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Evolutionary Theory: A Hierarchical Perspective

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Eldredge N, Pievani T, Serrelli E, Tëmkin I, eds. (2016). Evolutionary Theory: A Hierarchical Perspective. Chicago: University of Chicago Press.

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Dia da evolução em Lisboa

A Evolução diz respeito a todos nós. Em algum momento das nossas vidas, todos nós já nos perguntámos de onde viemos e qual a origem das espécies que nos rodeiam. Como evoluíram os seres humanos? Como surgiram as plantas que estão no nosso jardim? Será que um traço unicamente humano como a linguagem evolui? E por que razão algumas espécies se extinguem, enquanto outras prosperam? Na verdade, como é que a vida de facto evoluiu?
Durante o Dia da Evolução em Lisboa, vamos reunir um conjunto de especialistas nacionais e internacionais que tentarão responder a algumas destas questões, tanto a si como aos seus filhos, numa linguagem simples e acessível.


16.00 Abertura
Rosalia Vargas, Presidente da Ciência Viva
Nathalie Gontier, Directora do Lisbon Applied Evolutionary Epistemology Lab

16.30 Evolução, um panorama geral, e Evolução, vista de perto
Folmer Bokma, O que Podem as Espécies Actuais Dizer-nos Sobre as já Extintas?
Douglas Zook, A Dominância da Simbiose na Biosfera

17.00 A Evolução Humana
Emanuele Serrelli, Ecologia, Biogeografia e Descendência nos Modelos Recentes de Evolução Humana
Larissa Mendoza, O papel da Arte Visual na Evolução Humana

17.30 Intervalo

18.00 A Evolução da Linguagem Humana
Daniel Dor, A Co-evolução da Linguagem e dos seus Falantes
Mónica Tamariz, Como o Computador nos Ajuda a Compreender a Evolução da Linguagem

18.30 Perguntas e Debate
19.00 Fim

Organized by AppEEL

Look for it in the Talks page (with additional links):

2013, Mar 16 (h.4 PM) – Dia da evolução em Lisboa, Cîencia Viva Knowledge Pavillion, Lisboa, Portugal: Ecologia, Biogeografia e Descendência nos Modelos Recentes de Evolução Humana [Sloshing in the bucket: Ecology, Biogeography, and descent in recent Models of Human Evolution]. With Folmer Bokma, Douglas Zook, Larissa Mendoza, Daniel Dor, Mónica Tamariz. Conference.



Evolutionary explanation and bucket thinking

sloshing bucket evolutionary explanationThe hierarchical interplay between ecology and genealogy is a fundamental ingredient for the most compelling current explanations in evolutionary biology. Yet philosophy of biology has hardly welcomed a classic fundamental intuition by palaeontologist Niles Eldredge, i.e. the non-coincidence and interrelation between ecology and genealogy, and their interaction in a Sloshing Bucket fashion. Hierarchy Theory and the Sloshing Bucket need to be made precise, developed and updated in light of an explosion of new discoveries and fields and philosophical issues. They also suggests re-thinking concepts such as natural selection, species, and speciation that have always been part of evolutionary theory.

contrastes coverWhen philosophers, theorists, and working scientists think about evolution, they often do so by means of models based on inheritance. Natural selection, for example, is quantified as selective pressures, intended as coefficients directly influencing reproductive outputs, or summaries of the influences on reproductive outputs. Ecology therein is often seen as the circumstancy of evolution, a source of perturbations and influences which is accurately reflected, translated into units of reproductive output. Yet contemporary explanatory models of biological evolution, for example those that are emerging for Homo sapiens, show that a much much better understanding of the constructive interaction between two independent domains – the ecological and the genealogical – is required not only to account for quintessentially macroevolutionary events such as mass extinctions, but also for smaller-scale happenings such as speciations and intra-specific evolutionary innovations. The huge frequency of utterly inheritance-centric philosophical works on natural selection seems, in this light, an unmistakable symptom of theoretical inertia. Bucket Thinking could reflect the way in which the best evolutionary explanations are built today, and at the same time aid the explanation by laying down and relating the researches that are being conducted in different fields (e.g. from population genetics to palaeontology, from ecosystem ecology to developmental biology). Bucket Thinking is also a way of reframing many classical problems, such as multi-level selection, individuality, or even reductionism or emergence. This doesn’t mean that Hierarchy and the Bucket are free of their own epistemological and methodological problems. On the contrary, what we suggest is precisely a critical philosophical discussion more deep than the one that has been deserved until now to these potentially fruitful ideas. Hierarchy Theory asks to be developed and updated in light of an explosion of new discoveries and fields, e.g., EvoDevo, lateral gene transfer and the charge of zoo-centrism pending on evolutionary theory (O’Malley 2010), network theory, genomics. But the dual Hierarchy Theory is also a way of re-thinking and re-framing concepts that have ever been present in evolutionary theory, like natural selection itself, or species and speciation, as we have seen here.

Look for it in the Publications page (with additional links):

Pievani T, Serrelli E (2013). Bucket thinking: the future framework for evolutionary explanation. Contrastes. Revista internacional de filosofia – Suplementos 18: 389-405. ISSN 1139-9922 [http://hdl.handle.net/10281/44944]

The hierarchy theory view of speciation

Hierarchy theory (e.g. Salthe 1985, Eldredge 1986) provides a unifying approach for representing the multi-level structure of the organic world and an explanatory framework for the wide range of natural phenomena. Its birthdate can be located in the 1980s, when evolutionary biologists began exploring in detail the nature of hierarchical systems as an approach to understanding both the nature of these complex systems, and the nature of their interactions that underlie the evolutionary process. Nowadays hierarchy theory is being developed and updated in light of an explosion of new discoveries and fields, but also as a way of re-thinking and re-framing concepts, like speciation, that have been present in evolutionary theory for many decades.
According to hierarchy theory, organisms are parts of at least two different kinds of systems:
(1) matter-energy transfer systems, where organisms are parts of local populations that in turn are parts of local ecosystems. The economic roles played by such populations are what constitute ecological niches. Local ecosystems are parts of regional systems, a geographic mosaic of matter-energy transfer systems that together constitute the global biosphere.
(2) genetically-based information systems: organisms are parts of local breeding populations that in turn are parts of each individual species. Species, through the process of evolution, are parts of historical lineages: genera, then families, orders etc. of the Linnaean Hierarchy. While evolutionary theory has legitimately focused most on genetic processes and the formation of genetic lineages, evolution does not occur in a vacuum: specifically, it is what takes place inside matter-energy transfer systems that determines, in large measure, the patterns of stability and change in genetic systems that we call “evolution”.
The “sloshing bucket theory of evolution” (Eldredge 2003) is an example of how theoretical hierarchy theory applies to the real world of biological systems and their histories. The theory describes the multilevel interplay between ecological disruption, taxic extinction and consequent bursts of evolutionary diversification. The pulse, pace and scope of ecological disruptions – ranging from localized disturbances; regional, longer term disruptions; and (rarely) drastic global environmental change – have corresponding effects on dynamic matter-energy systems on different scales. Localized disruptions result in re-establishment of very similar local ecosystems, based on genetic recruitment of members of the same species still living outside the affected area; on the grandest scale, mass extinctions resulting from global environmental disruption witness the disappearance of larger-scale taxonomic entities. Over periods of millions of years (5-10 my, typically), the ecological roles played in the now-disrupted ecosystems by organisms in now-extinct groups are assumed by evolutionarily modified species that are derived from taxa that survived the extinction event. The intermediate situation – where regional ecosystems are disturbed, resulting in the extinction of many species – is perhaps of the greatest interest: the fossil record shows clearly that most speciation events (hence most evolutionary genetic change in the history of life) take place as a consequence of regional ecosystemic collapse and multiple extinctions of species across different lineages.
Traditional presentations of speciation commonly depict one species at a time, and classify speciation events on a geographical basis (allopatric, peripatric, sympatric etc.). In light of hierarchy theory, both these habits are wrong, and a rethinking the process of speciation is needed to explicitly describe the interaction between (1) economic and (2) genealogical events.
First, with “geographic speciation”, more than an eco-geographical event we actually mean one of the possible genealogical consequences of ecological barriers, i.e. the multiplication of genealogical entities at the level of species within instances of the evolutionary hierarchy (we use the biological concept of species, with no necessary link with the individuality thesis). As Gavrilets (2010) pointed out, a geographical taxonomy of speciation is silent about what happens in the genealogical hierarchy, for example about the kinds of genetic, morphological or behavioral “uncoordination” that yield reproductive isolation. A new taxonomy of processes of genealogical diversification (e.g., sympatric speciation, birth of varieties and subspecies, agamospecies) is possible. On the other hand, geographic barriers impact many species at once: ecological events which arguably trigger speciation are cross-phyletic.
Second, a proper re-description of geographic speciation should contextualize the phenomenon properly in the scenario of ecological systems (ecosystems and, at a macroevolutionary time scale, faunas). Sometimes speciation can be adaptive (a critical assessment of its relative frequency would be necessary). But the important thing is that adaptation – usually seen from an intra-populational point of view – should as well be described in the context of ecological reassortment and reshaping of communities. We are in presence of contemporaneous processes that occur at the population-ecological time scale at different levels of the ecological hierarchy, inviting reinterpretation of the concepts of adaptation and fitness, coevolution, and niche construction. Intra-populational, inter-individual variation of ecologically relevant traits is examined as the “raw recruit” for natural selection. Transversal comparison among ecological communities brings into focus patterns in ecological processes and systems, and also processes like adaptive convergence. In this way, some epistemological problems which are usually related to adaptation disappear, and new ways of framing the issue emerge. For example, coevolution is not a separate issue, neither it is niche construction, i.e., the cross-genealogical modification of selective pressures as a consequence of the existence and activity of populations, including the interactive role of abiotic factors.
It is important to remark that this re-worked speciation concepts seems to play a key role in the most updated views on hominid evolution.

Gavrilets S (2010). High-dimensional fitness landscapes and speciation. In Pigliucci M, Müller GB, eds. Evolution – The Extended Synthesis. Cambridge-London: MIT Press, pp. 45-79.
Eldredge, N. (1986), “Information, Economics, and Evolution,” Annual Review of Ecology and Systematics, 17, 351-369.
Eldredge, N. (2003), “The Sloshing Bucket: How the Physical Realm Controls Evolution,” in Evolutionary Dynamics – Exploring the Interplay of Selection, Accident, Neutrality, and Function, eds. J. P. Crutchfield and P. Schuster, Oxford: Oxford University Press, pp. 3-32.
Salthe, S. N. (1985), Evolving Hierarchical Systems: Their Structure and Representation, New York: Columbia University Press.

Look for it in the Publications page (with additional links):

Pievani T, Serrelli E (2012). From molecules to ecology and back: the hierarchy theory view of speciation. In Antonio Diéguez, Vicente Claramonte, Jesús Alcolea, Gustavo Caponi, Arantza Etxeberría, Pablo Lorenzano, Alfredo Marcos, Jorge Martínez-Contreras, Alejandro Rosas, eds. I Congreso de la Asociación Iberoamericana de Filosofía de la Biología, Publicacions de la Universitat de València, pp. 296-302. ISBN 978-84-370-9040-5 [http://hdl.handle.net/10281/39798]


Criticizing adaptive landscapes, ecology and genealogy

Disentangling ecological vs. genealogical dimensions is a core task of hierarchy theory in evolutionary biology. As Eldredge repeatedly epitomized, organisms carry out (only) two distinct kinds of activities: they survive, and they reproduce.
At the organismal level, the organism stays the same whether we consider it ecologically or genealogically – yet, differences can occur in what features we consider relevant, and what fitness measurement we use.
At higher levels, the two dimensions diverge, realizing different systems. Reproductive (deme) may not coincide with ecological (avatar) population. Further upwards, along the ecological dimension, higher-level systems are grouped by energy- matter interconnection, whereas, along the genealogical dimension, higher taxa are assembled by relatedness.
In Dobzhansky’s (1937) use of the adaptive landscape visualization (Wright 1932), all living species are imagined as distributed on adaptive peaks which correspond to ecological niches in existing environments. Peaks are grouped forming genera and higher taxa (e.g., “feline”, “carnivore” ranges), and geographic speciation is figured out – like adaptation – as movement on the landscape.
In criticizing Dobzhansky’s landscape, Eldredge wrote that species actually do not occupy ecological niches; demes don’t, either; avatars do.
I point out that neighborhood and movement need to be conceived separately in genealogical and ecological spaces. Indeed, ecology should be further split in at least two spaces: geographic and phenotypic/adaptive. Movement in one space may in fact result in stability in the other(s).
I also comment on the adaptive landscape: technical limitations prevent it from being coherently used above the population level, even though as a metaphor. Finally, I emphasize the partiality of any landscape – based on the choice of relevant features and fitness components – and interpret partiality as the way of approaching complex multi- hierarchical structure in evolution.

Emanuele is also organizer of the “Hierarchy theory” session at the conference.

Look for it in the Publications page (with additional links):

Serrelli E (2011). Criticizing adaptive landscapes and the conflation between ecology and genealogy. Meeting of the International Society for History, Philosophy, and Social Studies of Biology (ISHPSSB), Salt Lake City (Utah, USA), July 10-16. [http://hdl.handle.net/10281/28191]


Hierarchy Theory in Salt Lake City

In 2010 Emanuele Serrelli co-organized the session “Hierarchy Theory of Evolution” inviting Niles Eldredge and 10 other scholars on Hierarchy Theory at the International Society for the History, Philosophy, and Social Studies of Biology Sunday, July 10, 2011 ‐ Friday, July 15, 2011, University of Utah Salt Lake City, Utah United States. Hierarchy Theory assumes that the evolutionary disciplines have an ontological basis for their existence, i.e. systems with peculiar spatiotemporal dimensions, origins, histories, demises, and internal dynamics leading to stability and change through time. The theory is developing around Eldredge’s recognition of at least two main distinct evolutionary hierarchies – the genealogical and the ecological – and around a general vision of evolution as a process of interactions at various scales. E.g., macro-evolutionary patterns are explained by a “sloshing bucket” model, where ecological events reverberate in the evolutionary hierarchy.


  • BROOKS, Dan – Metaphors for the Extended Synthesis: Something Old, Something New.
  • CAIANIELLO, Silvia – Modularity and Hierarchy Theory.
  • CAPORAEL, Linnda – Grounding Human Social Cognition in Hierarchical Group Structure.


  • DIETL, Gregory – Toward a Unified Ecology in Macroevolution.
  • ELDREDGE, Niles – A Matter of Individuality: Hierarchy Theory at the Dawn of Evolutionary Biology.
  • MILLER, William – Macroevolutionary Consonance and expansion of the Modern Synthesis.


See full session abstracts on Academia.


The Ecology of Evolution

Serrelli E (2003). L’ecologia dell’evoluzione: il pluralismo evolutivo letto attraverso un caso di radiazione adattativa. Master Degree Dissertation in Educational Sciences, University of Milano Bicocca, Milan, Italy. [DOI 10.13140/2.1.3863.5525]


This is an epistemological research, concerning knowledge processes. The choice of African Cichlids as a subject has been stimulated mainly by the fact that these fishes are targeted by remarkably different observers: fishermen, ecologists, biologists, geneticists, evolutionists with different approaches, hobbyists and aquarists – beginners and experts. The great epistemological interest of this crowd of observers lies not only in the comparison of different knowing processes applied to the same object, but also in their multiple and complex reciprocal interactions…