On the early evolutionary stage of the geosphere and biosphere and the problem of early glaciations

The early evolutionary stages of the geosphere and biosphere are determined by three interrelated factors: (1) continuous cooling of the surface and interior (mantle) of the Earth (the mean temperatures of the mantle and surface decreased by a factor of 1.5–2 and 3–4, respectively; the mean heat flow was reduced by approximately one order of magnitude, and viscosity, by three orders); (2) continuous stepwise oxidation of the surface, which was particularly well pronounced from 3.8 to 1.8 Ga; and (3) periodic and correlated fluctuations of conditions in the geosphere and biosphere of varying extent and nature. The major boundaries of this evolution were about 4 Ga (the origin of rather thick and heterogeneous earth’s crust, the origin of life); about 3 Ga (appearance of a strong magnetic field, an increase in photosynthetic activity); about 1.8–1.9 Ga (appearance of an oxidized atmosphere, the first supercontinent, possibly, the first superplumes from the nucleus); and about 0.75 Ga (acceleration of subduction, “watering” of the upper mantle, elevation of continents with vast land masses, shelves, large rivers, and the first great glaciations). The significance and correlations of the earliest events (before and about 4 Ga) and events about 750 Ma are widely debated. In the Late Archean and Early Proterozoic (before 1.8 Ga), the biosphere was dominated by cyanobacteria, the dynamics and developmental peaks of which are marked by the presence of widespread stromatolite buildups in carbonaceous rocks (initially, mostly dolomitic matter). About 700–750 Ma, intense and frequent glaciations developed, marking the cooling of the Earth. The greatest glaciation apparently occurred about 640 Ma, which gave rise to the discussion of the model of the Snowball Earth. The emergence and evolution of skeletons in animals is sometimes thought to be connected with glaciations. These events are correlated and accounted for by great endogenous changes. One of the major events in endogenous history is the onset about 750 Ma of periodic manifestation of mantle flows (superplumes), which explain further periodicity of the biosphere evolution. In conclusion, extrapolation of future evolution and successive collapse of biosphere segments in the course of transformation of the Sun into a red star and warming of the Earth surface are proposed.     

EVOLUTION OR REVOLUTION OF AMMONOIDS AT MESOZOIC SYSTEM BOUNDARIES

1. Biological revolutions at major stratigraphical boundaries have been given numerous explanations involving endogenous biological, exogenous ecological, physical, and cosmic, as well as sedimentary or chemical factors. In an attempt to elucidate the true nature of these faunal revolutions and to assess the possible influence of biological and/or physical factors, the evolution of ammonites at the boundaries of Mesozoic stratigraphical Systems is reviewed. It is believed that the more detailed data now available can give a clearer impression of evolutionary events at these boundaries. 2. It can be demonstrated that there is neither an abrupt and world-wide extinction, nor a spontaneous replacement by new elements at these caesuras as had been generally supposed to have occurred at the Triassic-Jurassic boundary, for example. Instead, one can recognize three distinct phases in the sequence of events: (1) a continuous disappearance of the ‘antique’ faunal elements; (2) a similarly continuous, gradual, and largely synchronous appearance of, or substitution by, qualitatively distinguishable ‘modern’ elements in small populations, yet in various parallel lineages (mosaic evolution); (3) a quite revolutionary, and quantitatively very sudden, diversification of these new elements, occurring at or with some delay above the boundary. 3. Thus one can demonstrate both continuous evolution of the modern faunas (‘preadaptational phase’), as well as ‘discontinuous’ spontaneous revolution, which does not produce qualitatively new characters and must be explained by diversification or adaptive radiation. This means that no further explanation by internal factors or by higher mutation rates resulting from the impact of cosmic rays becomes necessary. It is believed that, preceded by high extinction rates, world-wide ecological factors promoting higher niche diversity suffice to explain these adaptive radiations. The high degree of provincialism, endemism and specialization of the ‘antique’ faunas and the constant survival of smooth oxycones — regarded as inhabitants of a deep-sea environment — demonstrate that marine regressions and transgressions were the most effective ecological factors. 4. If there is not too much time involved between the two events, the caesura (Faunenschnitt) between final extinction of the old faunas and the radiation of the new is the most appropriate point by which to define System boundaries.     

Probability of life. Rareness of realization in evolution

In order to have a general idea of evolution in biosphere, a multidimensional lattice space for genomes is proposed. A single point in the space corresponds to a genome, and it will leave branched trace in time in the space as evolution progress. When the trace is projected on a surface vertical to time axis, it occupies about 10¹² lattice points. This is a small fraction of the total number of lattice points, 10⁴⁰, which has been ever tried by the meandering genome point.     

Biostratigraphy or biochronology? Lessons from the Early and Middle Miocene small Mammal Events in Europe

Since the proposition in 1975 of the European Neogene Mammal (MN) scale by Pierre Mein, the amount of taxonomical, stratigraphical and chronological information around Europe has increased exponentially. In this paper, the stratigraphical schemes of three of the best studied areas for the Lower and Middle Miocene, the Aragonian type area in Spain and the Upper Freshwater Molasse from the North Alpine Foreland Basin in Switzerland and Bavaria, are compared. The correlation of their local biostratigraphies are discussed. Sixteen rodent's events are studied and ranked in the three areas according to their local biostratigraphy. This study shows, and quantifies for the first time, the significant asynchronies of the different included rodent events. The MN-system is discussed in the light of those results. In accordance, we propose that it is still useful but only in a biochronological way, as a sequence of time-ordered reference localities allowing coarse long-distance correlations. In order to obtain better temporal resolution, this system has to be combined with local biostratigraphies that are well calibrated to the time scale, implementing the information about synchrony and diachrony of mammal events in different areas.     

Causal biostratigraphy

Causal biostratigraphy means an approach to stratigraphic problems based on ecosystem analysis of interrelations between geological events and organic evolution. Thc succession of ecosystems is controlled mainly by climatic cycles. Stratigraphic units correspond to palececosystems. The units of higher ranks which are defined by changes of major biomes correspond to paleobiospheres. Their boundaries are designated by replacement of dominant types within the stratoecotones. Reconstruction of catenae, analysis of vicarious catenae systems, and correlation by cliserer are among the most useful methods of causal biostratigraphy.     

Misconceptions about parsimony analysis of endemicity

Parsimony analysis of endemicity (PAE) has been widely criticized in the recent literature based on methodology rather than on theory. Here I argue that most of the criticisms of PAE result from confusion between the dynamic and static approaches of PAE, by both users and critics of the method. Originally, PAE (the dynamic approach) was proposed primarily for historical comparisons of biotic distributions based on geological and stratigraphical information; that is, the stratigraphical record of the biota within two or more horizons was used to evaluate changes (layer by layer) in their distributional patterns. This led to an analysis of the biota throughout space and through time. On the other hand, the static approach excluded the temporal component and based the analysis on a single geological horizon. Most problems exemplified and discussed in the literature refer to the static approach. In addition to this defence of the original PAE, I present some new criticisms regarding the application of PAE using artificially delimited areas (for example areas defined by geopolitical boundaries), which may lead to incorrect interpretations. Recently, several variations of static PAE have appeared: some designed to accommodate ecological data (e.g. parsimony analysis of distributions – PAD); others that incorporate phylogenetic content (e.g. cladistic analysis of distributions and endemism – CADE); and some that have been integrated with other historical methods (e.g. panbiogeography) in order to detect and evaluate hypotheses of biogeographical homologies. Biogeographers, both ecological and historical, should be aware of the problems and limitations of both dynamic and static PAE and evaluate new variations of PAE (PAD, CADE, etc.). Finally, I argue in favour of an independent and pluralist discipline of biogeography that treats biogeography as related to systematics but not dependent on it, as some scholars have assumed.     

Natural background radiation: problem of radionuclide migration and biological effects

Natural radiation background is the main contributor to radiation dose delivered to plants, animals, and man. That is why its effects are of increasing interest in radiobiology, radioecology, and radiation hygiene. The following problems are discussed: migration of main natural radionuclides in biosphere, dose formation, biological role of natural radiation background on the Earth, standards for natural radiation background, and problems of natural radiation background and biosphere evolution. The tasks of further radiobiological research in evaluating the role of natural radiation background are outlined.     

Crucial crises in biology: life in the deep biosphere.

The origin and evolution of life on Earth are the result of a series of crises that have taken place on the planet over about 4500 millions of years since it originated. Biopoiesis (origin of life), ecopoiesis (origin of ecosystems) and the first ecosystems (stromatolites and microbial mats), as well as eukaryopoiesis (origin of nucleated cells) are revised. The paper then focuses on the study of the deep biosphere, describing ecosystems never found before, which are independent of solar radiation and have changed previous assumptions about the requirements of life; even the concept of biosphere, as Vernadsky defined it, has increased its scope. Since the discovery, in 1987, of bacteria growing in the crevices of rocks at 500 m deep, in boreholes drilled near the Savanna River, Aiken, South Carolina, other bacteria have been found in the deep subsurface reaching depths of about 3 km (e.g., in the Columbia River Basalt Group, near Richland, Washington state), in an anaerobic, hot, high-pressure environment. Some kinds of microorganisms can thrive at such depths, living in many cases a geochemical existence, by using very specialized metabolisms, which depend on the local environments. The existence of organisms independent from photosynthetic production is the most outstanding, novel feature of the deep biosphere. Living beings might not need other energy and chemical sources than those which occur in the development of all planetary bodies. Life, therefore, could even be an ineluctable outcome of planetary evolution and, as a corollary, a natural continuation of the usual development of physical phenomena in the universe.     

On the early stages of the evolution of the geosphere and biosphere

The conditions necessary for the existence of nucleic-protein life are as follows: the presence of liquid water, an atmosphere, and a magnetic field (all of which protect from meteorites, abrupt changes in temperature, and a flow of charged particles from space) and the availability of nutrients (macro-and microelements in the form of dissolved compounds). In the evolution of the geosphere, complex interference of irreversible processes (general cooling, gravitational differentiation of the Earth’s interior, dissipation of hydrogen, etc.) with cyclic processes of varying natures and periodicities (from the endogenic cycles “from Pangea to Pangea” to Milankovitch cycles), these conditions have repeatedly changed; hence, in the coevolution of the geosphere and biosphere, the vector of irreversible evolution was determined by the geosphere. Only with the appearance of the ocean as a global system of homeostasis, which provided the maintenance and leveling of nutrient concentrations in the hydrosphere, and the conveyor of nutrients from the mantle, “the film of life” could begin its expansion from the source of the nutrients. Life itself is a system of homeostasis, but not due to the global size and a vast buffer capacity, but because of the high rate of reactions and presence of a program (genome) that allowed its development (ontogeny) independent from the outside environment. The early stages of the origin and evolution of the biosphere (from the RNA-world to the development of the prokaryotic ecosystems) were characterized by the domination of chemotrophic ecosystems. The geographical ranges of these ecosystems were directly or indirectly (through the atmosphere and hydrosphere) tied to the sources of nutrients in the geosphere, which were in turn connected to various sources of volcanic and geotectonic activity (geothermal waters, “black smokers” along the rift zones, etc.). This gave the biosphere consisting of chemotrophic ecosystems a mosaic appearance composed of separate local oases of life. The decrease of methane and accumulation of O₂ in the atmosphere in the geological evolution of the Earth caused the extinction of chemotrophic ecosystems and directed evolution of the biosphere toward autotrophy. Autotrophic photosynthesis gave the biosphere an energy source that was not connected to the geosphere, and for the first time allowed its liberation from the geosphere by developing its own vector of evolution. This vector resulted in the biosphere forming a continuous film of life on the planet by capturing the continents and occupying pelagic and abyssal zones, and the appearance of eukaryotes. The geosphere formed biogeochemical cycles in parallel to the geochemical ones, and comparable in the annual balances of participating matter.     

Chemical Evolution and Meteorites: An Update

Carbonaceous chondrites are a primitive group of meteorites, which contain abundant organic material and provide a unique natural record of prebiotic chemical evolution. This material comprises a varied suite of soluble organic compounds that are similar, sometimes identical, to those found in the biosphere, such as amino acids, carboxylic acids, and sugar derivatives. Some amino acids of this suite also show L-enantiomeric excesses, and suggest the possibility they may have contributed to terrestrial homochirality by direct input of meteoritic material to the early Earth. This optical activity appears to be limited to the subgroup of alpha-methyl amino acids which, although not common in the extant biosphere, would have been well suited to provide the early earth with both enantiomeric excesses and means for their amplification by subsequent chemical evolution. We can also envision this exogenous delivery of carbonaceous material by meteorites and comets as having coincided with the endogenous formation of prebiotic precursors and influenced their evolution by complementary reactions or catalysis.     

Combinatorial model for the formation of body plans in higher metazoan taxa: Paleontological insight

The body plans of higher metazoan taxa were formed during a short time (on the geological time scale) by combination of the previously developed characters. The combinations were realized as a result of manifestation of latent characters in adults through various heterochronies. This resulted in mosaic evolution and concealment of intermediate forms. Many characters of new body plans appeared in the ancestral taxon and their various combinations in the newly established taxa formed the archaic diversity. The maximum rank of newly appearing higher taxa decreased with geological time. The evolution of metazoans passed from the development of the general body plan to less significant details and appearance of body plans describing taxa of lower ranks. New body plans of higher taxa were superposed on the old body plan rather than replaced it, extending with time the subordination of body plans and respective hierarchy of taxa. Aromorphoses are always connected with the appearance of a new body plan. The appearance of new taxa and an increase in morphological diversity mostly occurred at certain boundaries in the development of the biota, which were connected with a sharp increase in the previously limited resources.     

Did the evolution of the phytoplankton fuel the diversification of the marine biosphere?

We discuss the possible links between the fossil record of marine biodiversity, nutrient availability and primary productivity. The parallelism of the fossil records of marine phytoplankton and faunal biodiversity implicates the quantity (primary productivity) and quality (stoichiometry) of phytoplankton as being critical to the diversification of the marine biosphere through the Phanerozoic. The relatively subdued marine biodiversity of the Palaeozoic corresponds to a time of relatively low macronutrient availability and poor food quality of the phytoplankton as opposed to the diversification of the Modern Fauna through the Mesozoic–Cenozoic. Increasing nutrient runoff to the oceans through the Phanerozoic resulted from orogeny, the emplacement of Large Igneous Provinces (LIPs), the evolution of deep-rooting forests and the appearance of more easily decomposable terrestrial organic matter that enhanced weathering. Positive feedback by bioturbation of an expanding benthos played a critical role in evolving biogeochemical cycles by linking the oxidation of dead organic matter and the recycling of nutrients back to the water column where they could be re-utilized. We assess our conclusions against a recently published biogeochemical model for geological time-scales. Major peaks of marine diversity often occur near rising or peak fluxes of silica, phosphorus and dissolved reactive oceanic phosphorus; either major or minor ⁸⁷Sr/⁸⁶Sr peaks; and frequently in the vicinity of major (Circum-Atlantic Magmatic Province) and minor volcanic events, some of which are associated with Oceanic Anoxic Events. These processes appear to be scale-dependent in that they lie on a continuum between biodiversification on macroevolutionary scales of geological time and mass extinction.     

Formation of evolutionary approach as an explanatory principle for ecology

Although the connection of ecology with evolutionary idea and specifically with Darwinism was proclaimed for a long time it seems that Herbert Spencer's approach with its emphasize on natural equilibrium was much more often used as its real theoretical base. Elements of Darwinian approach appeared only in 1920-30s in works of those few researchers who studying the distribution and population dynamics of different species tried to understand general mechanisms providing their continuing existence. Later, in the middle of 1950s the first attempts were undertaken to consider the population life history (primarily the age specific schedule of death and reproduction) as a result of natural selection aimed to maintain the necessary level of fitness. A special attention in these studies that burgeoned in 1980-90s was paid to looking for various trade-offs between particular parameters of life history, e.g., between the survival of juveniles and fecundity of adults. The problem of life history optimization became central for the whole branch of science named "evolutionary ecology". Though traditionally this branch is connected with Darwinism, it is rooted rather in Spencer's ideas on moving equilibrium and deals more with static than dynamic. Disproportionately less attention was paid to the evolution of communities since these formations could be hardly interpreted as units of Darwinian selection. Moreover, the ecologists dealing with biosphere as a unified biogeochemical system began insist on "nondarwinian" nature of its evolution. The author considers this opinion as not sufficiently grounded. Darwin's ideas about unavoidable exponential growth, intrinsic for any population, consequent deficiency of resources, and differential survival and reproduction of individuals are still useful while studying the evolution of living organisms (phylogenetics) or the development of biosphere as a global ecosystem.     

The science of the biosphere

This paper considers the needs and potentials for the development of the biosphere. An emphasis is placed on the unusual qualities of the biosphere, such as important time lags, interactions between life and its environment at large scales, and biological evolution, which has led to large scale changes in the environment during the Earth's history. These qualities require a different approach to the development of a theory for this large scale system than has been used in the past, when the biosphere was treated as a steady-state, quasilinear system. Other aspects of the development of the science of the biosphere, including the use of remote sensing, are reviewed, and the application of these techniques to the estimation of certain biological variables is discussed.     

Evolutionary ecology of periodical insects

To be periodical, a species must have a fixed life cycle length and adults must appear synchronously, reproduce only once, and die. The consequence of this life history is that, at a given location, adults of a periodical species will be absent or rare in some years and abundant in others. The relative scarcity of periodical Insect species suggests that periodicity does not evolve easily. The major obstacle to its evolution is selection favoring life cycles In which the offspring of any given female appear over a two- or three-year period. Chance events which disrupt this 'bet-hedging' strategy set the stage for periodicity. Mathematical models predict that, given certain initial conditions, intraspecific competition and predation favor its development. Recent studies suggest that periodicity is rarely perfect but that it can persist in the face of limited gene flow through time.     

Stratigraphical classification and all that

Quantitative treatment of the geological sciences must remain limited; there continues to be need for a language of words. This is keenly felt in stratigraphy, where the practising geologist is dismayed by the effusions of the stratigraphical philosophers. The situation, in so far as it appears to remain in some ways obscure or troublesome, is briefly reviewed in terms of lithostratigraphy. biostratigraphy. and chronostratigraphy. A revised version of a controversial diagram is presented, in which the role of the boundary stratotype as anchor point is believed to be clarified. Finally a synthesis is attempted of relationships between the various stratigraphical procedures and the provision of dates in years through the parallel discipline of geochronometry.     

Human well-being differs by community type: Toward reference points in a human well-being indicator useful for decision support

Human activity has growing impacts on the natural capital humans depend on for existence. While many of these impacts are regional, national, or international in scope, it is increasingly evident that decisions made at the local community level are also important. Yet, understanding the impacts of local decisions, as well as how to correct or mitigate these impacts, can be problematic, as communities differ in resources, priorities, dependencies on natural capital, and even opinions about whether these impacts actually affect quality of life. Every community has unique characteristics, however effective decision support at the community level requires common reference points in measures of human well-being upon which to base decision support. We have developed a community classification system that is intended to find such common ground in community characteristics and tie these common elements to measures of human well-being. This community classification system was developed in the USA with publically available data on resource dependence, socio-economic composition, and existence of natural capital. The resulting classification was applied to coastal communities at the county level and then used to predict human well-being based on an existing human well-being index. Coastal communities were separated into eight characteristics groups based on Bayesian cluster analysis. Classification groups were found to be associated with significant differences in human well-being. More importantly, significant differences in specific elements of well-being were associated with key community characteristics, such as population density and economic dependence on local natural resources. In particular, social cohesion and the leisure time were strong elements of well-being in low density communities with high natural resource dependence but this association weakened as population densities and economically diversity increased. These sorts of commonalities in community type that can be tied to differences in human well-being are important because they provide clear ties to environmental service flows, as well as a meaningful reference point from which to measure the local impacts of decisions as changes in community-specific human well-being.