Franklin M. Harold
- Published in print:
- 2014
- Published Online:
- May 2015
- ISBN:
- 9780226174143
- eISBN:
- 9780226174310
- Item type:
- chapter
- Publisher:
- University of Chicago Press
- DOI:
- 10.7208/chicago/9780226174310.003.0007
- Subject:
- Biology, Biochemistry / Molecular Biology
The origin of eukaryotic cells is a mystery second only to the origin of life itself. The problem is that eukaryotes make up a distinctive clade, conspicuously different from prokaryotes, yet they ...
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The origin of eukaryotic cells is a mystery second only to the origin of life itself. The problem is that eukaryotes make up a distinctive clade, conspicuously different from prokaryotes, yet they share genes and traits with both Bacteria and Archaea. There is general agreement that eukaryotes are chimaeric, since mitochondria and plastids derive from Bacterial endosymbionts; but consensus ends here. Disputes swirl around the nature of the cells that hosted those symbionts, the nature and timing of their association, and the role of the symbionts in generating eukaryotic complexity. This long-running controversy may now be approaching a resolution that combines ideas from several camps. The emerging synthesis postulates an “urkaryote” of Archaeal affinities that diverged very early and came to make its living by scavenging and predation upon the primary producers of organic matter. Acquisition of the Bacterial precursors of mitochondria enhanced the consortium's energy economy, and underwrote the rise of complex eukaryotic cells.Less
The origin of eukaryotic cells is a mystery second only to the origin of life itself. The problem is that eukaryotes make up a distinctive clade, conspicuously different from prokaryotes, yet they share genes and traits with both Bacteria and Archaea. There is general agreement that eukaryotes are chimaeric, since mitochondria and plastids derive from Bacterial endosymbionts; but consensus ends here. Disputes swirl around the nature of the cells that hosted those symbionts, the nature and timing of their association, and the role of the symbionts in generating eukaryotic complexity. This long-running controversy may now be approaching a resolution that combines ideas from several camps. The emerging synthesis postulates an “urkaryote” of Archaeal affinities that diverged very early and came to make its living by scavenging and predation upon the primary producers of organic matter. Acquisition of the Bacterial precursors of mitochondria enhanced the consortium's energy economy, and underwrote the rise of complex eukaryotic cells.
Lawrence E. Hunter
- Published in print:
- 2009
- Published Online:
- August 2013
- ISBN:
- 9780262013055
- eISBN:
- 9780262255288
- Item type:
- chapter
- Publisher:
- The MIT Press
- DOI:
- 10.7551/mitpress/9780262013055.003.0006
- Subject:
- Biology, Biochemistry / Molecular Biology
This chapter introduces the structures and processes of the eukaryotes, the branch of life that includes all plants and animals. It discusses eukaryotic gene structure and transcription, components ...
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This chapter introduces the structures and processes of the eukaryotes, the branch of life that includes all plants and animals. It discusses eukaryotic gene structure and transcription, components of the eukaryotic cell, and lifestyles of the single-celled eukaryote.Less
This chapter introduces the structures and processes of the eukaryotes, the branch of life that includes all plants and animals. It discusses eukaryotic gene structure and transcription, components of the eukaryotic cell, and lifestyles of the single-celled eukaryote.
T. Gánti
- Published in print:
- 2003
- Published Online:
- April 2010
- ISBN:
- 9780198507260
- eISBN:
- 9780191584886
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198507260.003.0001
- Subject:
- Biology, Evolutionary Biology / Genetics
This chapter introduces some of the concepts central to Génti's main argument, and illustrates how the core problem of the nature of the living state applies at many levels of life. Topics discussed ...
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This chapter introduces some of the concepts central to Génti's main argument, and illustrates how the core problem of the nature of the living state applies at many levels of life. Topics discussed include the chemoton, life at the prokaryotic level, life at the animal level, and eukaryotic cells and fungi.Less
This chapter introduces some of the concepts central to Génti's main argument, and illustrates how the core problem of the nature of the living state applies at many levels of life. Topics discussed include the chemoton, life at the prokaryotic level, life at the animal level, and eukaryotic cells and fungi.
Andrew F. G. Bourke
- Published in print:
- 2011
- Published Online:
- December 2013
- ISBN:
- 9780199231157
- eISBN:
- 9780191774553
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199231157.003.0004
- Subject:
- Biology, Evolutionary Biology / Genetics
Pathways of social group formation are poorly known for the origin of the eukaryotic cell, sexual reproduction, and many interspecific mutualisms. In the origin of multicellularity and eusociality, ...
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Pathways of social group formation are poorly known for the origin of the eukaryotic cell, sexual reproduction, and many interspecific mutualisms. In the origin of multicellularity and eusociality, social group formation has usually occurred via a subsocial pathway (association of parents and offspring), with a semisocial pathway (association of same-generation organisms) occurring occasionally. The essential genetic condition for social group formation in groups exhibiting altruism is that relatedness should be positive – a prediction overwhelmingly supported by available evidence in the case of both the origin of multicellularity and the origin of eusociality. Non-genetic factors (ecological or synergistic) facilitate social group formation by increasing the benefits of grouping and the costs of living singly. Ecological factors promoting the formation of multicellular organisms and eusocial societies include environmental stresses and predator pressure. A major synergistic factor promoting the formation of multicellular organisms, eusocial societies, and interspecific mutualisms is division of labour.Less
Pathways of social group formation are poorly known for the origin of the eukaryotic cell, sexual reproduction, and many interspecific mutualisms. In the origin of multicellularity and eusociality, social group formation has usually occurred via a subsocial pathway (association of parents and offspring), with a semisocial pathway (association of same-generation organisms) occurring occasionally. The essential genetic condition for social group formation in groups exhibiting altruism is that relatedness should be positive – a prediction overwhelmingly supported by available evidence in the case of both the origin of multicellularity and the origin of eusociality. Non-genetic factors (ecological or synergistic) facilitate social group formation by increasing the benefits of grouping and the costs of living singly. Ecological factors promoting the formation of multicellular organisms and eusocial societies include environmental stresses and predator pressure. A major synergistic factor promoting the formation of multicellular organisms, eusocial societies, and interspecific mutualisms is division of labour.
Andrew F. G. Bourke
- Published in print:
- 2011
- Published Online:
- December 2013
- ISBN:
- 9780199231157
- eISBN:
- 9780191774553
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199231157.003.0001
- Subject:
- Biology, Evolutionary Biology / Genetics
A series of major transitions in evolution has generated the biological hierarchy (e.g., genes in cells, cells in organisms, organisms in societies) observed today. Each transition requires that ...
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A series of major transitions in evolution has generated the biological hierarchy (e.g., genes in cells, cells in organisms, organisms in societies) observed today. Each transition requires that previously selfish, free-living individuals join together to form a group resembling an individual in its own right. This book seeks to identify the principles of social evolution that underlie the major transitions, focusing on the evolution of the eukaryotic cell, sexual reproduction, multicellularity, eusociality, and interspecific mutualisms. It suggests that each major transition has three stages – social group formation, social group maintenance, and social group transformation. Using Hamilton's inclusive fitness theory (kin selection theory) as its conceptual foundation, the book investigates two underexplored issues. First, to what extent do common principles operate at each stage of the major transitions and what is the evidence for their operation; and second, what are the principles underlying social group transformation?Less
A series of major transitions in evolution has generated the biological hierarchy (e.g., genes in cells, cells in organisms, organisms in societies) observed today. Each transition requires that previously selfish, free-living individuals join together to form a group resembling an individual in its own right. This book seeks to identify the principles of social evolution that underlie the major transitions, focusing on the evolution of the eukaryotic cell, sexual reproduction, multicellularity, eusociality, and interspecific mutualisms. It suggests that each major transition has three stages – social group formation, social group maintenance, and social group transformation. Using Hamilton's inclusive fitness theory (kin selection theory) as its conceptual foundation, the book investigates two underexplored issues. First, to what extent do common principles operate at each stage of the major transitions and what is the evidence for their operation; and second, what are the principles underlying social group transformation?
John L. Hall and Lynn Margulis
- Published in print:
- 2011
- Published Online:
- August 2013
- ISBN:
- 9780262015394
- eISBN:
- 9780262312462
- Item type:
- chapter
- Publisher:
- The MIT Press
- DOI:
- 10.7551/mitpress/9780262015394.003.0014
- Subject:
- Biology, Evolutionary Biology / Genetics
This chapter presents exciting new evidence for and an interpretation of life’s deepest, most potentially profound level of chimerical union. It shows that genetic and molecular biological evidence ...
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This chapter presents exciting new evidence for and an interpretation of life’s deepest, most potentially profound level of chimerical union. It shows that genetic and molecular biological evidence supports the notion of the oldest organisms that merged in the formation of the modern nucleated (eukaryotic) cell, and arguably the most important for intracellular motility, was, and still is, the remnant spirochete. This chapter shows that kinetosomes, centrioles, and centrosomes display tantalizing evidence of a common origin. It hypothesizes that the undulipodium evolved from a common spirochete ancestor.Less
This chapter presents exciting new evidence for and an interpretation of life’s deepest, most potentially profound level of chimerical union. It shows that genetic and molecular biological evidence supports the notion of the oldest organisms that merged in the formation of the modern nucleated (eukaryotic) cell, and arguably the most important for intracellular motility, was, and still is, the remnant spirochete. This chapter shows that kinetosomes, centrioles, and centrosomes display tantalizing evidence of a common origin. It hypothesizes that the undulipodium evolved from a common spirochete ancestor.
Andrew Maniotis
- Published in print:
- 2011
- Published Online:
- August 2013
- ISBN:
- 9780262015394
- eISBN:
- 9780262312462
- Item type:
- chapter
- Publisher:
- The MIT Press
- DOI:
- 10.7551/mitpress/9780262015394.003.0015
- Subject:
- Biology, Evolutionary Biology / Genetics
This chapter explains how bacterial genophore evolved into animal (including human) chromosomes. It reviews the transition from the bacterial carrier of DNA to the chromosomes within the more complex ...
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This chapter explains how bacterial genophore evolved into animal (including human) chromosomes. It reviews the transition from the bacterial carrier of DNA to the chromosomes within the more complex eukaryotic cells. This chapter shows that mechanical tension among continuously attached chromosomes is the essential signal for the sets of chromosomes to move in a coordinated way as “mitotic plates.” It suggests that the physicochemical basis for the inheritance of the human sensory system is coded in the DNA of the genome.Less
This chapter explains how bacterial genophore evolved into animal (including human) chromosomes. It reviews the transition from the bacterial carrier of DNA to the chromosomes within the more complex eukaryotic cells. This chapter shows that mechanical tension among continuously attached chromosomes is the essential signal for the sets of chromosomes to move in a coordinated way as “mitotic plates.” It suggests that the physicochemical basis for the inheritance of the human sensory system is coded in the DNA of the genome.
Kevin C. Roach, Benjamin D. Ross, and Harmit S. Malik
- Published in print:
- 2012
- Published Online:
- December 2013
- ISBN:
- 9780199642274
- eISBN:
- 9780191774751
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199642274.003.0009
- Subject:
- Biology, Evolutionary Biology / Genetics
Centromeres and the kinetochore proteins that bind them are required for chromosome segregation during eukaryotic cell division. Despite this conserved function, both centromeric DNA and kinetochore ...
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Centromeres and the kinetochore proteins that bind them are required for chromosome segregation during eukaryotic cell division. Despite this conserved function, both centromeric DNA and kinetochore proteins evolve rapidly. This chapter hypothesizes that this paradox can be explained by an on-going conflict between selfish centromeric DNA elements and the DNA binding proteins of the kinetochore. In this model, centromeres are able to gain an evolutionary advantage by promoting their own transmission during asymmetric female meiosis. Deleterious consequences of this selfish behaviour in turn select for variant kinetochore proteins that can suppress centromeric imbalances. This conflict, termed ‘Centromere Drive’, provides an explanation for observed differences in evolutionary rates between components of the kinetochore, and makes predictions about which taxa might experience accelerated centromeric evolution.Less
Centromeres and the kinetochore proteins that bind them are required for chromosome segregation during eukaryotic cell division. Despite this conserved function, both centromeric DNA and kinetochore proteins evolve rapidly. This chapter hypothesizes that this paradox can be explained by an on-going conflict between selfish centromeric DNA elements and the DNA binding proteins of the kinetochore. In this model, centromeres are able to gain an evolutionary advantage by promoting their own transmission during asymmetric female meiosis. Deleterious consequences of this selfish behaviour in turn select for variant kinetochore proteins that can suppress centromeric imbalances. This conflict, termed ‘Centromere Drive’, provides an explanation for observed differences in evolutionary rates between components of the kinetochore, and makes predictions about which taxa might experience accelerated centromeric evolution.
