scholarly journals The order of trait emergence in the evolution of cyanobacterial multicellularity

2020 ◽  
Author(s):  
Katrin Hammerschmidt ◽  
Giddy Landan ◽  
Fernando Domingues KüMmel Tria ◽  
Jaime Alcorta ◽  
Tal Dagan
Keyword(s):  
Division Of Labor ◽  
Phenotypic Trait ◽  
Metabolic Capacity ◽  
Evolutionary Transitions ◽  
Differentiated Cells ◽  
Labor Theory ◽  
Significant Events ◽  
Reproductive Life ◽  
History Of ◽  
Multicellular Organisms

Abstract The transition from unicellular to multicellular organisms is one of the most significant events in the history of life. Key to this process is the emergence of Darwinian individuality at the higher level: groups must become single entities capable of reproduction for selection to shape their evolution. Evolutionary transitions in individuality are characterized by cooperation between the lower level entities and by division of labor. Theory suggests that division of labor may drive the transition to multicellularity by eliminating the trade-off between two incompatible processes that cannot be performed simultaneously in one cell. Here we examine the evolution of the most ancient multicellular transition known today, that of cyanobacteria, where we reconstruct the sequence of ecological and phenotypic trait evolution. Our results show that the prime driver of multicellularity in cyanobacteria was the expansion in metabolic capacity offered by nitrogen fixation, which was accompanied by the emergence of the filamentous morphology and succeeded by a reproductive life cycle. This was followed by the progression of multicellularity into higher complexity in the form of differentiated cells and patterned multicellularity.

scholarly journals The order of trait emergence in the evolution of cyanobacterial multicellularity

2019 ◽  
Author(s):  
Katrin Hammerschmidt ◽  
Giddy Landan ◽  
Fernando Domingues Kümmel Tria ◽  
Jaime Alcorta ◽  
Tal Dagan
Keyword(s):  
Division Of Labor ◽  
Phenotypic Trait ◽  
Evolutionary Transition ◽  
Evolutionary Transitions ◽  
Differentiated Cells ◽  
Labor Theory ◽  
Significant Events ◽  
Reproductive Life ◽  
History Of ◽  
Multicellular Organisms

AbstractThe transition from unicellular to multicellular organisms is one of the most significant events in the history of life. Key to this process is the emergence of Darwinian individuality at the higher level: groups must become single entities capable of reproduction for selection to shape their evolution. Evolutionary transitions in individuality are characterized by cooperation between the lower level entities and by division of labor. Theory suggests that division of labor may drive the transition to multicellularity by eliminating the trade-off between two incompatible processes that cannot be performed simultaneously in one cell. Here we examine the evolution of the most ancient multicellular transition known today, that of cyanobacteria, where we reconstruct the sequence of ecological and phenotypic trait evolution. Our results show that the prime driver of multicellularity in cyanobacteria was the expansion in metabolic capacity offered by nitrogen fixation, which was accompanied by the emergence of the filamentous morphology and succeeded by a reproductive life cycle. This was followed by the progression of multicellularity into higher complexity in the form of differentiated cells and patterned multicellularity.Significance StatementThe emergence of multicellularity is a major evolutionary transition. The oldest transition, that of cyanobacteria, happened more than 3 to 3.5 billion years ago. We find N2 fixation to be the prime driver of multicellularity in cyanobacteria. This innovation faced the challenge of incompatible metabolic processes since the N2 fixing enzyme (nitrogenase) is sensitive to oxygen, which is abundantly found in cyanobacteria cells performing photosynthesis. At the same time, N2-fixation conferred an adaptive benefit to the filamentous morphology as cells could divide their labour into performing either N2-fixation or photosynthesis. This was followed by the culmination of complex multicellularity in the form of differentiated cells and patterned multicellularity.

scholarly journals Viruses and mobile elements as drivers of evolutionary transitions

2016 ◽  
Vol 371 (1701) ◽  
pp. 20150442 ◽  
Author(s):  
Eugene V. Koonin
Keyword(s):  
Genomic Analysis ◽  
Life Forms ◽  
Comparative Genomic ◽  
Biological Organization ◽  
Evolutionary Transitions ◽  
Selfish Genetic Elements ◽  
Cellular Life ◽  
History Of ◽  
Eusocial Animals ◽  
Multicellular Organisms

The history of life is punctuated by evolutionary transitions which engender emergence of new levels of biological organization that involves selection acting at increasingly complex ensembles of biological entities. Major evolutionary transitions include the origin of prokaryotic and then eukaryotic cells, multicellular organisms and eusocial animals. All or nearly all cellular life forms are hosts to diverse selfish genetic elements with various levels of autonomy including plasmids, transposons and viruses. I present evidence that, at least up to and including the origin of multicellularity, evolutionary transitions are driven by the coevolution of hosts with these genetic parasites along with sharing of ‘public goods’. Selfish elements drive evolutionary transitions at two distinct levels. First, mathematical modelling of evolutionary processes, such as evolution of primitive replicator populations or unicellular organisms, indicates that only increasing organizational complexity, e.g. emergence of multicellular aggregates, can prevent the collapse of the host–parasite system under the pressure of parasites. Second, comparative genomic analysis reveals numerous cases of recruitment of genes with essential functions in cellular life forms, including those that enable evolutionary transitions. This article is part of the themed issue ‘The major synthetic evolutionary transitions’.

scholarly journals Did Human Culture Emerge in a Cultural Evolutionary Transition in Individuality?

2021 ◽  
Author(s):  
Dinah R. Davison ◽  
Claes Andersson ◽  
Richard E. Michod ◽  
Steven L. Kuhn
Keyword(s):  
Hierarchical Organization ◽  
Evolutionary Transitions ◽  
Major Transitions ◽  
Social Communities ◽  
Human Culture ◽  
Eusocial Insects ◽  
The Social ◽  
History Of ◽  
Cultural Evolutionary ◽  
Multicellular Organisms

AbstractEvolutionary Transitions in Individuality (ETI) have been responsible for the major transitions in levels of selection and individuality in natural history, such as the origins of prokaryotic and eukaryotic cells, multicellular organisms, and eusocial insects. The integrated hierarchical organization of life thereby emerged as groups of individuals repeatedly evolved into new and more complex kinds of individuals. The Social Protocell Hypothesis (SPH) proposes that the integrated hierarchical organization of human culture can also be understood as the outcome of an ETI—one that produced a “cultural organism” (a “sociont”) from a substrate of socially learned traditions that were contained in growing and dividing social communities. The SPH predicts that a threshold degree of evolutionary individuality would have been achieved by 2.0–2.5 Mya, followed by an increasing degree of evolutionary individuality as the ETI unfolded. We here assess the SPH by applying a battery of criteria—developed to assess evolutionary individuality in biological units—to cultural units across the evolutionary history of Homo. We find an increasing agreement with these criteria, which buttresses the claim that an ETI occurred in the cultural realm.

scholarly journals Division of labor and fitness decoupling in evolutionary transitions in individuality

2020 ◽  
Author(s):  
Guilhem Doulcier ◽  
Katrin Hammerschmidt ◽  
Pierrick Bourrat
Keyword(s):  
Division Of Labor ◽  
Life History Traits ◽  
Linear Functions ◽  
Evolutionary Constraints ◽  
Evolutionary Transitions ◽  
Evolutionary Transitions In Individuality ◽  
Reproductive Division Of Labor ◽  
Multicellular Organisms ◽  
Reproductive Division

AbstractReproductive division of labor has been proposed to play a key role for evolutionary transitions in individuality (ETIs). This chapter provides a guide to a theoretical model that addresses the role of a tradeoff between life-history traits in selecting for a reproductive division of labor during the transition from unicellular to multicellular organisms. In particular, it focuses on the five keys assumptions of the model, namely (1) fitness is viability times fecundity; (2) collective traits are linear functions of their cellular counterparts; (3) there is a tradeoff between cell viability and fecundity; (4) cell contribution to the collective is optimal; and (5) there is an initial reproductive cost in large collectives. Thereafter the chapter contrasts two interpretations of the model in the context of ETIs. Originally, the model was interpreted as showing that during the transition to multicellularity the fitness of the lower-level (the cells) is “transferred” to the higher level (the collective). Despite its apparent intuitiveness, fitness transfer may obscure actual mechanisms in metaphorical language. Thus, an alternative and more conservative interpretation of the model that focuses on cell traits and the evolutionary constraints that links them is advocated. In addition, it allows for pursuing subsequent questions, such as the evolution of development.

scholarly journals Cooperation, clumping and the evolution of multicellularity

2015 ◽  
Vol 282 (1813) ◽  
pp. 20151075 ◽  
Author(s):  
Jay M. Biernaskie ◽  
Stuart A. West
Keyword(s):  
Public Goods ◽  
Public Good ◽  
Genetic Relatedness ◽  
Evolution Of Cooperation ◽  
Evolutionary Transitions ◽  
History Of ◽  
Major Shift ◽  
Multicellular Organisms ◽  
Number Of Cells

The evolution of multicellular organisms represents one of the major evolutionary transitions in the history of life. A potential advantage of forming multicellular clumps is that it provides an efficiency benefit to pre-existing cooperation, such as the production of extracellular ‘public goods’. However, this is complicated by the fact that cooperation could jointly evolve with clumping, and clumping could have multiple consequences for the evolution of cooperation. We model the evolution of clumping and a cooperative public good, showing that (i) when considered separately, both clumping and public goods production gradually increase with increasing genetic relatedness; (ii) in contrast, when the traits evolve jointly, a small increase in relatedness can lead to a major shift in evolutionary outcome—from a non-clumping state with low public goods production to a cooperative clumping state with high values of both traits; (iii) high relatedness makes it easier to get to the cooperative clumping state and (iv) clumping can be inhibited when it increases the number of cells that the benefits of cooperation must be shared with, but promoted when it increases relatedness between those cells. Overall, our results suggest that public goods sharing can facilitate the formation of well-integrated cooperative clumps as a first step in the evolution of multicellularity.

The Major Transitions in Evolution

1997 ◽  
Author(s):  
John Maynard Smith ◽  
Eors Szathmary
Keyword(s):  
Full Range ◽  
Evolution Of Cooperation ◽  
Major Transitions ◽  
Insect Societies ◽  
Wide Range ◽  
Major Transition ◽  
Life Itself ◽  
History Of ◽  
Emergence Of Cooperation ◽  
Multicellular Organisms

Over the history of life there have been several major changes in the way genetic information is organized and transmitted from one generation to the next. These transitions include the origin of life itself, the first eukaryotic cells, reproduction by sexual means, the appearance of multicellular plants and animals, the emergence of cooperation and of animal societies, and the unique language ability of humans. This ambitious book provides the first unified discussion of the full range of these transitions. The authors highlight the similarities between different transitions--between the union of replicating molecules to form chromosomes and of cells to form multicellular organisms, for example--and show how understanding one transition sheds light on others. They trace a common theme throughout the history of evolution: after a major transition some entities lose the ability to replicate independently, becoming able to reproduce only as part of a larger whole. The authors investigate this pattern and why selection between entities at a lower level does not disrupt selection at more complex levels. Their explanation encompasses a compelling theory of the evolution of cooperation at all levels of complexity. Engagingly written and filled with numerous illustrations, this book can be read with enjoyment by anyone with an undergraduate training in biology. It is ideal for advanced discussion groups on evolution and includes accessible discussions of a wide range of topics, from molecular biology and linguistics to insect societies.

The System is the Solution: Marx's Analysis of Capitalism

1986 ◽  
Vol 48 ◽  
pp. 13-13
Author(s):  
George Galster
Keyword(s):  
Production Process ◽  
Division Of Labor ◽  
Economic Base ◽  
Radical Theory ◽  
Labor Theory Of Value ◽  
Labor Theory ◽  
The Social ◽  
Theory Of Value ◽  
Relationship Of ◽  
Pedagogic Device

The following note describes a skit designed primarily as a pedagogic device to illustrate in a meaningful (and, hopefully, provocative and humorous) way Marx's analysis of capitalism. Numerous concepts and phenomena are “brought to life” in the skit: exploitation, immiseration and alienation of workers, maintenance wage, labor theory of value, mechanization and the division of labor, systemic tendencies toward economic crises, relationship of various superstructural components (welfare, religion, etc.) to the economic base, and the radical theory of the state. More specifically, the economic base of a hypothetical capitalist society consists of a stylized production process involving “resources” (Oreo cookies), “labor” (students selected from the class) and eventually “capital” (table knives). The ability of the monopoly capitalist to accumulate surplus by exploiting workers becomes manifest. Other elements of the social superstructure (unions, government, religion, etc.)

Burney's The Wanderer and Early-Nineteenth-Century Commodity Fetishism

2002 ◽  
Vol 57 (1) ◽  
pp. 1-30 ◽  
Author(s):  
Andrea Henderson
Keyword(s):  
Nineteenth Century ◽  
French Revolution ◽  
Social Changes ◽  
Commodity Fetishism ◽  
Early Nineteenth Century ◽  
Labor Theory ◽  
History Of ◽  
Theory Of Value ◽  
Historical Moment ◽  
The Wanderer

This essay explores a particular moment in the history of commodity fetishism by means of an examination of Frances Burney's The Wanderer (1814). The novel, which is explicitly concerned with the social changes facing early-nineteenth-century England, reveals that at this historical moment the commodity inspired emotions of a particular kind: it was idealized and perceived as attractively individualized, aloof, exotic, and changeable, and it elicited a passionate and sometimes even painful form of desire. In The Wanderer Burney explores the human repercussions of this new way of engaging with objects in the marketplace. She reveals, moreover, the extent to which the fetishism of the commodity reflected not just developments within the economy but also political change: under the influence of the French Revolution the charisma once generated by social status was transferred to the economic realm, where, embodied in the commodity, it gave rise to a pleasurable but masochistic reverence. Burney'sargument for the usefulness of economic independence necessarily leads her to appreciate the commodity fetishism she describes: even while she develops a labor theory of value, Burney promotes a mystification of the commodity by insisting on the aloof independence of both labor and its products. Thus, Burney uses the apparent autonomy of things——which Marx decries——as a means to argue for the autonomy of the makers of those things.

The world’s repository at 75: a history of the United Nations Archives*

Comma ◽  
2021 ◽  
Vol 2019 (2) ◽  
pp. 19-36
Author(s):  
Aleksandr Gelfand
Keyword(s):  
United Nations ◽  
San Francisco ◽  
International Organization ◽  
Records Management ◽  
Significant Events ◽  
The World ◽  
History Of ◽  
The United Nations ◽  
Administrative Structures

Seventy-five years ago (1945), the United Nations (UN) was founded in San Francisco by 50 nations. There, a small archives unit served to assemble the first records of the organization; this was the first iteration of today’s Archives and Records Management Section (ARMS). Throughout its history, the fortunes of the UN Archives have waxed and waned, while its role has continuously evolved. Trying to carve out a place for itself within the largest international organization in the world, its physical and administrative structures have undergone profound changes, as has its mission, number of staff, the type of records it holds and its users. This paper examines significant events in the development of the UN Archives, the challenges it has faced and what may be learned from them.

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