Skip to content

Research at St Andrews

Hierarchical (mm- to km-scale) environmental variation affecting skeletal phenotype of a marine invertebrate (Electra pilosa, Bryozoa): Implications for fossil species concepts

Research output: Contribution to journalArticle


A comparative record of morphological change of fossil specimens through geologic time can provide insights into the rates and patterns of microevolution and speciation. However, questions concerning the extent to which environmental conditions influence skeletal morphology, and potentially confound recognition of genetic change, can be most meaningfully addressed with living taxa. The marine encrusting blyozoan, Electra pilosa (L), was used to assess the magnitude of environmental effects on zooecium-level skeletal morphology at different spatial scales. The latter included environmental effects or factors ranging in level from (1) micro-environmental (variation within and among immediately adjacent colonies), (2) meso-environmental (small-scale colony positional effects among colonies within a common habitat), and (3) macro-environmental (morphological variation among colonies from recognizably different environmental settings).

Macro-environmental influence on zooecial morphology for colonies among localities (10 km-scale) can be detected by comparison of colonies from wave-protected/tidal-dominated versus open coast/wave-dominated settings, and this accounted for similar to 75% of the observed morphological variation. Meso-environmental variation that is, small-scale (10(1) to 10(2) m) systematic (nonrandom) differences that would go undetected in a geologic setting - had a minimal deterministic influence on zooecial morphology, and accounted for similar to 2.5% of observed variation.

Variation among colonies from the same site was highly significant. Much of this morphologic variation (similar to 30%) is attributable to genotypic variation among colonies, but micro-environmental sources cannot be excluded (10(1) to 10(2) cm-scale). Variation within colonies, accounting for similar to 60% of the observed morphological variation, can be further partitioned into Micro-environmental differences, similar to 40% (10(1) to 10(2) mm-scale) associated with spatiotemporal position, and the Life History of individual modules (similar to 20%). Environmental levels (factors) that are associated with significant morphological effects can also be recognized by their sedimentological properties, which can be preserved in the geologic record. Thus, results from this and similar studies have relevance for and can potentially be directly applied to studies of fossil organisms.


Original languageEnglish
Pages (from-to)213-226
Number of pages14
JournalPalaeogeography, Palaeoclimatology, Palaeoecology
Early online date25 Jan 2014
Publication statusPublished - 15 Feb 2014

    Research areas

  • Life-history, Zooid size, Cheilostome bryozoans, Paleozoic bryozoan, Food concentration, Colony growth, Evolution, Flow, Population, Settlement

Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by author

  1. Variation in post-smolt growth pattern of wild one sea-winter salmon (Salmo salar L.), and its linkage to surface warming in the eastern North Atlantic Ocean

    Todd, C. D., Hanson, N. N., Boehme, L., Revie, C. W. & Marques, A. R., 21 Oct 2020, In : Journal of Fish Biology. Early View, 11 p.

    Research output: Contribution to journalArticle

  2. Precision and accuracy of Dahl-Lea back-calculated smolt lengths from adult scales of Atlantic salmon (Salmo salar L.)

    Hanson, N. N., Smith, G. W., Middlemas, S. J. & Todd, C. D., 29 Jan 2019, In : Journal of Fish Biology. 94, 1, p. 183-186

    Research output: Contribution to journalArticle

  3. Context-dependent reduction in somatic condition of wild Atlantic salmon infested with sea lice

    Susdorf, R., Salama, N., Todd, C. D., Hillman, R., Elsmere, P. & Lusseau, D., 15 Nov 2018, In : Marine Ecology Progress Series. 606, p. 91-104

    Research output: Contribution to journalArticle

  4. Mate limitation in sea lice infesting wild salmon hosts: the influence of parasite sex ratio and aggregation

    Cox, R., Groner, M., Todd, C. D., Gettinby, G., Patanasatienkul, P. & Revie, C., Dec 2017, In : Ecosphere. 8, 12, 19 p., e02040.

    Research output: Contribution to journalArticle

  5. Marine life of the sea trout

    Thorstad, E. B., Todd, C. D., Uglem, I., Bjørn, P. A., Gargan, P. G., Vollset, K. W., Halttunen, E., Kålås, S., Berg, M. & Finstad, B., Mar 2016, In : Marine Biology. 163, 3, 19 p., 47.

    Research output: Contribution to journalArticle

Related by journal

  1. Palaeogeography, Palaeoclimatology, Palaeoecology (Journal)

    Michael Ian Bird (Member of editorial board)

    2006 → …

    Activity: Publication peer-review and editorial work typesEditor of research journal

Related by journal

  1. Convergent continental margin volcanic source for ash beds at the Permian-Triassic boundary, South China: constraints from trace elements and Hf-isotopes

    Wang, X., Cawood, P. A., Zhao, L., Chen, Z-Q., Lyu, Z. & Ma, B., 1 Apr 2019, In : Palaeogeography, Palaeoclimatology, Palaeoecology. 519, p. 154-165

    Research output: Contribution to journalArticle

  2. Palynology and micropalaeontology of the Pliocene - Pleistocene transition in outcrop from the western Caspian Sea, Azerbaijan: potential links with the Mediterranean, Black Sea and the Arctic Ocean?

    Richards, K., van Baak, C. G. C., Athersuch, J., Hoyle, T. M., Stoica, M., Austin, W. E. N., Cage, A. G., Wonders, A. A. H., Marret, F. & Pinnington, C. A., 15 Dec 2018, In : Palaeogeography, Palaeoclimatology, Palaeoecology. 511, p. 119-143

    Research output: Contribution to journalArticle

ID: 156506141