Paleolimnology in Deep Time: The Evolution of Lacustrine Ecosystems

2003 ◽  
Author(s):  
Andrew S. Cohen
Keyword(s):  
Fossil Record ◽  
World Ocean ◽  
Biological Evolution ◽  
Body Distribution ◽  
Freshwater Organisms ◽  
History Of ◽  
Living Organisms ◽  
Lake Basins ◽  
Lake Beds

Most lakes are geologically ephemeral; even the longest-lived individual lakes persist only for tens of millions of years. However there is a continuity to lake systems that transcends the geologically short history of individual lake basins. This continuity comes from the long-term biological evolution of life in freshwater, and fittingly, forms the final subject of this treatment of paleolimnology. Like the oceans, lakes have provided habitats for living organisms for most of the earth’s history. Yet the patterns of aquatic ecosystem evolution in rivers and lakes have differed dramatically from those of the oceans. In large part this can be traced to the fundamentally ephemeral nature of most continental aquatic habitats and the ‘‘disconnectedness’’ in both time and space that exists between individual lakes and rivers compared with the world ocean. This pattern of temporal and spatial patchiness in water body distribution on the continents has shaped the evolution of lacustrine species and communities. Some understanding of this history can be gleaned from the study of modern ecology and molecular genetics of living freshwater organisms. But to understand long-term trends in lacustrine biodiversity and their relationship to the history of the lacustrine environment we must turn to the pre- Quaternary fossil record. Understanding this history, the timing and tempo of major species diversification and extinction events, and the evolution of key ecological innovations is critical for correctly interpreting ancient lake deposits. The fossil record of pre-Quaternary lakes is more difficult to interpret than that of more recent lake basins. Robust phylogenies are largely unavailable for clades of ancient lacustrine fossils, hindering our ability to test hypotheses of evolutionary ecology, although that situation hopefully will improve in coming years. Many major clades of fossil lacustrine organisms are extinct, and ecologies must be inferred from their depositional context. Even for organisms that have close-living relatives, our certainty in making inferences about habitat and relationship with other species weakens as we go back in time. Also the record we have to work with deteriorates with age, the result of (a) a declining volume of lake beds available for study with increasing age, (b) difficulties associated with processing lithified lake beds for their fossil content, and (c) an increasing likelihood of destruction by diagenesis with increasing age.

scholarly journals Tracking interspecies transmission and long-term evolution of an ancient retrovirus using the genomes of modern mammals

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
William E Diehl ◽  
Nirali Patel ◽  
Kate Halm ◽  
Welkin E Johnson
Keyword(s):  
Fossil Record ◽  
Viral Infections ◽  
Endogenous Retroviruses ◽  
Interspecies Transmission ◽  
Viral Spread ◽  
Protein Functions ◽  
History Of ◽  
Mammalian Genomes ◽  
Retroviral Infections

Mammalian genomes typically contain hundreds of thousands of endogenous retroviruses (ERVs), derived from ancient retroviral infections. Using this molecular 'fossil' record, we reconstructed the natural history of a specific retrovirus lineage (ERV-Fc) that disseminated widely between ~33 and ~15 million years ago, corresponding to the Oligocene and early Miocene epochs. Intercontinental viral spread, numerous instances of interspecies transmission and emergence in hosts representing at least 11 mammalian orders, and a significant role for recombination in diversification of this viral lineage were also revealed. By reconstructing the canonical retroviral genes, we identified patterns of adaptation consistent with selection to maintain essential viral protein functions. Our results demonstrate the unique potential of the ERV fossil record for studying the processes of viral spread and emergence as they play out across macro-evolutionary timescales, such that looking back in time may prove insightful for predicting the long-term consequences of newly emerging viral infections.

Evolutionary History of Plant Lipolytic Enzymes

2018 ◽  
pp. 155-178
Keyword(s):  
Higher Plants ◽  
Evolutionary Relationship ◽  
Biological Evolution ◽  
Sequence Motifs ◽  
Multiple Sequence ◽  
Lipolytic Enzymes ◽  
Conserved Sequence ◽  
Potential Applications ◽  
History Of ◽  
Living Organisms

The discovery of enzymes with lipolytic activities in all kingdoms of life from prokaryote to eukaryote species raises the possibility of the presence of an evolutionary relationship history of these proteins among many species of various living organisms. The chapter suggests a strategy based on the phylogenetic distribution and homology conservation in plant lipolytic enzymes for possible depiction of their biological evolution. Extensive databases and online resources for lipidomics and related areas are useful tools to analyze the different lipolytic enzymes in the three major super kingdoms of life, including higher plants kingdom and confined organisms such as algae that have recently gained much interest due to their promising potential applications in lipids hydrolysis and biosynthesis. Multiple sequence alignments of the identified lipolytic enzymes from databases could serve to the identification of globally conserved residues as well as conserved sequence motifs. Estimation of evolutionary distance between the various identified lipolytic enzymes could also be carried out to better understand the pattern of evolution.

Pteridophyte success and past biota—a palaeobotanist's approach

1985 ◽  
Vol 86 ◽  
pp. 423-430
Author(s):  
B. A. Thomas
Keyword(s):  
Fossil Record ◽  
Geological History ◽  
Term Survival ◽  
Long Term Survival ◽  
Amount Of Information ◽  
The Past ◽  
History Of

SynopsisThe success of plants which lived in the past should be assessed differently from that of living plants as time is an additional important factor. Success may therefore be judged in one period of time or throughout the whole geological history of the plants.Limitations of the fossil record through plant fragmentation, lack of preservation and incomplete preservation severely restrict the amount of information available. However, accepting these problems, there are four major ways in which plants may be judged: long term survival, repeated specialisation, dominance and adaptability. Examples are given of pteridophytes that exhibit success in these four ways.

Evolution of Biomineralization

1989 ◽  
Author(s):  
Heinz A. Lowenstam ◽  
Stephen Weiner
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Molecular Structures ◽  
Comparative Biology ◽  
Crucial Importance ◽  
Hard Part ◽  
History Of ◽  
Acidic Proteins ◽  
Living Organisms ◽  
Time And Being

Biomineralization among living organisms is widespread, occurring in both prokaryotes and eukaryotes. It is diverse with some 60 or so minerals known to be formed by organisms under a wide variety of conditions. They are deposited at many different locations both inside and outside cells. Biomineralization occurs on such an enormous scale that it influences processes in the biosphere itself. It is, therefore, of interest to determine how this all came about—the evolution of biomineralization. The evolutionary history of biomineralization is a fascinating subject in its own right, which is the primary reason for including it in this book. However, a well-substantiated understanding of this subject is also of crucial importance to the interpretation of many aspects of research into the mechanisms of biomineralization in living organisms. An example is the observation by Veis et al. (1986) that antibodies raised against the rat incisor acidic proteins, phosphophoryns, crossreact with proteins extracted from a sea urchin test. The proteins presumably share some similar molecular structures. Did they inherit them from a common ancestor or did they evolve independently from each other to fulfill similar functions? This type of question can be asked about many comparative studies in biomineralization between phyla or even within lower taxa of the same phyla. As long as we do not have answers to these questions, the powerful tool of comparative biology in biomineralization is compromised. Studying the evolution of biomineralization has one enormous advantage over many other topics in evolutionary biology; the very material that we are interested in has the best chance of surviving the vagaries of time and being preserved in the fossil record. The fossil record at least during the last 600 million years or so is, for the most part, a documentation of remnants of the history of mineralized hard part formation by organisms. Thus, the evolution of biomineralization is one topic that can, and that should be based on the direct documentation of the fossil record. This is the way it is presented in this chapter. The corollary of this statement is also worth considering. The fossil record should be interpreted bearing in mind the evolution of biomineralization.

Amino Acids and Proteins from Fossils

1988 ◽  
Vol 1 ◽  
pp. 20-33 ◽  
Author(s):  
Gordon B. Curry
Keyword(s):  
Amino Acids ◽  
Relative Stability ◽  
Fossil Record ◽  
Organic Molecules ◽  
Soft Tissues ◽  
Building Blocks ◽  
Biological Molecules ◽  
Long Term Stability ◽  
Living Organisms

The fossilization potential of organic molecules is extremely variable. Some organic compounds which are very common in living organisms are extremely rare in the fossil record, and are only preserved under exceptional conditions. For example DNA, despite its abundance in living organisms, is apparently only rarely preserved in recognizable form as fossils, primarily because it is concentrated in vulnerable soft-tissues, and the molecule itself is highly reactive and therefore easily broken down. In contrast the recognizable remains of molecules such as proteins, lipids and certain pigments are extremely abundant in the fossil record, to the extent that a group of fossilized molecules derived from bacterial cell walls is present in quantities which exceed that of the total organic carbon in the present day biosphere. Such preservation reflects the inherent relative stability of the molecular structure, or at least the relative stability of the building blocks of which it is constructed. Even simple biological molecules tend to be constructed from smaller molecular subunits, and their long-term stability, and ultimately their fossilization potential, depends both on the strength of the bonding between these smaller modular building blocks as well as on the durability of the building blocks themselves if they become dissociated during or after fossilization. As would be expected from their geological record, the constituent nucleic acids of DNA are much less stable than the amino acids which make up proteins.

The Historical Turn in Southeastern Archaeology

2020 ◽  
Keyword(s):  
North America ◽  
History Of Archaeology ◽  
Colonial History ◽  
Historical Trends ◽  
Southeastern Archaeology ◽  
Conceptual Frame ◽  
Historical Turn ◽  
History Of ◽  
Living Organisms

The primary purpose of this edited volume is to formalize as a theory the historical turn in southeastern archaeology (and American archaeology) and provide a number of case studies illustrating the use of the theory in the region. In previous decades, archaeologists and other scholars studying what is commonly termed “prehistoric” America emphasized long-term, evolutionary change and adaptation, and archaeologists conceptualized pre-colonial societies like living organisms adapting to environmental challenges rather than as collections of people responding to historical trends and forces. The history of archaeology and the reasons for this conceptual frame are complex and deeply rooted in misconceptions about indigenous people as unchanging, static “people without history” who disappeared soon after Europeans arrived in North America. Today, however, archaeologists are combining evolutionary processes with a new understanding that so-called prehistory was also historical, contingent, and local, and historians are looking to the ancient past to better understand Indian societies of the historic era. In other words, scholars now understand that the historic and “prehistoric” eras were not categorically different and that people across this divide were subject to similar historical forces. This historicizing of prehistory represents a profound shift in our way of thinking about precolonial and colonial history and begins to erase the false divide between ancient America and colonial and even contemporary America.

Cultural evolution, the postbiological universe and SETI

2003 ◽  
Vol 2 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Steven J. Dick
Keyword(s):  
Cultural Evolution ◽  
Biological Evolution ◽  
General Nature ◽  
Extraterrestrial Life ◽  
Cosmic Evolution ◽  
History Of ◽  
The Subject ◽  
The Universe ◽  
Biological Universe

The Biological Universe (Dick 1996) analysed the history of the extraterrestrial life debate, documenting how scientists have assessed the chances of life beyond Earth during the 20th century. Here I propose another option – that we may in fact live in a postbiological universe, one that has evolved beyond flesh and blood intelligence to artificial intelligence that is a product of cultural rather than biological evolution. MacGowan & Ordway (1966), Davies (1995) and Shostak (1998), among others, have broached the subject, but the argument has not been given the attention it is due, nor has it been carried to its logical conclusion. This paper argues for the necessity of long-term thinking when contemplating the problem of intelligence in the universe. It provides arguments for a postbiological universe, based on the likely age and lifetimes of technological civilizations and the overriding importance of cultural evolution as an element of cosmic evolution. And it describes the general nature of a postbiological universe and its implications for the search for extraterrestrial intelligence.

scholarly journals Retroviruses drive the rapid evolution of mammalianAPOBEC3genes

2019 ◽  
Vol 117 (1) ◽  
pp. 610-618 ◽  
Author(s):  
Jumpei Ito ◽  
Robert J. Gifford ◽  
Kei Sato
Keyword(s):  
Gene Family ◽  
Fossil Record ◽  
Driving Force ◽  
Mammalian Species ◽  
Rapid Evolution ◽  
Endogenous Retroviruses ◽  
Mammalian Evolution ◽  
History Of ◽  
Mammalian Genomes

APOBEC3(A3) genes are members of theAID/APOBECgene family that are found exclusively in mammals.A3genes encode antiviral proteins that restrict the replication of retroviruses by inducing G-to-A mutations in their genomes and have undergone extensive amplification and diversification during mammalian evolution. Endogenous retroviruses (ERVs) are sequences derived from ancient retroviruses that are widespread mammalian genomes. In this study we characterize theA3repertoire and use the ERV fossil record to explore the long-term history of coevolutionary interaction between A3s and retroviruses. We examine the genomes of 160 mammalian species and identify 1,420AID/APOBEC-related genes, including representatives of previously uncharacterized lineages. We show thatA3genes have been amplified in mammals and that amplification is positively correlated with the extent of germline colonization by ERVs. Moreover, we demonstrate that the signatures of A3-mediated mutation can be detected in ERVs found throughout mammalian genomes and show that in mammalian species with expandedA3repertoires, ERVs are significantly enriched for G-to-A mutations. Finally, we show thatA3amplification occurred concurrently with prominent ERV invasions in primates. Our findings establish that conflict with retroviruses is a major driving force for the rapid evolution of mammalianA3genes.

The Tempo and mode(S) of Prebiotic Evolution

1997 ◽  
Vol 161 ◽  
pp. 419-429 ◽  
Author(s):  
Antonio Lazcano
Keyword(s):  
Origin Of Life ◽  
Organic Compounds ◽  
Biological Evolution ◽  
Current Evidence ◽  
Early Diversification ◽  
Time Period ◽  
The Galaxy ◽  
History Of ◽  
Widespread Phenomenon ◽  
The Origin Of Life

AbstractDifferent current ideas on the origin of life are critically examined. Comparison of the now fashionable FeS/H2S pyrite-based autotrophic theory of the origin of life with the heterotrophic viewpoint suggest that the later is still the most fertile explanation for the emergence of life. However, the theory of chemical evolution and heterotrophic origins of life requires major updating, which should include the abandonment of the idea that the appearance of life was a slow process involving billions of years. Stability of organic compounds and the genetics of bacteria suggest that the origin and early diversification of life took place in a time period of the order of 10 million years. Current evidence suggest that the abiotic synthesis of organic compounds may be a widespread phenomenon in the Galaxy and may have a deterministic nature. However, the history of the biosphere does not exhibits any obvious trend towards greater complexity or «higher» forms of life. Therefore, the role of contingency in biological evolution should not be understimated in the discussions of the possibilities of life in the Universe.

Atypical Femoral Fracture in McCune-Albright Syndrome

2020 ◽  
Vol 7 (3) ◽  
pp. 147-152
Author(s):  
Salman Ghaffari ◽  
◽  
Mehran Razavipour ◽  
Parastoo Mohammad Amini ◽  
◽  
...  
Keyword(s):  
Femoral Fracture ◽  
Dynamic Compression ◽  
Plate Fixation ◽  
Medullary Canal ◽  
Mccune Albright Syndrome ◽  
Café Au Lait Spots ◽  
History Of ◽  
Albright Syndrome ◽  
Mccune Albright

McCune-Albright Syndrome (MAS) is characterized by endocrinopathies, café-au-lait spots, and fibrous dysplasia. Bisphosphonates are the most prescribed treatment for reducing the pain but their long-term use has been associated with atypical fractures of cortical bones like femur in patients. We present a 23-year-old girl diagnosed with MAS. She had an atypical mid-shaft left femoral fracture that happened during simple walking. She also had a history of long-term use of alendronate. Because of the narrow medullary canal, we used 14 holes hybrid locking plate for the lateral aspect of the thigh to fix the fracture and 5 holes dynamic compression plate (instead of the intramedullary nail) in the anterior surface to double fix it, reducing the probability of device failure. With double plate fixation and discontinuation of alendronate, the complete union was achieved five months after surgery

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