Research ArticleEVOLUTIONARY BIOLOGY

How colonial animals evolve

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Science Advances  08 Jan 2020:
Vol. 6, no. 2, eaaw9530
DOI: 10.1126/sciadv.aaw9530
  • Fig. 1 A Stylopoma colony grows by adding modules and the population of Sylopoma colonies increase by the settling of sexually produced larvae.

    Modules proliferate by asexual clonal budding. The growth of a single colony is illustrated in this series along with the numeric increase in the number of colonies. New colonies are founded from sexually derived larvae that disperse from a mother colony. The first sexually derived ancestral set of zooids is shown in the top left. Time runs from top to bottom so that by the end of this series, this colony has expanded markedly from the clonal proliferation of its modules, and the populations of colonies have also expanded from the sexual production of offspring colonies.

  • Fig. 2 We measure the evolutionary potential of these twelve traits.

    Module-level traits are expressed by single modules. These traits are quantitative measures, lengths, widths, and densities. Colony-level traits are expressed by multiple modules and are measures of their relative positions, orientations, and numbers of modules. See the Supplementary Materials for a full description of these traits.

  • Fig. 3 The evolutionary potential for eight modular and four colony-level traits in two species of the bryozoan Stylopoma.

    The parent-offspring phenotypic covariance for each trait is shown in columns. We calculate the heritability of member-level traits within each colony (indicated by gray circles jittered horizontally to avoid plotting overlap). The median heritability across colonies is shown by the large red circles. For colony-level traits, only a single estimate of heritability is possible; thus, the dispersion around the heritability estimate is indicated by vertical bars. Colony traits without bars do not vary among colonies.

  • Fig. 4 Map indicating the location of the Smithsonian San Blas field station in Panamá.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/6/2/eaaw9530/DC1

    Supplementary Materials and Methods

    Fig. S1. A small Stylopoma colony consisting of many thousands of members.

    Fig. S2. A closeup of a Stylopoma colony showing a clonal lineage of autozooids.

    Fig. S3. Polymorphic zooids of Stylopoma.

    Fig. S4. A closeup of a Stylopoma colony consisting autozooids, three types of avicularia, and an ovicell.

    Fig. S5. Evolutionary potential as measured by the heritability of traits between parent and offspring zooids.

    Fig. S6. Evolutionary potential as measured by the heritability of traits between parent and offspring colonies.

    Table S1. Zooid measurements of maternal Stylopoma colonies.

    Table S2. Zooid measurements of offspring Stylopoma colonies.

    References (5264)

  • Supplementary Materials

    The PDFset includes:

    • Supplementary Materials and Methods
    • Fig. S1. A small Stylopoma colony consisting of many thousands of members.
    • Fig. S2. A closeup of a Stylopoma colony showing a clonal lineage of autozooids.
    • Fig. S3. Polymorphic zooids of Stylopoma.
    • Fig. S4. A closeup of a Stylopoma colony consisting autozooids, three types of avicularia, and an ovicell.
    • Fig. S5. Evolutionary potential as measured by the heritability of traits between parent and offspring zooids.
    • Fig. S6. Evolutionary potential as measured by the heritability of traits between parent and offspring colonies.
    • References (5264)

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    Other Supplementary Material for this manuscript includes the following:

    • Table S1 (Microsoft Excel format). Zooid measurements of maternal Stylopoma colonies.
    • Table S2 (Microsoft Excel format). Zooid measurements of offspring Stylopoma colonies.

    Files in this Data Supplement:

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