Systematics as science

The Science of Phylogenetic Systematics: Explanation, Prediction, and Test

When the concept of homology is operationalized with synapomorphy and tested with character congruence, homology and homoplasy are treated as a complement relation, a and not-a, respectively. This leaves homoplasy to be defined nominally, something like operational “error” in the inference of homology. In choosing the most severely tested and least disconfirmed cladogram, those errors are minim...

Demography as social science and policy science

As Science Evolves, How Can Science Policy?

Getting science policy right is a core objective of government that bears on scientific advance, economic growth, health, and longevity. Yet the process of science is changing. As science advances and knowledge accumulates, ensuing generations of innovators spend longer in training and become more narrowly expert, shifting key innovations (i) later in the life cycle and (ii) from solo researche...

The use of hierarchies as organizational models in systematics

A hierarchy is an abstract organizational model of inter-level relationships among entities. When isomorphic with nature, hierarchies are useful for organizing and manipulating our knowledge. Hierarchies have been used in biological systematics to represent several distinct, but interrelated, facets of the evolution of life with different organizational properties, and these distinctions have b...

Phylogenetic Systematics

Since the advent of the theory of evolutio n, o ne of the tasks of biology has bee n to i nvestigate the phyloge netic relatio nship betwee n species. This task is especially impor ta nt because all of the differe nces which exist betwee n species, whether i n morphology, physiology , or ecology, i n ways of behavior, or even i n geographical distributio n, have evolved , like the species thems...