Exam 24: Systematic Biology: Phylogeny and Classification

The best outgroup to use for resolving phylogenetic relationships of vascular plants is the ____ because all of its character states are considered ancestral.

To identify the optimal phylogenetic tree from multiple potential trees, many systematists use the ____ , which states that the simplest plausible explanation of any phenomenon is the best. ​

Common names for a species may vary widely among different groups of people who use those names, and thus are not reliable for scientific use.

Similarity in any type of biological trait resulting from shared ancestry is called ____. ​

The scientific name of a polar bear is Ursus maritimus . The first part, Ursus , is the ____ name. ​

Fossils of plants found in deeper geologic layers do not show vascular tissues, while fossils in shallower geologic layers include some specimens with and some without vascular tissues. Thus, vascular tissue in plants is considered a ____ character. ​

In the absence of evidence from fossils, systematists frequently use a technique called ____ to identify ancestral and derived character states.

An ancestral ____ gave rise to animals including mammals, lizards, turtles, and birds.

The organisms included within any category of the taxonomic hierarchy comprise a(n)____.

On a phylogenetic tree, two clades that emerge from the same node are called ____ because they are each other's closest relatives. ​

When systematists compare vertebrates to all other animals, the absence of a vertebral column is the ____ character state and the presence of a vertebral column is the ____.

Linear chromosome structure is a character unique to members of the domain(s)____. ​

Because ____ character states are shared by the ingroup and the outgroup, phylogenetic trees are constructed by cladistic analyses that group species that share only ____ character states.

Crocodilians are classified as reptiles; however, they share a common ancestor with birds, which are not reptiles. Therefore, Reptilia is a ____ taxon. ​

In the system of binomial nomenclature, species are assigned a two-part name: the first part is the ____ and the second part is the ____name. ​

According to cladistics, a derived character state is called a(n)____. ​

Which traits were originally used for classifying organisms into taxonomic categories? ​