Organismal variation

I am keenly interested in the history and philosophy of biology and believe that fundamental to understanding evolutionary theory is acknowledging its context historically and philosophically. An appreciation of the origins of our theoretical frameworks for exploring evolution helps us understand in which ways these historical perspectives still inform our research today.

A main focus of my work has been how best to analyse and interpret patterns of morphological variation through time, an area of research that exemplifies the above. The manner in which we conceptualize organismal variation frames our theoretical and methodological outlook and determines not only the kinds of data we can produce but even the kinds of questions that we can ask.

Part of the Linnean heritage of evolutionary biology is an understanding of variation as discrete. Variation was necessarily discretized historically as part of the taxonomic mapping of diversity. Yet this mode of thinking remains dominant to this day, in part due to being formalized, particularly in the field of palaeontology, in the cladistic analyses of the late 20th century. Cladistic analyses require character and character states as data, which introduces serious limitations to the scope of investigation available to evolutionary biologists.

The translation of organismal variation into a set of discrete characters for such analyses strongly reduces the resolution of data available for analyis and consequently limits the research questions we can approach. The effects of this are particularly notable in the field of palaeontology where available data is already very limited and essentially restricted to morphology.

For example, studies of organisms with few or no qualitatively different characters cannot be approached in a cladistic framework. This means that studies of intraspecific variation, for example, is extremely problematic. It is, I believe, in no small part due to the cladistic tradition of palaeontology that the field of paleobiology is still yet to deliver its full potential.

Morphometrics represent an alternative perspective with which to approach morphological variation. Morphometric methods of analyzing biological shape treat variation as continuous, which facilitates studies of higher resolution capable of detecting more subtle patterns of variation.

By developing and using morphometric modes of investigation it is possible to generate new kinds of palaeontological data and thus explore new research questions. For example, variation both within and between species or even separate conspecific assemblages can be detected and analysed. In particular, a combination of data from the fossil record and from neontological specimens provides excellent opportunity to explore emerging evolutionary topics and research fields.

These include investigation of speciation processes in high fidelity, evidence of genetic canalization and plasticity-led evolution as well as, in a neontological context, putative developmental bias in Anolis lizards.

Ultimately the purpose of studying evolutionary patterns of morphological variation is to test theories and hypotheses regarding the processes and consequent patterns or structure of evolution. In my work I prioritize investigations that can inform us about intriguing evolutionary concepts such as those mentioned above.