VI. Earth Life Emergence: Development of Body, Brain, Selves and Societies
1. The Evolution of Cerebral Form and Cognizance
Murray, Elizabeth, et al. The Evolution of Memory Systems. New York: Oxford University Press, 2017. The authors Elizabeth Murray (physiology and psychology) and Steven Wise (neurobiology) are at the National Institute of Mental Health, and Kim Graham is a cognitive neuroscientist at Cambridge University. They accomplish a 500 page treatise on how Earth life came to possess neural capacities to remember and retrieve so as to better survive, evolve and flourish. Five sections are Foundations of Memory systems, Architecture of Vertebrate Memory, Primate Augmentations, Hominin Adaptations, and Deconstructing and Reconstructing Memory Systems. One may add that as this homologous creaturely course reaches our sapient retrospective it quite appears as a long embryonic gestation.
Current theories about human memory have been shaped by clinical observations and animal experiments. This doctrine holds that the medial temporal lobe subserves one memory system for explicit or declarative memories, while the basal ganglia subserves a separate memory system for implicit or procedural memories, including habits. Cortical areas outside the medial temporal lobe are said to function in perception, motor control, attention, or other aspects of executive function, but not in memory. 'The Evolution of Memory Systems' proposes that several memory systems arose during evolution and that they did so for the same general reason: to transcend problems and exploit opportunities encountered by specific ancestors at particular times and places in the distant past. Instead of classifying cortical areas in terms of mutually exclusive perception, executive, or memory functions, the authors show that all cortical areas contribute to memory and that they do so in their own ways-using specialized neural representations.
Negyessy, Laszlo, et al. Convergence and Divergence are Mostly Reciprocated Properties of the Connections in the Network of Cortical Areas. Proceedings of the Royal Society B. 275/2403, 2008. A team of Hungarian neuroscientists report on a systemic complementarity which distinguishes these cortical phenomena, along with a hierarchical division of labor. These findings, if one may reflect, evince once more that a universal dynamics is instantiated in our brains and thought as everywhere else from galaxies to Gaia.
Ng, Renny, et al. Neuronal Compartmentalization: A Means to Integrate Sensory Input at the Earliest Stage of Information Processing. BioEssays. July, 2020. UC San Diego neurobiologists graphically demonstrate how life’s developmental propensity to form functional modules persists from initial rudiments across the span of invertebrate and mammalian species. From the get-go, neural operations are performed by bounded cellular whole units.
In peripheral sense organs, external stimuli are detected by sensory neurons compartmentalized within structures of cuticular or epithelial tissue. Beyond developmental constraints, such compartmentalization allows grouped neurons to functionally interact. Here, we review the prevalence of these units, describe compartmentalized neurons, and consider interactions between cells. Particular attention is paid to insect olfaction with well‐characterized mechanisms of functional, cross‐neuronal interactions. (Abstract excerpt)
Nomura, Tadashi, et al. Reptiles: A New Model for Brain Evo-Devo Research? Journal of Experimental Zoology B. Online January, 2013. Kyoto Prefectural University of Medicine, Ehime University, and National Institute of Neuroscience, Toyko, investigators contend that in the lineage of amniotic, egg laying or bearing, organisms, this ancient Reptilia Class can provide a revealing array of iconic forebears. Telencephalon, diencephalon, optic tectum, cerebellum, and medulla each appear in rudimentary forms. Lizard neurogenesis, for example, can be seen to presage avian and mammalian cerebral plans. Might one then ask, whom as if a similar, nascent global brain/mind is now proceeding altogether to reconstruct this? What kind of an abiding universe tries to learn and achieve, billions of years on, its own self-observation, witness, comprehension, so as to actively, decisively, select itself?
Vertebrate brains exhibit vast amounts of anatomical diversity. In particular, the elaborate and complex nervous system of amniotes is correlated with the size of their behavioral repertoire. However, the evolutionary mechanisms underlying species-specific brain morphogenesis remain elusive. In this review we introduce reptiles as a new model organism for understanding brain evolution. These animal groups inherited ancestral traits of brain architectures. We will describe several unique aspects of the reptilian nervous system with a special focus on the telencephalon, and discuss the genetic mechanisms underlying reptile-specific brain morphology. The establishment of experimental evo-devo approaches to studying reptiles will help to shed light on the origin of the amniote brains. (Abstract)
O’Connell, Lauren. Evolutionary Development of Neural Systems in Vertebrates and Beyond. Journal of Neurogenetics. 27/3, 2013. For this Harvard University, Center for Systems Biology, researcher such a comprehensive reconstruction of how creaturely neurological systems came to be and evolve is now possible. With a full scenario from urchins to us now in view, a consistent, ramifying image as an embryonic development becomes evident. The second quote notes its affinity to the popular “deep homology” model to inform this realization.
The emerging field of “neuro-evo-devo” is beginning to reveal how the molecular and neural substrates that underlie brain function are based on variations in evolutionarily ancient and conserved neurochemical and neural circuit themes. Comparative work across bilaterians is reviewed to highlight how early neural patterning specifies modularity of the embryonic brain, which lays a foundation on which manipulation of neurogenesis creates adjustments in brain size. Small variation within these developmental mechanisms contributes to the evolution of brain diversity. Comparing the specification and spatial distribution of neural phenotypes across bilaterians has also suggested some major brain evolution trends, although much more work on profiling neural connections with neurochemical specificity across a wide diversity of organisms is needed. These comparative approaches investigating the evolution of brain form and function hold great promise for facilitating a mechanistic understanding of how variation in brain morphology, neural phenotypes, and neural networks influences brain function and behavioral diversity across organisms. (Abstract)
O’Connell, Lauren and Hans Hofmann. Evolution of a Vertebrate Social Decision-Making Network. Science. 336/6085, 2012. University of Texas, Austin, neuroscientists offer further insights into a “remarkable conservation” of neural substrates for animal behaviors from life’s earliest multicellular appearance. For a further survey of Decision Theory views see Genes, Hormones, and Circuits by the authors in Frontiers in Neuroendocrinology (32/320, 2011), Evolutionary Themes in the Neurobiology of Social Cognition by Hofmann and Chelsea Weitekamp in Current Opinion in Neurobiology (28/1, 2014), Decision Making: The Neuroethological Turn by John Pearson, et al, in Neuron (82/5, 2014), and a special issue The Principles of Goal-Directed Decision-Making of the Philosophical Transactions of the Royal Society B (3699/1655, 2014).
Animals evaluate and respond to their social environment with adaptive decisions. Revealing the neural mechanisms of such decisions is a major goal in biology. We analyzed expression profiles for 10 neurochemical genes across 12 brain regions important for decision-making in 88 species representing five vertebrate lineages. We found that behaviorally relevant brain regions are remarkably conserved over 450 million years of evolution. We also find evidence that different brain regions have experienced different selection pressures, because spatial distribution of neuroendocrine ligands are more flexible than their receptors across vertebrates. Our analysis suggests that the diversity of social behavior in vertebrates can be explained, in part, by variations on a theme of conserved neural and gene expression networks. (O’Connell Abstract)
Phelps, Steven. Like Minds: Evolutionary Convergence in Nervous Systems. Trends in Ecology & Evolution. 17/4, 2002. A conference summary of how both somatic and mental development employ common solutions.
Pontes, Anselmo, et al. The Evolutionary Origin of Associative Learning. American Naturalist. 195/1, 2020. By way of clever digital simulations in Richard Lenski’s lab, Michigan State University researchers including Christoph Adami test whether this analogic edification, drawn much from Simona Ginsberg and Eva Jablonka (see definitions below), is actually in effect. Indeed, results over many generations show that life does become smarter by a constant, iterative, combinational process of trials, errors and successes for both entities and groups. From 2020, a central developmental trend of “stepwise, modular, complex behaviors” as an open-ended creativity is evidentially traced and oriented.
Learning is a widespread ability among animals and is subject to evolution. But how did learning first arise? What selection pressures and phenotypic preconditions fostered its evolution? Neither the fossil record nor phylogenetic comparative studies provide answers. Here, we study digital organisms in environments that promote the evolution of navigation and associative learning. Starting with a sessile ancestor, we evolve multiple populations in four environments, each with nutrient trails with various layouts. We find that behavior evolves modularly and in a predictable sequence. Environmental patterns that are stable across generations foster the evolution of reflexive behavior, while environmental patterns that vary across generations but remain consistent for periods within an organism’s lifetime foster the evolution of learning behavior. (Abstract excerpt)
Premack, David. Human and Animal Cognition. Proceedings of the National Academy of Sciences. 104/13861, 2007. The University of Pennsylvania primatologist argues that although an evolutionary continuity exists with our chimpanzee ancestors, human brains possess a greatly enhanced inter-connectivity. As a result, eight domains are cited that set us quite apart: teaching, short-term memory, causal reasoning, planning, deception, transitive inference, theory of mind, and language.
Reader, Simon and Kevin Laland. Social Intelligence, Innovation and Enhanced Brain Size in Primates. Procedings of the National Academy of Sciences. 99/4436, 2002. An extensive literature search on social learning, invention, and tool use reveals a close correlation between brain size and cognitive capacity.
Redies, Christoph and Luis Puelles. Modularity in Vertebrate Brain Development and Evolution. BioEssays. 23/12, 2001. Semi-autonomous, diverse modules are at work in both the embryonic and functional phases of cerebral formation. Here is another example of the constant modularity throughout the biological kingdom.
It is thought that modularity plays an important role in the evolutionary divergence of species, because modularity allows for adaptive modification of form and function of individual body parts while, at the same time, keeping the general developmental basic plan (Bauplan) of the organism the same. (1100)
Reid, Chris, et al. Information Integration and Multiattribute Decision Making in Non-neuronal Organisms. Animal Behavior. Vol. 100, 2015. As lately possible, Rutgers University and University of Sydney biologists advance the finding that even this most rudimentary phase of animal life and evolution is distinguished by the same individual and colonial behaviors as every other stage and kingdom. Circa 2015, a grand conclusion due to humankind altogether may accrue. Earthly biological and cognitive development does proceeds as a radiation and elaboration of a singular body, brain and societal Bauplan, which quite infers an embryonic gestation. See also Collective Sensing and Collective Responses in Quorum-Sensing Bacteria by Roman Popat in Journal of the Royal Society Interface (Vol.12/Iss.103, 2015) for a similar statement.
Decision making is a necessary process for most organisms, even for the majority of known life forms: those without a brain or neurons. The goal of this review is to highlight research dedicated to understanding complex decision making in non-neuronal organisms, and to suggest avenues for furthering this work. We review research demonstrating key aspects of complex decision making, in particular information integration and multiattribute decision making, in non-neuronal organisms when (1) utilizing adaptive search strategies when foraging, (2) choosing between resources and environmental conditions that have several contradictory attributes and necessitate a trade-off, and (3) incorporating social cues and environmental factors when living in a group or colony. We discuss potential similarities between decision making in non-neuronal organisms and other systems, such as insect colonies and the mammalian brain, and we suggest future avenues of research that use appropriate experimental design and that take advantage of emerging imaging technologies.