Expunging a Blended Class: The Fall of Kingdom Protozoa

In yesterday's blog, we introduced and defined the term "Class blending". Today's blog extends this discussion by describing the most significant and most enduring class blending error to impact the natural sciences: the artifactual blending of all single cell organisms into the blended class, Protozoa.For well over a century, biologists had a very simple way of organizing the eukaryotes (i.e., the organisms that were not bacteria, whose cells contained a nucleus) (1). Basically, the one-celled organisms were all lumped into one biological class, the protozoans (also called protists). With the exception of animals and plants, and some of the fungi (e.g., mushrooms), life on earth is unicellular. The idea of lumping every type of unicellular organism into one class, having shared properties, shared ancestry, and shared descendants, made no sense. What's more, the leading taxonomists of the nineteenth century, such as Ernst Haeckel (1834 - 1919), understood the class Protozoa was at best, a temporary grab-bag holding unrelated organisms that would eventually be split into their own classes. Well, a century passed, and complacent taxonomists preserved the Protozoan class. In the 1950s, Robert Whittaker elevated Class Protozoa as a kingdom in his broad new "Five Kingdom" classification of living organisms (2). This classification (more accurately, misclassification) persisted through the last five decades of the twentieth century. Modern classifications, based on genetics...
Source: Specified Life - Category: Information Technology Tags: Apicomplexa classification complexity data science irreproducible results ontologies ontology protists protoctista protozoa Source Type: blogs