Environmental manipulation is indeed an observable consequence of sophisticated synaptic activity, but this ability is not unique to humans. The use of tools, a good rubric of environmental manipulation, is achieved from birds to dogs, from elephants to chimpanzees, from humans to Hummer drivers. Yet, the synaptic structure of different species, while seemingly identical at first electrophysiologic glance, can differ dramatically in their proteinacious scaffold. Further, the synapse alone may not fully explain organismal fitness in the same way that my Intel Core 2 Duo processor in my MacBook isn’t much good installed into my TI-83 graphing calculator from college: the hardware (i.e. neuronal architecture) isn’t compatible. So what is it, then, in the < 2% genetic difference between chimpanzees, our closest extant genetic ally, and ourselves that makes the differences between jumping onto a tree and jumping onto the moon? The answer may not be the synaptic tool itself, but how that tool is used.
With such a similar genetic portfolio between the chimp and human, the search for what makes us human is narrowed to the corners of our 2% genetic divergence from a common ancestor nearly 6 million years ago. Some of this divergence is a part of the “Human Accelerated Region,” or “HAR,” which is a fruitful, albeit small archipelago among a sea of genetic doldrums. The HAR archives genetic instructions ubiquitous to the Great Apes – even most vertebrates – yet unique enough in humans to prescribe distinct proteins with (proposed) distinct functions; it’s as though our current genome is the latest version of the ape software: v2.0 OS Human (because Apple ran out of cat names). Not surprisingly, much of the HAR’s archipelago resides within the brain’s governmental jurisdiction. It is here that our ursynaptic family tree first sprouted, and it is here that our human identity and its unchartered future may lie.The HAR is suspected to code only 49 proteins. This is compared to the tens of thousands, if not hundreds of thousands of proteins that comprise the entire human proteome. But given that we parted from our hairier-than-thou family ancestors a mere 6 million years ago (remember the ursynapse is nearly 1 billion years old), 49 proteins in 6 million years is a hedge fund with some high risk, high gain return. Literally. The risk in our beloved synaptic moxie is that it carries the baggage of an unrefined, imperfect system that can result in neural dysfunction. For example, there is no known correlate of schizophrenia or neurofibrillary tangles (Alzheimer’s disease) in chimpanzees, let alone in our more distal relatives. It is as though v2.0 OS Human is the beta version in anticipation of the debugged and improved v2.1.
Ignoring for a moment the flirt from v2.1 winking at us from the corner, the most salient phenotype of v2.0 compared to v1.7: OS Ape is certainly a profound manifestation of consciousness. While environmental manipulation and tool use can be found in other “lesser” species, humans are the only example of what I’ll call “existential validation,” which is our conscious ability to ponder the essence of our self-awareness. To be self-aware is one thing – something dolphins even exhibit – but to ponder the essence of self-awareness is something entirely more complex, if not uniquely human. Not-so-coincidentally, both psychosis and the faculty of language are thought to have contemporaneously arrived from a single genetic “big bang” event unique to the human species. Hence, it doesn’t require a giant leap for Apekind to posit that this event may be interdigitated with the other rapid genetic changes taking place some 6 million years ago as we upgraded from v1.7 OS Ape to v2.0 OS Human, albeit with some quirks (psychosis, neurodegeneration, etc.) in our new synaptic software.
And so what may come to define v2.1 OS Human? Unfortunately, the ability to understand v2.1 may violate Marty McFly’s time continuum paradox since understanding v2.1 may require exactly that: v2.1 – “Great Scott!”. I realize this is heavy, despite there being no problem with gravity in the future, but it’s no different than trying to illustrate a sphere to an entity that lives in two dimensions: three dimensions are required for a sphere to exist, without which only a circle exists and it’s a logic violation to illustrate a sphere in two dimensions. How then, stranded upon the islands of existential validation, language, and (non-family holiday) psychotic breakdowns, can humans persuade evolution to vote us off our v2.0 island in favor of v2.1? Perhaps we need to add another dimension.
While it is illogical for a 2-dimensional stick person to draw a sphere, it is not illogical for Stick Person (or “Stee-P” as they’re known in the hood) to ponder a sphere. In fact, humans ponder higher-order dimensions right here in v2.0, filling our cortex with the hubris of the 11-dimensional energetic vibrations of String Theory. Except for the tantalizing imagery that may project in most women, it is impossible to illustrate 11 vibrational dimensions in our cozy 4-dimensional realm (including time, thanks to that one German guy, among others). So what might the next dimension of v2.0 OS Human look like that will allow us access to the unchartered v2.1? Of course, no one knows – especially me. But we can certainly ponder.
Very little is understood about the functions of the Human Accelerated Region (HAR), but early indications point toward roles in cortical lamination (the ordered neuronal layers in the cortex of the brain; humans have six layers) and neuronal migration. This furthers the notion that while human synapses largely mirror that of the chimpanzee, it is the hardware by which those synapses align that give us the conscious advantage. The extended consequence of this unique alignment mandates our behavior since, among other extroversions, the functional output of the brain includes behavior no less than the functional output of the heart includes pumping blood and tattooing emo kids. And so if the HAR is dictating a uniquely human proteome that directs a uniquely human behavior, how then could any behavior we elicit usurp the dictation of a genetic mandate? In other words, how can our behavior, from our conscious creation of antibiotics and the internet to nuclear weapons and pollution, be any other than the prescription of our genes selected upon through our environment, which we paradoxically manipulate? If true, this apostasy threatens the intellect of free will into a biological dystopia of Genetic Big Brother. A caveat, however, is warranted here since in the collective sense – that is, the amalgamation of human conscious behavior (nuclear weapons, for instance, were not created by one conscious person) – would be behind the upper-dimensional steering wheel of v2.1, leaving our free-willed, individual behavior as an ignorant stochastic contributor. This is akin to Stee-P’s ignorant creation of a circle that may only be a 2-dimensional projection of a sphere in three dimensions – a dimension Stee-P doesn’t comprehend no matter the pedagogic savvy.
Alas, the seemingly dystopic Genetic Big Brother may actually have a utopic even-bigger sister where 2 + 2 really does = 5, albeit only from the perspective of v2.1 OS Human. The nature of human behavior, dictated collectively by our genes (and possibly the HAR) is an amalgamation of individual behaviors that seeks survival, not extinction. Therefore, perhaps the sum equation of human behavior can only perpetuate our existence. For example, global warming (or “Global Hotting” if you lived in the Pacific Northwest last summer) may actually be a genetically intended consequence of industrialization in that the stress global warming injects into the system incites new behaviors (i.e. technology) to resolve that stress, thereby advancing our species one step closer v2.1. Evolution as we know it is contingent on organismal stress, without which there would be no need for genetic modifications. The uniqueness of the evolutionary pressures on humans is that our consciousness is paradoxically manipulating the environment by which we are being stressed; it’s as though conscious thought in n-dimensions is acting through collective behaviors to evolve itself by perpetuating a constant stress in the system. And of course, we would be completely ignorant to this process since it would be operating from a foreign code, or “dimension,” that is uninterpretable to human consciousness as we know it in v2.0 OS Human. The human story is most certainly a unique story, no matter the language in which it is told. Our current genetic version is simply the most recent revision of a tale that has percolated the conscious lexicon for centuries, perhaps best framed by Rene Descartes with his “cogito ergo sum”. While the characters and settings in this story are often lucid and resolute, the plot is often cryptic and the finale remains unwritten. Or is it? Perhaps the language of the Creator (yes, that portly white guy with the beard), in all its infinite dimensional contortions, has concealed the plot and its finale much like concealing the nature of a sphere from Stee-P living on a 2-dimensional piece of paper. Humans could very well be just like Stee-P where an n-dimensional sphere passing through our 4-dimensional world is beyond our relegated v2.0 OS Human comprehension.
Or I could be wrong. Completely. The musings above may only serve the purpose to inject a stress, in this case into the reader, and cause everything I say to be consciously ignored in favor of species propagation. After all, a chimpanzee could have flexed its genetic wit to write 98% of this column. Ironically, it took the other 2% for me to realize this. And so it looks like I’ll be stuck with v2.0 for a while longer.
Selected References:
Crow, T.J. The "big bang" Theory of the origin of psychosis and the faculty of language. Schizophr Res 102(1-2):31-52 (2008).
Emes, R.D., Pocklington, A.J., Anderson, C.N.G., Bayes, A., Collins, M.O., et al. Evolutionary expansion and anatomical specialization of synapse proteome complexity. Nat Neurosci 11(7): 799-806 (2008).
Hill, R.S., Walsh, C.A. Molecular insights into human brain evolution. Nat Cell Biol 437(7055): 64-7 (2005).
Pollard, K.S., Salama, S.R., Lambert, N., Lambot, M., Coppins, S., Pederson, J.P., et al. An RNA gene expressed during cortical development evolved rapidly in humans. Nature 443(7108): 167-72 (2006).
Ryan, T.J., Grant, S.G.N. The origin and evolution of synapses. Nat Rev Neurosci 10(10): 701-12 (2009).
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