Taxonomist vs Systemicist

Recently, I have had to teach my students the difference between taxonomy and systematics when classifying species. Taxonomists describe the observable features and functions of an organism, and systemicists find hypothetical relationships between them. I found it easiest to explain it with cars...*

Clockwise top left: Dodge Rampage, Ford Ranchero, and Chevrolet El Camino

The vehicles pictured above could be described by a taxonomist as car-pickup truck hybrids dating back to the 1970s. The flatbed space is comparable, the number of doors is the same amongst all three specimens, and I would suspect all three have bench seats and rear-wheel drive. A taxonomist may realize the small differences in these vehicles, but would generally classify these as similar. A systemicist would take things one step further and find out how they are related. In this case, there is no relation! They have all stemmed from different vehicular lineages: Dodge, Ford and Chevrolet. When taxonomists observe enough vehicles over a long time systemicists review their observations to find links in the chain and piece together phylogenetic trees like this one. Many more cars have come and gone since the three above in the face of capitalistic selection pressures, resulting in vehicles like those below. They look very different; as different as elephants and pigs, and opossums and kangaroos! But, they are still related.

Clockwise top left: Dodge Viper, Ford F650, Chevrolet Volt

*Depending on your browser and screen resolution, the pictures may not actually appear in a clockwise pattern.