Exam 26: Phylogeny and the Tree of Life

Use the following information and figure to answer the questions below. Traditionally, whales and hippopotamuses have been classified in different orders, the Cetacea and the Artiodactyla, respectively. Recent molecular evidence, however, indicates that the whales' closest living relatives are the hippos. This has caused some zoologists to lump the two orders together into a single clade, the Cetartiodactyla. There is no consensus on whether the Cetartiodactyla should be accorded order status or superorder status. This is because it remains unclear whether the whale lineage diverged from the lineage leading to the hippos before or after the other members of the order Artiodactyla (pigs, camels, etc.) diverged (see the figure below). This figure contrasts the "Within the artiodactyls" origin of the whale lineage with the "Without the artiodactyls" origin of the whale lineage. -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 order Artiodactyla?

The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that

The following questions refer to the description below. You are taking an art class and your instructor asks you to draw several animals, including a shark, a dolphin, and a penguin. As you draw these animals you notice that they all have a fusiform shape; in other words, they are tapered at both ends. Despite their similar shape, you are well aware that the shark is a fish, the dolphin is a mammal, and the penguin is a bird. -You are also asked to draw animals that fly, including insects, birds, and bats. You read that fossil evidence suggests that bat wings and bird wings arose independently from forelimbs of different tetrapod ancestors. If this is the case, then a bird's wing is ________ to a bat's wing.

Which of the following items does not necessarily exist in a simple linear relationship with the number of gene-duplication events when placed as the label on the vertical axis of the following graph?

Use this figure to answer the following questions. -Which extinct species should be the best candidate to serve as the outgroup for the clade whose common ancestor occurs at position 2 in the above figure?

A phylogenetic tree constructed using sequence differences in mitochondrial DNA would be most valid for discerning the evolutionary relatedness of

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

What kind of evidence has recently made it necessary to assign the prokaryotes to either of two different domains, rather than assigning all prokaryotes to the same kingdom?

The next questions refer to the following table, which compares the percent sequence homology of four different parts (two introns and two exons) of a gene that is found in five different eukaryotic species. Each part is numbered to indicate its distance from the promoter (e.g., Intron I is the one closest to the promoter). The data reported for species A were obtained by comparing DNA from one member of species A to another member of species A. % Sequence Homology -Regarding these sequence homology data, the principle of maximum parsimony would be applicable in

Use the following information to answer the questions below. 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. Bird anatomy has become highly modified as birds have adapted to flight, without their genes having undergone nearly as much change. -Taxonomically, what should be done with the birds?

Nucleic acid sequences that undergo few changes over the course of evolutionary time are said to be conserved. Conserved sequences of nucleic acids

The following questions refer to this phylogenetic tree, depicting the origins of life and of the three domains. Horizontal lines indicate instances of gene or genome transfer. A possible phylogenetic tree for the three domains of life. -If the early history of life on Earth is accurately depicted by the above figure, then which statement is least in agreement with the hypothesis proposed by this tree?

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

To apply parsimony to constructing a phylogenetic tree

Which of these four gene parts should allow the construction of the most accurate phylogenetic tree, assuming that this is the only part of the gene that has acted as a reliable molecular clock?

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

The next questions refer to the following table, which compares the percent sequence homology of four different parts (two introns and two exons) of a gene that is found in five different eukaryotic species. Each part is numbered to indicate its distance from the promoter (e.g., Intron I is the one closest to the promoter). The data reported for species A were obtained by comparing DNA from one member of species A to another member of species A. % Sequence Homology -Based on the tabular data, and assuming that time advances vertically, which cladogram (a type of phylogenetic tree)is the most likely depiction of the evolutionary relationships among these five species?

Consider the human arm, a dog's foreleg, and a seal's flipper. These three structures are examples of ________ structures.

The legless condition that is observed in several groups of extant reptiles is the result of

Which of these can be properly inferred from the phylogeny in the above figure?