VI. Earth Life Emergence: Development of Body, Brain, Selves and Societies
1. The Evolution of Cerebral Form and Cognizance
van Duijn, Marc. Phylogenetic Origins of Biological Cognition: Convergent Patterns in the Early Evolution of Learning. Interface Focus. 7/3, 2017. The University of Groningen paleoneurologist continues his reconstructive studies of how life gained sensory, information-based, cumulative abilities so as to survive and thrive. See also Principles of Minimal Cognition by van Duijin, et al in Adaptive Behavior (14/2, 2006) for a much cited prior entry, and Slime Moulds, Behavioural Ecology and Minimal Cognition by Jules Smith-Ferguson and Madeleine Beekman in Adaptive Behavior (January 2019). These findings and many others are filling in a embryonic gestation of cerebral capacities from life’s earliest advent to our collective abilities to learn all this.
Various forms of elementary learning have recently been discovered in organisms lacking a nervous system, such as protists, fungi and plants. This finding has fundamental implications for how we view the role of convergent evolution in biological cognition. In this article, I first review the evidence for basic forms of learning in aneural organisms, focusing particularly on habituation and classical conditioning. Next, I examine the possible role of convergent evolution regarding these basic learning abilities during the early evolution of nervous systems. This sets the stage for at least two major events relevant to convergent evolution that are central to biological cognition: (i) nervous systems evolved, perhaps more than once, because of strong selection pressures for sustaining sensorimotor strategies in increasingly larger multicellular organisms and (ii) associative learning was a subsequent adaptation that evolved multiple times within the neuralia. (Abstract excerpt)
Vincent, Jean-Didier and Pierre-Marie Lledo. The Custom-Made Brain: Cerebral Plasticity, Regeneration, and Enhancement. New York: Columbia University Press, 2014. Veteran French neuroscientists survey the billion year course of how neural anatomies and cognitions came to form, evolve, ramify, think, and learn on their way to knowing sentience in our retrospective human phase. We cite because in a section named Behind Diversity in the Animal Kingdom, a Single Plan the work describes how life’s evolutionary developmental encephalization of cerebral bilateral topology and thought is again much like an embryonic gestation.
Vitiello, Giuseppe. The Use of Many-body Physics and Thermodynamics to Describe the Dynamics of Rhythmic Generators in Sensory Cortices Engaged in Memory and Learning. Current Opinion in Neurobiology. 31/1, 2015. In a special issue on Brain Rhythms and Dynamic Coordination edited by Gyorgy Buzsaki and Walter Freeman, a University of Salerno physicist (search), often a collaborator with WF, advises that if neural faculties are seen as continuous with and arising from such natural depths, this can facilitate their full understanding.
The problem of the transition from the molecular and cellular level to the macroscopic level of observed assemblies of myriads of neurons is the subject addressed in this report. The great amount of detailed information available at molecular and cellular level seems not sufficient to account for the high effectiveness and reliability observed in the brain macroscopic functioning. It is suggested that the dissipative many-body model and thermodynamics might offer the dynamical frame underlying the rich phenomenology observed at microscopic and macroscopic level and help in the understanding on how to fill the gap between the bio-molecular and cellular level and the one of brain macroscopic functioning. (Abstract)
Williams, Caroline. A Beautiful Mind. New Scientist. June 11, 2011. A science writer lauds this heretofore daunting quantification of the neural regimen and cognitive acumen of the cephalopod octopus, which can be seen as a primordial instance of how brain and intelligence began their evolutionary ascent.
Yopak, Kara, et al. A Conserved Pattern of Brain Scaling from Sharks to Primates. Proceedings of the National Academy of Sciences. 107/12946, 2010. A team of neuroscientists from Australia, Sweden, and the United States, including Barbara Finlay and Richard Darlington, report remarkable cerebral similarities between such widely separate Metazoan species. Once again it can be increasingly surmised that evolution retains the same basic neural anatomy, which then ramifies and deploys by an interplay of concerted and mosaic size and capacity as emergent encephalization proceeds to our retrospective description.
Several patterns of brain allometry previously observed in mammals have been found to hold for sharks and related taxa (chondrichthyans) as well. In each clade, the relative size of brain parts, with the notable exception of the olfactory bulbs, is highly predictable from the total brain size. Compared with total brain mass, each part scales with a characteristic slope, which is highest for the telencephalon and cerebellum. In addition, cerebellar foliation reflects both absolute and relative cerebellar size, in a manner analogous to mammalian cortical gyrification. This conserved pattern of brain scaling suggests that the fundamental brain plan that evolved in early vertebrates permits appropriate scaling in response to a range of factors, including phylogeny and ecology, where neural mass may be added and subtracted without compromising basic function. (12946)
Yoshida, M., et al. Molecular Evidence for Convergence and Parallelism in Evolution of Complex Brains of Cephalopod Molluscs: Insights from Visual Systems. Integrative & Comparative Biology. 55/6, 2015. In a Dawn of Neuronal Organization section, a team from research institutes in Japan and Florida including Leonid Moroz (search) find these quite intelligent invertebrates to have an equivalent cerebral capacity to vertebrates. Once again, such 2010s worldwide findings affirm a persistence for life to form and elaborate similar neural architectures as an inherent evolutionary encephalization.
Coleoid cephalopods show remarkable evolutionary convergence with vertebrates in their neural organization, including (1) eyes and visual system with optic lobes, (2) specialized parts of the brain controlling learning and memory, such as vertical lobes, and (3) unique vasculature supporting such complexity of the central nervous system. We performed deep sequencing of eye transcriptomes of pygmy squids (Idiosepius paradoxus) and chambered nautiluses (Nautilus pompilius) to decipher the molecular basis of convergent evolution in cephalopods. RNA-seq was complemented by in situ hybridization to localize the expression of selected genes. We found three types of genomic innovations in the evolution of complex brains: (1) recruitment of novel genes into morphogenetic pathways, (2) recombination of various coding and regulatory regions of different genes, often called “evolutionary tinkering” or “co-option”, and (3) duplication and divergence of genes. In summary, the cephalopod convergent morphological evolution of the camera eyes was driven by a mosaic of all types of gene recruitments. In addition, our analysis revealed unexpected variations of squids’ opsins, retinochromes, and arrestins, providing more detailed information, valuable for further research on intra-ocular and extra-ocular photoreception of the cephalopods. (Abstract)