VI. Earth Life Emergence: Development of Body, Brain, Selves and Societies
5. Multicellular Fauna and Flora Organisms
Fisher, R. M., et al. The Evolution of Multicellular Complexity: The Role of Relatedness and Environmental Constraints. Proceedings of the Royal Society B. July, 2020. University of Copenhagen bioecologists including J. J. Boomsma provide further natural properties that impelled unicell organisms to join into beneficial groupings. Their prevalence then seen to imply how often this imperative (obligate) major transition has occurred.
A major challenge in evolutionary biology has been to explain variations in multicellularity across independently evolved lineages from slime moulds to vertebrates. Social evolution theory highlights relatedness in vitally complex forms. However, there is a need to extend this perspective to relative environments. In this paper, we test (John) Bonner's 1998 hypothesis that such settings are crucial to its course, with aggregative multicellularity evolving more frequently on land and clonal multicellularity more often in water. Using a combination of scaling theory and phylogenetic comparations, we describe complex organizations across 139 species spanning 14 independent transitions to multicellularity. Our results show that physical environments impact how multicellular groups form, and thus affect the major evolutionary transition to obligate multicellularity. (Abstract)
Fisher, Roberta, et al. Group Formation, Relatedness, and the Evolution of Multicellularity. Current Biology. Online June, 2013. As the Abstract details, Roberta Fisher and Stuart West, Oxford University zoologists, and biologist Charlie Cornwallis, Lund University, Sweden, propose that if life’s propensity to form into more complex entities via wholes within wholes is set within the major transitions scale an even better understanding of how and why this happens can be gained. It is worth noticing that while this ascension is good for individuality, a sense of and referral to a causal, formative source remains elusive. So this scenario is still seen as confirmation of how natural selection acts alone.
The evolution of multicellular organisms represents one of approximately eight major evolutionary transitions that have occurred on earth. The major challenge raised by this transition is to explain why single cells should join together and become mutually dependent, in a way that leads to a more complex multicellular life form that can only replicate as a whole. It has been argued that a high genetic relatedness (r) between cells played a pivotal role in the evolutionary transition from single-celled to multicellular organisms, because it leads to reduced conflict and an alignment of interests between cells. We tested this hypothesis with a comparative study, comparing the form of multicellularity in species where groups are clonal (r = 1) to species where groups are potentially nonclonal (r ≤ 1). We found that species with clonal group formation were more likely to have undergone the major evolutionary transition to obligate multicellularity and had more cell types, a higher likelihood of sterile cells, and a trend toward higher numbers of cells in a group. More generally, our results unify the role of group formation and genetic relatedness across multiple evolutionary transitions and provide an unmistakable footprint of how natural selection has shaped the evolution of life. (Abstract)
Furusawa, Chikara and Kunihiko Kaneko. Complex Organization in Multicellularity as a Necessity in Evolution. Mark Bedau, et al, eds. Artificial Life VII. Cambridge: MIT Press,, 2001. Another theoretical contribution to intimations of a inherent evolutionary tendency toward nested levels of cellular integration.
By introducing a dynamical system model of a multicellular system, it is shown that an organism with a variety of differentiated cell types and a complex pattern emerges through cell-cell interactions even without postulating any elaborate control mechanism. Such organism is found to maintain a larger growth speed as an ensemble by achieving a cooperative use of resources than simple homogeneous cells which behave ‘selfishly.’ This suggests that the emergence of multicellular organisms with complex organization is a necessity in evolution. (103)
Galvao, Viviane, et al. Modularity Map of the Network of Human Cell Differentiation. Proceedings of the National Academy of Sciences. 107/5750, 2010. A report from researchers in Brazil, Switzerland, and CCNY as a good example of scientific progress advancing beyond its reductive phase to novel recognitions of systemwide patterns and processes, as noted by its Abstract.
Cell differentiation in multicellular organisms is a complex process whose mechanism can be understood by a reductionist approach, in which the individual processes that control the generation of different cell types are identified. Alternatively, a large-scale approach in search of different organizational features of the growth stages promises to reveal its modular global structure with the goal of discovering previously unknown relations between cell types. Here, we sort and analyze a large set of scattered data to construct the network of human cell differentiation (NHCD) based on cell types (nodes) and differentiation steps (links) from the fertilized egg to a developed human.
Gilbert, Scott and Jessica Bolker. Homologies of Process and Modular Elements of Embryonic Construction. Journal of Experimental Zoology. 291/1, 2001. A Bauplan (archetypal body form) is invoked along with common dynamical systems which employ semi-autonomous modules for their processes of organic development.
Gosak, Marko, et al. Networks Behind the Morphology and Structural Design of Living Systems. Physics of Life Reviews. March, 2022. As a good example of timely abilities to achieve a convergent synthesis of nonlinear, animate complexities, five University of Maribor, Slovenia theorists including Matjaz Perc post a 40 page, 250 reference article with regard to life’s ubiquitous connectivities across every anatomic and physiological instance. For example intercellular and multicellular interaction patterns, fluid flows, neural nets and all else can be seen to exhibit similar topological dynamics. Today collaborative teams in every land, on a daily basis, altogether compose a speciesphere scientific endeavor going on by itself. But with insane carnage not far away, such a learning, thinking Earthuman faculty whom is achieving these revolutionary findings is still unknown. For such reasons, the evident presence of an independent, universal mathematic source in manifest effect still cannot be implied.
Advances in imaging techniques and biometric data methods have enabled us to apply the topological network properties to organelles, organs, and tissues, as well as the coordinations among them that yield a healthy, whole organism. We review research dedicated to these advances with a focus on networks between cells, the topology of multicellular structures, neural interactions, fluid transportation, and anatomies. The percolation of blood vessels, brain geometries, bone porosity, and relations between various parts of the human body are some examples we explore in detail. (Abstract excerpt))
Grossnickle, David, et al. Untangling the Multiple Ecological Radiations of Early Mammals. Trends in Ecology and Evolution. Online June, 2019. DG and Gregory Wilson, University of Washington along with Stephanie Smith, Field Museum of Natural History, Chicago, provide an extensive illustrated survey of our latest collective reconstruction of how life’s myriad creaturely species evolved and emerged. We muse and wonder whatever phenomenal contribution are we homo to Anthropo sapiens here by achieving for a self-revealing and auto-creating ecosmos.
The ecological diversification of early mammals is a globally transformative event in Earth’s history, largely due to the Cretaceous Terrestrial Revolution mass extinction. A confounding issue is that it comprised nested radiations of mammalian subclades within the broader scope of their evolution. In the past 200 million years, various independent groups experienced large-scale radiations involving ecological diversification from ancestral lineages of small insectivores such as include Jurassic mammalia forms, Late Cretaceous metatherians, and Cenozoic placentals. Here, we review these speciations which reveal the nuanced complexity of early mammal evolution, the value of ecomorphological fossil data, and phylogenetic context in macroevolutionary studies. (Abstract)
Halatek, Jacob, et al. Self-Organization Principles of Intracellular Pattern Formation. Philosophical Transactions of the Royal Society B. Vol.373/Iss.1747, 2018. In a technical paper, Ludwig Maximilian University, Munich biophysicists including Erwin Frey contribute to 21st century verifications of the presence, as long intimated (second quote), of nature’s propensity to form nested viable units of many members within reciprocal wholes. Circa 2018 this innate form and function can be quantified in detailed fashion by way of autocatalytic conversions via activator-inhibitor dynamics. See also Rethinking Pattern Formation in Reaction-Diffusion Systems by Halatek and Frey in Nature Physics (February 2018) and MinE Conformational Switching Confers Robustness on Self-Organized Min Protein Patterns in PNAS (115/4553, 2018). We note that since this multi-cellular section was posted in 2004 the presence of innate self-organized biological processes has moved from a remote idea to these theoretical confirmations.
Dynamic patterning of specific proteins is essential for the spatio-temporal regulation of many important intracellular processes in prokaryotes, eukaryotes and multicellular organisms. In this article, we review quantitative models for intracellular Min protein patterns in Escherichia coli, Cdc42 polarization in Saccharomyces cerevisiae and the bipolar PAR protein patterns found in Caenorhabditis elegans. By analysing the molecular processes driving these systems we derive general principles underlying self-organized pattern formation. Mass-conserving reaction–diffusion equations provide the most appropriate framework to study intracellular pattern formation. We conclude that directed transport, e.g. cytosolic diffusion along an actively maintained cytosolic gradient, is the key process underlying pattern formation. Thus the basic principle of self-organization is the establishment and maintenance of directed transport by intracellular protein dynamics. (Abstract excerpt)
Hammerschmidt, Katrin, et al. Life Cycles, Fitness Decoupling and the Evolution of Multicellularity. Nature. 515/75, 2014. Massey University, Auckland, and University of Washington, Seattle, researchers including Paul Rainey continue to quantify and explain how relative unicellular stages proceed to merge into organism forms of benefit both to member and the new individual. By so doing it is said that Darwinian selection processes shift by way of collective reproduction to this higher level. The surmise is a natural persistence for life to combine into whole nested entities by a ratcheted repetition.
Cooperation is central to the emergence of multicellular life; however, the means by which the earliest collectives (groups of cells) maintained integrity in the face of destructive cheating types is unclear. One idea posits cheats as a primitive germ line in a life cycle that facilitates collective reproduction. Here we describe an experiment in which simple cooperating lineages of bacteria were propagated under a selective regime that rewarded collective-level persistence. Collectives reproduced via life cycles that either embraced, or purged, cheating types. When embraced, the life cycle alternated between phenotypic states. Selection fostered inception of a developmental switch that underpinned the emergence of collectives whose fitness, during the course of evolution, became decoupled from the fitness of constituent cells. Our findings capture key events in the evolution of Darwinian individuality during the transition from single cells to multicellularity. (Abstract)
Herron, Matthew, et al. Genetics of a de Novo Origin of Undifferentiated Multicellularity. Royal Society Open Science. August, 2018. Georgia Tech biologists Herron, William Ratcliff, Jacob Boswell and Frank Rosenzweig post one more quantification of how inevitable and insistent life’s evolutionary emergence from single eukaryote cells to complex organisms seems to be. And this scalar step may be the most significant advance, since all subsequent organisms including us followed from its occasion.
The evolution of multicellularity was a major transition in evolution and set the stage for unprecedented increases in complexity, especially in land plants and animals. Here, we explore the genetics underlying a de novo origin of multicellularity in a microbial evolution experiment carried out on the green alga Chlamydomonas reinhardtii. We show that large-scale changes in gene expression underlie the transition to a multicellular life cycle. These results suggest that the genetic basis for the experimental evolution of multicellularity in C. reinhardtii has both lineage-specific and shared features, and that the shared features have more in common with C. reinhardtii's relatives among the volvocine algae than with other multicellular green algae or land plants. (Abstract)
Hiebert, Laurel, et al. Coloniality, Clonality, and Modularity in Animals. Journal of Experimental Zoology B. April, 2021. In this special issue, University of Sao Paulo, University of Colorado, and Sorbonne University biologists describe how the pervasive presence of these cooperative tendencies across diverse invertebrates achieve a beneficial recurrence of common, viable principles.
Nearly half of the animal phyla contain species that propagate asexually via agametic reproduction, often forming colonies of genetically identical modules, that is, ramets, zooids, or polyps. Clonal reproduction, colony formation, and modular organization have important consequences for many aspects of organismal biology. In this review, we present an overview of the study of colonial and clonal animals, from the historic interests in this subject to modern research in a range of topics, including immunology, stem cell biology, aging, biogeography, and ecology. (Abstract)
Hiebert, Laurel, et al. From the Individual to the Colony: Marine Invertebrates as Models to Understand Levels of Biological Organization. Journal of Experimental Zoology B. April, 2021. An introduction to a special Evolution of Animal Coloniality and Modularity issue of papers, as the abstract says, from a two week tutorial on these vital qualities of communal creatures. The eight research biologist authors including Carl Simpson and Federico Brown cite postings in Brazil, France, and the USA. See also herein Coloniality, Clonality, and Modularity in Animals (below) and Dynamical Patterning Modules and Network Motifs as Joint Determinants of Development.
The developmental and evolutionary principles of coloniality in marine animals remains a largely unexplored area. In late 2018, the inaugural course on the Evolution of Coloniality and Modularity took place at the Center for Marine Biology of the University of São Paulo. Its subject matter discussed past hypotheses and ways to test these using extant and paleontological data, along with observations of animal colonies in the different colonial phyla. Topics related to multi‐level selection, modular miniaturization, polymorphism, brooding, allorecognition and more were covered. (Course abstract)