Natural History Photographs


Some notes on my use of taxonomy

The pages on this site dedicated to animals, plants and fungi are organized systematically. In itself this is unremarkable, but the choice is far from innocuous. Modern classifications are in line with our knowledge about evolutionary relationships; but for many taxa, this knowledge still is in a state of flux, with major revisions frequently happening. This applies especially to groups for which morphological evidence is insufficient to arrive at a reliable phylogeny. For such groups, the recent developments in DNA sequencing technology have opened up a completely new window on the evolutionary relationships. As it takes a while before the dust thrown up by the new data will have settled, the classifications of these groups are still quite volatile. Thus, there is often more than one option to organize the material on this site.

In organizing my photos taxonomically, I thus have to make choices, choices that sooner or later may become outdated. For instance, insights into the phylogenetic relationships between digger wasps (Crabronidae) and bees (Apidae) have changed since I created the pages dedicated to them. Then, Crabronidae and Apidae where seen as sister groups; but by the insights of 2017, bees originate within the Crabronidae, making the latter group paraphyletic - a mortal sin in today's taxonomy. To correct that sin in my presentation, I will thus have to bring my presentation in line with current insights.

Even though I aim to present my material according to recent insights about phylogenenetic relationships, I do not always strictly adhere to this intention. There are two reasons to not always rely on the newest phylogeny, one practical and one more principled. The practical reason is that it may take quite some time to rework the organization of the presentation of a praticular group, depending on how large the revision is. I may choose not to prioritize such a revision if other changes are more pressing. The more principled reason is that when a well-established classification is to be overthrown, I prefer to base my presentation on the new concensus view; but such a view is not always available. If a consensus view isn't even remotely in sight, I prefer to stick to the outdated but well-established view, as I did for a long time for the Hymenoptera.

Till quite recently (say 2015), I used a variety of sources, often based on convenience. More recently, I started to document the sources I used. Clearly this is a work in continuous progress; below I document the sources I used in organizing the pages for the various groups. In view of my recent change in approach, this list is far from complete, and I intend to update it regularly.

References
  • Plants
    • General outline: Judd, Campbell, Kellogg, Stevens & Donoghue. 2008. Plant Systemetics: a Phylogenetic Approach, 3rd ed. Sinauer Associates, Inc
    • Flowering plants: APG IV (2016). An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV. Botanical Journal of the Linnean Society 181: 1-20.
    • Status of scientific names: The Pant List, a working list of all known plant species. It provides the names currently in use and indicates their status, including a level of confidence for that status. Since May 2017 I check names of newly added species against this database, and I only use names that are accepted according to this website.
    • Taxonomy of Asteraceae: Global Compositae Checklist
  • Fungi
    • Lichens
      • General outline: Lücking, Hodkinson and Leavitt (2016): The 2016 classification of lichenized fungi in the Ascomycota and Basidiomycota - Approaching one thousand genera. The Bryologist 119(4):361-416
      • Collemataceae: Otálora, Jørgensen & Wedin, 2014: A revised generic classification of the jelly lichens, Collemataceae. Fungal Diversity 64:275-293
      • Teloschistaceae: Arup, Søchting and Frödén (2013). A new taxonomy of the family Teloschistaceae. Nordic Journal of Botany 31: 16-83
    • Status of scientific names: Index Fungorum, provides information on current accepted use of scientific names. It also provides information on the higher order classification. For lichens, if this information is inconsistent with Lücking, Hodkinson and Leavitt (2016), I follow the latter source.
  • Animals