Philosophical foundations for the hierarchy of life

  title={Philosophical foundations for the hierarchy of life},
  author={Deborah E. Shelton and Richard E. Michod},
  journal={Biology \& Philosophy},
We review Evolution and the Levels of Selection by Samir Okasha. This important book provides a cohesive philosophical framework for understanding levels-of-selections problems in biology. Concerning evolutionary transitions, Okasha proposes that three stages characterize the shift from a lower level of selection to a higher one. We discuss the application of Okasha’s three-stage concept to the evolutionary transition from unicellularity to multicellularity in the volvocine green algae. Okasha… 

Toward major evolutionary transitions theory 2.0

  • E. Szathmáry
  • Biology
    Proceedings of the National Academy of Sciences
  • 2015
The impressive body of work on the major evolutionary transitions in the last 20 y calls for a reconstruction of the theory although a 2D account (evolution of informational systems and transitions

Evolution of Individuality: A Case Study in the Volvocine Green Algae

It is found that the fulfillment of some criteria, such as genetic homogeneity and genetic uniqueness, do not change across species, while traits underpinning other aspects of individuality, including degrees of integration, group-level fitness and adaptation, and group indivisibility, change dramatically.

Division of labour in microorganisms: an evolutionary perspective.

The set of conditions that define division of labour are explored and it is proposed that cooperation between different phenotypes is a defining feature of division of labourers.

Beyond Fitness Decoupling: Tradeoff-breaking during Evolutionary Transitions in Individuality

It is shown that while early stages of transitions might often involve tradeoffs among particle traits, later—and critical—stages are likely to involve rupture of such tradeoffs, and Tradeoff-breaking thus stands as a useful marker for ETIs.

Tradeoff breaking as a model of evolutionary transitions in individuality and limits of the fitness-decoupling metaphor

It is shown that fitness of particles and collectives can never decouple because calculations of fitness performed over appropriate and equivalent time intervals are necessarily the same provided the population reaches a stable collective size distribution.

Kin and multilevel selection in social evolution: a never-ending controversy?

It is argued that the two theories can offer complementary approaches to the study of social evolution: kin selection approaches usually focuses on the identification of optimal phenotypes and thus on the endresult of a selection process, whereas multilevel selection approaches focus on the ongoing selection process itself.

Trait heritability in major transitions

Rather than being an impediment to major transitions, it is shown that, under a wide range of conditions, the heritability of collective-level traits is actually higher than that of the corresponding particle- level traits.

The evolution of social life in family groups

It is inferred that the explicit consideration of thus far neglected facets of family life, together with their study across the whole diversity of family systems, are crucial to advance the understanding of the processes that shape the evolution of social life.

The other facets of family life and their role in the evolution of animal sociality

  • J. KramerJ. Meunier
  • Biology, Psychology
    Biological reviews of the Cambridge Philosophical Society
  • 2018
It is inferred that the explicit consideration of thus‐far neglected facets of family life, together with their study across the whole diversity of family systems, are crucial to advance the understanding of the processes that shape the evolution of social life.

Mitosis circumscribes individuals; sex creates new individuals

For eukaryotes, meiosis and karyogamy provide a consistent way to demarcate individuals and generations and Mitotic heritability circumscribes an individual, whereas meiotic heritability demarcates new individuals and Generations.



The Units of Evolutionary Transition

The amended analysis suggests a new unit of evolution, the ireproducer,i which generalizes the concept of a replicator, and the theory of evolutionary transition, the evolutionary origin of new levels of biological organization, is revised.

Evolution of Complexity in the Volvocine Algae: Transitions in Individuality Through Darwin's Eye

This work uses phylogenetic reconstructions of ancestral character states to trace the evolution of steps involved in this transition in volvocine algae, and inferred changes can be understood as components of cooperation-conflict–conflict mediation cycles as predicted by multilevel selection theory.

The Major Transitions in Evolution

This book discusses the origins of societies, development and evolution, and the development of spatial patterns in simple organisms.

The units of selection.

Cases in which selection acts simultaneously at two levels above the species level, and in the major transitions in evolution, entities that were capable of independent replication before the transition can only replicate as part of a larger whole after it are concerned.

A twelve-step program for evolving multicellularity and a division of labor.

  • D. Kirk
  • Biology
    BioEssays : news and reviews in molecular, cellular and developmental biology
  • 2005
Twelve important ways are outlined in which the developmental repertoire of an ancestral unicell similar to modern C. reinhardtii was modified to produce first a small colonial organism like Gonium that was capable of swimming directionally, then a sequence of larger organisms in which there was an increasing tendency to differentiate two cell types, and eventually Volvox carteri with its complete germ-soma division of labor.

The minor transitions in hierarchical evolution and the question of a directional bias

It is argued that the existence of a bias in hierarchical organization is an open empirical question, and it is shown how testing is possible.

Triassic origin and early radiation of multicellular volvocine algae

Estimating divergence times using a multigene data set with multiple fossil calibrations and using these estimates to infer the times of developmental changes relevant to the evolution of multicellularity show that Volvox diverged from unicellular ancestors at least 200 million years ago.


  • D. McShea
  • Biology
    Evolution; international journal of organic evolution
  • 1996
A scheme for understanding complexity is proposed that provides a conceptual basis for objective measurement and shows complexity to be a broad term covering four independent types.

Group Selection

George C. Williams has here collected the work of the chief partisans with opposed viewpoints on the theory of selection at the group level to state their arguments and rebuttals, and the reader is exposed to all sides of the dispute.

Alternative formulations of multilevel selection

It is argued that the “effect hypothesis” of macroevolution, requiring, in selection among species, both the absence of group effects on organismic fitness (multilevel selection) and the direct determination of species fitnesses by those of organisms, is untestable with paleontological data.