In a comparison of birds and mammals, the condition of having four limbs is

a shared ancestral character.

To apply parsimony to constructing a phylogenetic tree,

choose the tree that represents the fewest evolutionary changes, in either DNA sequences or morphology.

In Figure 26.4, which similarly inclusive taxon descended from the same common ancestor as Canidae?

Mustelidae

Three living species X, Y, and Z share a common ancestor T, as do extinct species U and V. A grouping that consists of species T, X, Y, and Z (but not U or V) makes up

a paraphyletic group.

Based on the tree below, which statement is not correct?

Lizards are more closely related to salamanders than to
humans.

If you were using cladistics to build a phylogenetic tree of cats, which of the following would be the best outgroup?

wolf

The relative lengths of the frog and mouse branches in the phylogenetic tree in Figure 26.13 indicate that

the homolog has evolved more slowly in mice.

The best classification system is that which most closely ___.

reflects evolutionary history

The various taxonomic levels (namely, genera, classes, etc.) of the hierarchical classification system differ from each other on the basis of ___.

their inclusiveness

Which of the following is (are) problematic when the goal is to construct phylogenies that accurately reflect evolutionary history?

Two of the responses are correct.

In a comparison of birds and mammals, having four limbs is ___.

a shared ancestral character

If organisms A, B, and C belong to the same class but to different orders and if organisms D, E, and F belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?

D and F

Which eukaryotic kingdom is polyphyletic, and therefore unacceptable, based on cladistics?

Protista

Traditionally, zoologists have placed birds in their own class, Aves. More recently, molecular evidence has shown that birds are more closely related to reptiles than their anatomy reveals. Genetically, birds are more closely related to crocodiles than crocodiles are to turtles. Thus, bird anatomy has become highly modified as they have adapted to flight, without their genes having undergone nearly as much change. Taxonomically, what should be done with the birds?

Science is consensual. Taxonomy is a science. Variant classification schemes involving the birds should be tolerated until consensus is reached.

The term homoplasy is most applicable to which of the following features?

the legless condition found in various lineages of extant lizards

Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of sequence homology?

Dogs and wolves shared a common ancestor very recently.

What important criterion was used in the late 1960s to distinguish between the three multicellular eukaryotic kingdoms of the five-kingdom classification system?

the nutritional modes they employ

The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as ___.

homoplasies

Which of the following pairs are the best examples of homologous structures?

bones in the bat wing and bones in the human forelimb

To apply parsimony to constructing a phylogenetic tree, ___.

choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to ___.

possession of analogous structures

When using a cladistic approach to systematics, which of the following is considered most important for classification?

shared derived characters

A large proportion of archaeans are extremophiles, so called because they inhabit extreme environments with high acidity, salinity, and/or temperature. Such environments are thought to have been much more common on the primitive Earth. Thus, modern extremophiles survive only in places that their ancestors became adapted to long ago. Which of the following is, consequently, a valid statement about modern extremophiles, assuming that their habitats have remained relatively unchanged?

On a phylogenetic tree whose branch lengths are proportional to the amount of genetic change, the branches of the extremophiles should be shorter than the non-extremophilic archaeans.

Neutral theory proposes that ___.

a significant proportion of mutations are not acted upon by natural selection.

Members of which kingdom have cell walls and are all heterotrophic?

Fungi

25) The lakes of northern Minnesota are home to many similar species of damselflies of the genus Enallagma that have apparently undergone speciation from ancestral stock since the last glacial retreat about 10,000 years ago. Sequencing which of the following would probably be most useful in sorting out evolutionary relationships among these closely related species?

mitochondrial DNA

The most important feature that permits a gene to act as a molecular clock is ___.

having a reliable average rate of mutation.