(05/20/2023) We assess the future of our evolutionary journey by asking what it was like, experientially, to be at the forefront of ancestral human cognition. We examine the role of choice in human evolutionary history, describing expression changes in synaptic genes of the prefrontal cortex as a key driver of our cognition, and see how such changes are driven by behavior, by our ancestors choosing to live at the limits of their cognitive abilities. We examine the embodied metaphors on which abstract thought is based, the original function of the brain region that was recruited for language, and the drawbacks to inhabiting a symbolic world. Does the experience of meditation parallel the greater self-control our ancestors found with an enlarging prefrontal cortex? Did the evolution of language involve a stage that was sort of pretentious and perhaps uncannily reminiscent of performance art? Were those who saw beyond the confines of ancestral human abilities treated as outsiders, as deviants so often are? Finally, what would it be like to live at the limits of our abilities, and thus promote further evolution, today? What limits would we seek to transgress? We offer a tentative answer in the abandonment of worldviews based on psychological need, in favor of simply seeing the world as it is, confronting any horrors that emerge along the way.
I tried annotating the bibliography this time. I'm aware it would often be difficult to discern a correspondence between the various statements made throughout the course of an episode and the citations. If this proves particularly helpful (or particularly a hindrance) please let me know.
Bibliography for episode 63:
Carroll, S. B. (2005) Endless Forms Most Beautiful: The New Science of Evo Devo. W. W. Norton.
The means by which variable gene expression occurs: histones, switches immediately upstream of coding sequences incorporating other gene products, etc.
Diamond A, Ling DS. (2016) Conclusions about interventions, programs, and approaches for improving executive functions that appear justified and those that, despite much hype, do not. Dev Cogn Neurosci. 18:34-48. doi: 10.1016/j.dcn.2015.11.005
The fundamental, interrelated functions of the prefrontal cortex: inhibitory control, working memory, and cognitive flexibility.
Draganski, B., Gaser, C., Busch, V. et al. Changes in grey matter induced by training. Nature 427, 311–312 (2004). https://doi.org/10.1038/427311a
Citing at random to illustrate how any experience of learning affects brain structure: the brain structure effects of juggling!
Gilbert, S. F. (2006) Developmental Biology. 8th edition. Sinauer Associates.
The means by which variable gene expression occurs.
Lakoff, G. & Johnson, M. (2003) Metaphors We Live By. University of Chicago Press.
Our discussion of the repurposing of embodied experience for the evolution of abstract thought.
Lorenz, K. (1950) Part and parcel in animal and human societies: A methodological discussion. In: Lorenz, K. (1971) Studies in Animal and Human Behavior vol. II. Harvard University Press.
This contains Lorenz's description of development as inherently perilous and humans as the species which retains, to an unparalleled degree, the behavioral plasticity of early development, still my favorite rendering of the neoteny hypothesis of human evolution.
Somel, M., Liu, X. & Khaitovich, P. Human brain evolution: transcripts, metabolites and their regulators. Nat Rev Neurosci 14, 112–127 (2013). https://doi.org/10.1038/nrn3372
This is the paper that describes neotenous changes, with respect to other primates, in the expression timing of genes involved in synapse production in the human prefrontal cortex. An excellent illustration of how gene expression changes, rather than sequence changes, often play a more fundamental role in driving evolution.
Stout D. (2011) Stone toolmaking and the evolution of human culture and cognition. Philos Trans R Soc Lond B Biol Sci. 366(1567):1050-9. doi: 10.1098/rstb.2010.0369
Presents a hierarchical action scheme for tool production, showing increasing number of steps and recursively embedded sub-routines in toolmaking throughout human evolution.
West Eberhard, M. J. (2003) Developmental Plasticity and Evolution. Oxford University Press. Good insights into gene expression vs. gene sequence differences specifically, but more generally thinking of evolution in far more broad terms than random gene sequence mutations. This is the closest thing to a sacred text Fight Like An Animal has.
Image by Autonomy Press