Exam 20: Phylogeny

One morphological feature of modern cetaceans is a vestigial pelvic girdle.If it is determined that cetacean lineage diverged from the artiodactyls' lineage after the divergence of pigs and other artiodactyla,then what should be true of the vestigial pelvic girdle of cetaceans?

Analisa and Mateo,two research anthropologists interested in deciphering the relatedness between four extinct primates,were studying the similarities and differences among a number of measurements of the complex structures of the jaw fragments they collected,as well as making many other morphological contrasts between other fossilized bones from dozens of collected specimens.In the lab,they noticed the lengths of the bones of the leg,particularly the femur,tibia,and fibula,were very different in all the specimens,whereas the jaw structures were nearly identical among the specimens.What should they tentatively conclude based on this evidence?

Figure 20.1 -Using the phylogenetic tree shown in Figure 20.1,which extinct species should be the best candidate to serve as the outgroup for the clade whose common ancestor occurs at position 2?

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

Figure 20.1 -Assuming the phylogenetic tree shown in Figure 20.1 is an accurate depiction of relatedness,then which of the following should be correct? 1)The entire tree is based on maximum parsimony. 2)If all species depicted here make up a taxon,this taxon is monophyletic. 3)The last common ancestor of species B and C occurred more recently than the last common ancestor of species D and E. 4)Species C is the direct ancestor of both species B and species D. 5)The species present at position 3 is ancestral to C,D,and E.

Placing whales and hippos in the same clade means that

Which of the following is true of all horizontally oriented phylogenetic trees,in which time advances to the right?

Cladograms (a type of phylogenetic tree)constructed from evidence from molecular systematics are based on similarities in

If it turns out that the whale lineage diverged from the lineage leading to hippos after the divergence of the lineage leading to the pigs and other artiodactyls,and if the whales continue to be classified in the order Cetacea,then what becomes true of the taxon Cetartiodactyla?

According to the principle of maximum parsimony,

What evidence allowed biologists to conclude that classification of the tree of life required a three-domain system?

Figure 20.20 Extrapolating backward in time using the molecular clock indicates that the HIV-1 M strain originated around

A polytomy on a phylogenetic tree represents

There is some evidence that extinct reptiles called cynodonts,which arose about 260 million years ago,may have had whisker-like hairs around their mouths.If this is true,then what can be properly said of hair?

Linnaeus was a "fixist" who believed that species remained fixed in the form in which they had been created.Linnaeus would have been uncomfortable with

Which of these would,if it (they)had acted upon a gene,prevent this gene from acting as a reliable molecular clock?

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

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

What is true about this phylogenetic tree?

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