Cause of Cambrian Explosion - Terrestrial or Cosmic?

Ethics and Invertebrates: The Problem Is Us

In the last few decades, science has begun to make great strides at understanding how varied, fascinating, and intelligent invertebrate animals are. Because they are poorly known, the invertebrates that make up about 98% of the animals on the planet have been overlooked. Because they are seen as both simple and unattractive, children and their teachers, as well as the general public, do not think they need care. Because until recently we did not know they can be both intelligent and sensitive-bees can learn from each other, butterflies can navigate huge distances, octopuses are smart, and lobsters can feel pain-we have to give them the consideration they deserve. This collection of papers should help us to see how the lives of invertebrates are tightly linked to ours, how they live, and what they need in terms of our consideration and care.

Prebiotic chemistry: a review of nucleoside phosphorylation and polymerization

The phosphorylation of nucleosides and their polymerization are crucial issues concerning the origin of life. The question of how these plausible chemical processes took place in the prebiotic Earth is still perplexing, despite several studies that have attempted to explain these prebiotic processes. The purpose of this article is to review these chemical reactions with respect to chemical evolution in the primeval Earth. Meanwhile, from our perspective, the chiral properties and selection of biomolecules should be considered in the prebiotic chemical origin of life, which may contribute to further research in this field to some extent.

Viroids and the Origin of Life

Viroids are non-coding circular RNA molecules with rod-like or branched structures. They are often ribozymes, characterized by catalytic RNA. They can perform many basic functions of life and may have played a role in evolution since the beginning of life on Earth. They can cleave, join, replicate, and undergo Darwinian evolution. Furthermore, ribozymes are the essential elements for protein synthesis of cellular organisms as parts of ribosomes. Thus, they must have preceded DNA and proteins during evolution. Here, we discuss the current evidence for viroids or viroid-like RNAs as a likely origin of life on Earth. As such, they may also be considered as models for life on other planets or moons in the solar system as well as on exoplanets.

Cometary panspermia and origin of life?

A range of astronomical observations are shown to be in accord with the theory of cometary panspermia. This theory posits that comets harbor a viable biological component in the form of bacteria and viruses that led to origin and evolution of life on Earth. The data includes (1) infrared, visual and ultraviolet spectra of interstellar dust, (2) infrared spectra of the dust released from comet Halley in 1986, (3) infrared spectra of comet Hale-Bopp in 1997, (4) near and mid-infrared spectra of comet Tempel I in 2005, (5) the discovery of an amino acid and degradation products attributable to biology in the material recovered from the Stardust Mission in 2009, (6) jets from comet Lovejoy showing both a sugar and Ethyl alcohol and finally, (7) a diverse set of data that has emerged from the Rosetta mission. The conjunction of all the available data points to cometary biology and interstellar panspermia as being inevitable.

Introduction-Panspermia, 2020

This current volume is, in many ways, a 2020 update to the important 1999–2000 compendium by Sir Fred Hoyle and Professor N. Chandra Wickramasinghe's “Astronomical Origins of life: Steps towards Panspermia.” The emerging new paradigm of biology that connects life on Earth with the wider cosmos is covered in considerable depth showing that terrestrial biological evolution is best understood as a cosmically derived habitat and an interconnected genetic system. The various chapters here discuss all aspects of this interconnectedness, particularly relevant now in this time of the coronavirus pandemic (COVID-19) as the human race reacts to the many microbes and viral pathogens that arrive regularly from space.

Early evolutionary history (from bacteria to hemichordata) of the omnipresent purinergic signalling: A tribute to Geoff Burnstock inquisitive mind

Purines and pyrimidines are indispensable molecules of life; they are fundamental for genetic code and bioenergetics. From the very early evolution of life purines have acquired the meaning of damage-associated extracellular signaller and purinergic receptors emerged in unicellular organisms. Ancestral purinoceptors are P2X-like ionotropic ligand-gated cationic channels showing 20-40% of homology with vertebrate P2X receptors; genes encoding ancestral P2X receptors have been detected in Protozoa, Algae, Fungi and Sponges; they are also present in some invertebrates, but are absent from the genome of insects, nematodes, and higher plants. Plants nevertheless evolved a sophisticated and widespread purinergic signalling system relying on the idiosyncratic purinoceptor P2K1/DORN1 linked to intracellular Ca²⁺ signalling. The advance of metabotropic purinoceptors starts later in evolution with adenosine receptors preceding the emergence of P2Y nucleotide and P0 adenine receptors. In vertebrates and mammals the purinergic signalling system reaches the summit and operates throughout all tissues and systems without anatomical or functional segregation.

Gene Editing: A Tool for Tackling Cephalopod Biology

Cephalopods fascinate us but have been out of the reach of experimental manipulations at the genetic level. A new study describes editing of a gene in a squid using CRISPR.

The efficient Lamarckian spread of life in the cosmos

In this Chapter we discuss the various mechanisms that are available for the possible transfer of cosmic microbial living systems from one cosmic habitat to another. With the 100 or so habitable planets that are now known to exist in our galaxy alone transfers of cometary dust carrying life including fragments of icy planetoids/asteroids would be expected to occur on a routine basis. It is thus easy to view the galaxy as a single connected "biosphere" of which our planet Earth is a minor component. The Hoyle-Wickramasinghe Panspermia paradigm provides a cogent biological rationale for the actual widespread existence of Lamarckian modes of inheritance in terrestrial systems (which we review here). Thus the Panspermia paradigm provides the raison d'etre for Lamarckian Inheritance. Under a terrestrially confined neoDarwinian viewpoint such an association may have been thought spurious in the past. Our aim here is to outline the main evidence for rapid terrestrial-based Lamarckian-based evolutionary hypermutation processes dependent on reverse transcription-coupled mechanisms among others. Such rapid adaptation mechanisms would be consistent with the effective cosmic spread of living systems. For example, a viable, or cryo-preserved, living system traveling through space in a protective matrix will of necessity need to adapt rapidly and proliferate on landing in a new cosmic niche. Lamarckian mechanisms thus come to the fore and supersede the slow (blind and random) genetic processes expected under neoDarwinian Earth centred theories.

Origin of new emergent Coronavirus and Candida fungal diseases-Terrestrial or cosmic?

The origins and global spread of two recent, yet quite different, pandemic diseases is discussed and reviewed in depth: Candida auris, a eukaryotic fungal disease, and COVID-19 (SARS-CoV-2), a positive strand RNA viral respiratory disease. Both these diseases display highly distinctive patterns of sudden emergence and global spread, which are not easy to understand by conventional epidemiological analysis based on simple infection-driven human- to-human spread of an infectious disease (assumed to jump suddenly and thus genetically, from an animal reservoir). Both these enigmatic diseases make sense however under a Panspermia in-fall model and the evidence consistent with such a model is critically reviewed.

Percolation clusters of organics in interstellar ice grains as the incubators of life

Biomolecules can be synthesized in interstellar ice grains subject to UV radiation and cosmic rays. I show that on time scales of ≳10⁶ years, these processes lead to the formation of large percolation clusters of organic molecules. Some of these clusters would have ended up on proto-planets where large, loosely bound aggregates of clusters (superclusters) would have formed. The interior regions of such superclusters provided for chemical micro-environments that are filtered versions of the outside environment. I argue that models for abiogenesis are more likely to work when considered inside such micro-environments. As the supercluster breaks up, biochemical systems in such micro-environments gradually become subject to a less filtered environment, allowing them to get adapted to the more complex outside environment. A particular system originating from a particular location on some supercluster would have been the first to get adapted to the raw outside environment and survive there, thereby becoming the first microbe. A collision of a microbe-containing proto-planet with the Moon could have led to fragments veering off back into space, microbes in small fragments would have been able to survive a subsequent impact with the Earth.

Lamarck and Panspermia - On the Efficient Spread of Living Systems Throughout the Cosmos

We review the main lines of evidence (molecular, cellular and whole organism) published since the 1970s demonstrating Lamarckian Inheritance in animals, plants and microorganisms viz. the transgenerational inheritance of environmentally-induced acquired characteristics. The studies in animals demonstrate the genetic permeability of the soma-germline Weismann Barrier. The widespread nature of environmentally-directed inheritance phenomena reviewed here contradicts a key pillar of neo-Darwinism which affirms the rigidity of the Weismann Barrier. These developments suggest that neo-Darwinian evolutionary theory is in need of significant revision. We argue that Lamarckian inheritance strategies involving environmentally-induced rapid directional genetic adaptations make biological sense in the context of cosmic Panspermia allowing the efficient spread of living systems and genetic innovation throughout the Universe. The Hoyle-Wickramasinghe Panspermia paradigm also developed since the 1970s, unlike strictly geocentric neo-Darwinism provides a cogent biological rationale for the actual widespread existence of Lamarckian modes of inheritance - it provides its raison d'être. Under a terrestrially confined neo-Darwinian viewpoint such an association may have been thought spurious in the past. Our aim is to outline the conceptual links between rapid Lamarckian-based evolutionary hypermutation processes dependent on reverse transcription-coupled mechanisms among others and the effective cosmic spread of living systems. For example, a viable, or cryo-preserved, living system travelling through space in a protective matrix will need of necessity to rapidly adapt and proliferate on landing in a new cosmic niche. Lamarckian mechanisms thus come to the fore and supersede the slow (blind and random) genetic processes expected under a traditional neo-Darwinian evolutionary paradigm.

Viroids-First—A Model for Life on Earth, Mars and Exoplanets

The search for extraterrestrial life, recently fueled by the discovery of exoplanets, requires defined biosignatures. Current biomarkers include those of extremophilic organisms, typically archaea. Yet these cellular organisms are highly complex, which makes it unlikely that similar life forms evolved on other planets. Earlier forms of life on Earth may serve as better models for extraterrestrial life. On modern Earth, the simplest and most abundant biological entities are viroids and viruses that exert many properties of life, such as the abilities to replicate and undergo Darwinian evolution. Viroids have virus-like features, and are related to ribozymes, consisting solely of non-coding RNA, and may serve as more universal models for early life than do cellular life forms. Among the various proposed concepts, such as “proteins-first” or “metabolism-first”, we think that “viruses-first” can be specified to “viroids-first” as the most likely scenario for the emergence of life on Earth, and possibly elsewhere. With this article we intend to inspire the integration of virus research and the biosignatures of viroids and viruses into the search for extraterrestrial life.

Viruses and Evolution - Viruses First? A Personal Perspective

The discovery of exoplanets within putative habitable zones revolutionized astrobiology in recent years. It stimulated interest in the question about the origin of life and its evolution. Here, we discuss what the roles of viruses might have been at the beginning of life and during evolution. Viruses are the most abundant biological entities on Earth. They are present everywhere, in our surrounding, the oceans, the soil and in every living being. Retroviruses contributed to about half of our genomic sequences and to the evolution of the mammalian placenta. Contemporary viruses reflect evolution ranging from the RNA world to the DNA-protein world. How far back can we trace their contribution? Earliest replicating and evolving entities are the ribozymes or viroids fulfilling several criteria of life. RNA can perform many aspects of life and influences our gene expression until today. The simplest structures with non-protein-coding information may represent models of life built on structural, not genetic information. Viruses today are obligatory parasites depending on host cells. Examples of how an independent lifestyle might have been lost include mitochondria, chloroplasts, Rickettsia and others, which used to be autonomous bacteria and became intracellular parasites or endosymbionts, thereby losing most of their genes. Even in vitro the loss of genes can be recapitulated all the way from coding to non-coding RNA. Furthermore, the giant viruses may indicate that there is no sharp border between living and non-living entities but an evolutionary continuum. Here, it is discussed how viruses can lose and gain genes, and that they are essential drivers of evolution. This discussion may stimulate the thinking about viruses as early possible forms of life. Apart from our view “viruses first”, there are others such as “proteins first” and “metabolism first.”

The Current State of Cephalopod Science and Perspectives on the Most Critical Challenges Ahead From Three Early-Career Researchers

Here, three researchers who have recently embarked on careers in cephalopod biology discuss the current state of the field and offer their hopes for the future. Seven major topics are explored: genetics, aquaculture, climate change, welfare, behavior, cognition, and neurobiology. Recent developments in each of these fields are reviewed and the potential of emerging technologies to address specific gaps in knowledge about cephalopods are discussed. Throughout, the authors highlight specific challenges that merit particular focus in the near-term. This review and prospectus is also intended to suggest some concrete near-term goals to cephalopod researchers and inspire those working outside the field to consider the revelatory potential of these remarkable creatures.