Lecture 3 Flashcards
People who engage in systematics are called _______. What are they often also?
Systematists. They are often, but not always, taxonomists as well.
What is the focus of modern systematists?
The “why” in grouping of particular taxa - the theory behind it.
How jas the focus changed in systematics in the past 50 years?
Focus has switched from simply adding new taxa to methods for determining relatedness among taxa. Also, the desire for evolutionarily informative
classifications lead to changes in older taxonomies.
What brand of systematics has particularly accelerated the rate of taxonomic change?
Molecular systematics, as it revealed characteristics of organisms that were not observable before.
Define stratigraphy. What is it used for?
Temporal order in which fossils occur - it is a tool used to help systematists with their classifications.
How did systematists use “common sense” to classify species?
They used it to determine which aspects of morphology seemed more ‘primitive’ vs
‘advanced’
What was fundamentally wrong with old-style systematics? How did this change in the 1960s?
The old-style method of systematics was subjective and strongly influenced by individual preference, so in the 1960s they switches to a more objective style of classification.
Who came up with Hennigian systematics, and why?
Willi Hennig wanted classifications that reflected ancestor-descendant relationships of species and higher taxa (or more generally, shared evolutionary history). He also wanted the methods to be as objective and transparent as possible.
What was the focus of Hennigian systematics?
The intent of the system was to focus on
shared, derived characteristics, which was later called cladistics or phylogenetic systematics
