this scenario, Hera is merely the figurehead for the mitochondrial Eve since all male human-female cylon pairings would have an identical mitochondrial genotype (at the very least, all children from other Eights would). Under these circumstances, it is the hybrid vigor resulting from the combination of both naturally evolved and synthetic human genomes that could survive on ancient Earth to the exclusion of all other homonid lineages. So, while the mitochondrial lineages of the female colonials and native Earth humans may indeed have been competed out of existence in short order, it’s not quite the doom and gloom everybody dies scenario that Hera as literal mitochondrial Eve requires. This is my favored explanation since it allows us to accept both the colonials as seeds of Earth humanity and the important role, real and symbolic, of Hera for the future.
A secondary line of thought is that we should also consider what I just wrote along with the fact that we know the colonials have experienced not one, but two, severe population bottlenecks of their own, the fall of Kobol and the fall of the colonies themselves. It is conceivable that at least some colonial and cylon mitochondria are genomically identical under these circumstances. If you were going to create a synthetic cell, you would almost certainly start with parts from natural cells. With a severe population bottleneck just some short thousands of years prior to the start the BSG storyline, there might very well have already been only a few (or even just one) distinct mitochondrial genotypes during the time of the colonies. One of these mitochondrial genotypes is most likley what would have been appropriated for creation of the cylon cell lines. If true, then we could still have the modern discovery of mitochondrial Eve within the field of molecular biology but never know that she existed somewhere back on ancient Kobol. However, I am less enamored with this scenario because it removes the importance of Hera. I suspect if the show creators did think their mitochondrial Eve ramifications out, as they should have, it is my first fanwank that is what was intended.
A final problem is in the time period of the colonials’ arrival. The arrival at 150,000 years ago becomes necessary if the cylon-human hybrids as the progenitors of modern humanity is true. Hera, either as literal or figurative mitochodrial Eve, requires this particular date as it is around the time we can calculate the existence of the so-called mitochondrial Eve via subsequent changes in mitochondrial genotypes around the globe. However, there’s a bit of a problem in that this pre-dates agriculture and written language by well over 100,000 years. So, although the colonials talk about bringing language to native Earthers, and Baltar and Caprica have a touching moment over his farming expertise, we’re given a bit of a conundrum to swallow. Much as in the probably very ugly truth about what happened to all those tens of thousands of colonials and native Earthers if only human-cylon hybrid lineages survived to modern day, we have to ask what happened to these seeds of human civilization. Is modern archaeology simply wrong and the line of Hera maintained written language and agriculture throughout this 100,000 plus year discrepancy, or did the seeds of civilization die out within a few generations, if that long, and plunge the descendents of Hera into complete paleolithic barbarism until these technologies were rediscovered after an eon of total ignorance? The sunnier scenario isn’t entirely impossible since we were given the very explicit prohibition of building a new city from the colonials. Perhaps we are to accept that it wasn’t that agriculture and written language didn’t begin until roughly 10,000 years ago, but rather that no records due to no concentrated human settlements before this time exist. After an eon of living as seasonal farmers and hunter-gathers, the descendents of Hera have forgot their proscription against cities and began to gather once again and we have merely misinterpreted this evidence. I’m no expert on archaeology, so I don’t know if that fanwank is as plausible as my figurehead Hera as mitochondrial Eve fanwank, but I hope it is (otherwise I have once again analyzed myself out of totally enjoying a good story ;)).