Stem arthropods
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Stem Arthropods. Anomalocaris. Opabinia. Hurdia. Erwin and Valentine, The Construction of Animal Biodiversity, 2013. Erwin and Valentine, The Construction of Animal Biodiversity, 2013. Genomic Complexity. (Erwin, 2009; Erwin & Valentine 2013). Erwin et al. 2011, Science.

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Stem Arthropods

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Stem Arthropods

Anomalocaris

Opabinia

Hurdia


Erwin and Valentine, The Construction of Animal Biodiversity, 2013


Erwin and Valentine, The Construction of Animal Biodiversity, 2013


Genomic Complexity

(Erwin, 2009; Erwin & Valentine 2013)


Erwin et al. 2011, Science


Strongylocentrotus


Sea Urchin dGRN

Biotapestry.org


Sea Urchin endomesoderm GRN


Gene Regulatory Network Structure

Erwin and Valentine, Forthcoming, 2012; after Davidson


Davidson & Erwin, 2009


Increase in miRNA families; complexity

of dGRN interactions

Origin of Developmental

Toolkit

Origin of Eumetazoa

Most signalling

pathways

present


Fedonkin et al The Rise of Animals, 2007


Erwin and Valentine, Forthcoming, 2012


Ecosystem Engineering

Species 2

Species 1

Natural selection

Natural selection

Et

Gene pool

Gene pool

Ecological

Spillover

Ecological inheritance

Genetic inheritance

Genetic inheritance

Natural selection

Natural selection

Et+1

Gene pool

Gene pool

Ecological

Spillover


Cambrian Ecosystem Engineering

  • Archaeocyathid reefs (+)

  • Sponges & other filter feeders (+)

  • Burrowed sediments (+/-)

  • Shelly substrates (+)

  • Mesoozooplankton(+)


Ecological Spillovers

  • Sponges: sequestering carbon via filtration. Oxidation of oceans allow increased production of collagen.

  • Burrowing: change in S isotopes, enhances primary productivity in seds, increases biodiversity


P & P Definitions

  • Innovation “improve on existing ways of doing things” (which sounds to a biologist like adaptation)

  • Inventions “change the ways things are done”


Invention & Innovation

  • Invention is the creation of something new and distinct (contrast with variation on established themes)

  • Innovation occurs when inventions become economically or ecologically significant

Joseph

Schumpeter

(1883-1950


Increase in miRNA families; complexity

of dGRN interactions

Origin of Developmental

Toolkit

Origin of Eumetazoa

Most signalling

pathways

present


Defining Novelty

  • Are ‘novelty’ and ‘innovation’ synonymous?

  • Character based: new construction elements of a body plan (not homologous to pre-existing structure)

  • Process based: novelty should involve a transition between adaptive peaks and a breakdown of ancestral developmental constraints so that new sorts of variation are generated (Halgrimsson et a. 2012 J. Exp. Zool)


  • Evolutionary novelty originates when part of the body acquires individuality and quasi-independence

  • Involves origin of new character identity rather than character state (homology)


How are new evolutionary spaces created?

  • Potentiated by broader environmental setting (physical, genetic, ecologic)

  • Actualized by genetic and developmental innovations leading to a new clade

  • Refined by further developmental and ecological changes

  • Realized as innovations by ecological expansion and evolutionary success


Mechanisms of Organizational Genesis

  • Transposition and refunctionality (var)

  • Anchoring diversity (ecology)

  • Incorporation and detachment (var)

  • Migration and homology (niche const)

  • Conflict displacement/dual inclusion (ETI)

  • Purge and mass mobilization (ecology)

  • Privatization and Business groups (ecol/ETI)

  • Robust action and multivocality (?)


Nature of Contingency

  • Sampling error

  • Unpredictability of the course of history

  • Sensitivity to initial conditions (Beatty 2006)

  • Sensitivity to external disturbance

  • Macroevolutionary stochasticity


Nature of Contingency

  • Sampling error

  • Unpredictability of the course of history

  • Sensitivity to initial conditions (Beatty 2006)

  • Sensitivity to external disturbance

  • Macroevolutionary stochasticity

    And does the ‘topography’ of historical contingency change over time?


Modern Synthesis

  • Transmission Genetics

  • Simple path from genotype to phenotype

  • Primacy of genetic inheritance

  • Selection within populations as primary driver of evolution

  • Opportunistic

  • Uniformitarian


Emerging Perspectives

  • No simple mapping from genotype to phenotype (evo-devo)

  • Multiple forms of inheritance

  • Multiple levels of selection

  • Important roles for mutation and drift in addition to selection

  • Macroevolutionary lags

  • Non-uniformitarian


Search Vs Construction

  • Innovation is often described as search through a space of “the adjacent possible” (Kaufmann, Wagner)


Grassland Evolution


Grass Phylogeny

Kellogg, 2001, Plant Physiology


Macroevolutionary Lags


How are new evolutionary spaces created?

  • Potentiated by broader environmental setting (physical, genetic, ecologic)


How are new evolutionary spaces created?

  • Potentiated by broader environmental setting (physical, genetic, ecologic)

  • Actualized by genetic and developmental innovations leading to a new clade


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