Exam 26: Phylogeny and the Tree of Life

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?

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

Neutral theory proposes that

Use the following figure to answer the questions below. Humans,chimpanzees,gorillas,and orangutans are members of a clade called the great apes,which shared a common ancestor about 18 million years ago.Gibbons and siamangs comprise a clade called the lesser apes.Tree-branch lengths indicate elapsed time. -Together,the lesser apes and great apes shared a common ancestor most recently with other members of their

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. -What can be properly inferred from the above figure?

-Refer to the figure above.Which of the following forms a monophyletic group?

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. -Traditional zoologists have long agreed that birds evolved from dinosaurs.What keeps such zoologists from agreeing that birds,like dinosaurs,should be considered reptiles?

The domestic dog,red fox,and wolf belong to the family Canidae.The dog is Canis lupus familiaris,the red fox is Vulpes vulpes,and the wolf is Canis lupus.Which of the following statements is correct?

Why is the Kingdom Monera no longer part of the modern classification system?

Species that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their

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 -Which of the following is the best explanation for the high degree of sequence homology observed in Exon I among these five species?

-In the phylogenetic trees above,numbers represent species and the same species are shown in both trees.Which two species are represented as sister species in Tree 2 but are not shown as sister species in Tree 1?

Use the following figure to answer the questions below. Humans,chimpanzees,gorillas,and orangutans are members of a clade called the great apes,which shared a common ancestor about 18 million years ago.Gibbons and siamangs comprise a clade called the lesser apes.Tree-branch lengths indicate elapsed time. -The great apes comprise the family Hominidae,whereas the lesser apes comprise the family Hylobatidae.If the extant organisms on the far right side of the above figure comprise the next-most exclusive (i.e.,specific)taxon,then they comprise different

Assuming chimps and gorillas are humans' closest relatives,removing humans from the great ape clade and placing them in a different clade has the effect of making the phylogenetic tree of the great apes

Concerning growth in genome size over evolutionary time,which of these is least associated with the others?

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?

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?

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

From the above figure,which other event occurred closest in time to the divergence of gorillas from the lineage that led to humans and chimps?

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