Exam 23: Broad Patterns of Evolution

Figure 23.3 -Hawaii is the most southeastern of the seven islands and is also closest to the seafloor spreading center from which the Pacific plate originates, which lies about 5,600 km farther to the southeast. Assuming equal sedimentation rates, what should be the location of the thickest sediment layer and, thus, the area with the greatest diversity of fossils above the oceanic crust?

Which of these planet substances is the richest source of fossils?

Please use the following information to answer the question(s) below. Figure 23.1 represents a cross section of the seafloor through a mid-ocean rift valley, with alternating patches of black and white indicating seafloor with reversed magnetic polarities. At the arrow labeled I (the rift valley), the igneous rock of the seafloor is so young that it can be accurately dated using carbon-14 dating. At the arrow labeled III, however, the igneous rock is about 1 million years old, and potassium-40 dating is typically used to date such rocks. Note: The horizontal arrows indicate the direction of seafloor spreading, away from the rift valley. Figure 23.1 -If a particular marine organism is fossilized in the sediments immediately overlying the igneous rock at the arrow labeled II, at which other location(s), labeled A-E, would a search be most likely to find more fossils of this organism?

Please use the following information to answer the question(s) below. All animals with eyes or eyespots that have been studied so far share a gene in common. When mutated, the gene Pax-6 causes lack of eyes in fruit flies, tiny eyes in mice, and missing irises (and other eye parts) in humans. The sequence of Pax-6 in humans and mice is identical. There are so few sequence differences with fruit fly Pax-6 that the human/mouse version can cause eye formation in eyeless fruit flies, even though vertebrates and invertebrates last shared a common ancestor more than 500 million years ago. -An improved method of radiometric dating, which filtered out contaminants, showed that most Neanderthal bones in Europe are older than suggested by earlier dating. This new dating suggests that Neanderthals' time on the planet did not overlap with modern humans. Radiocarbon dating depends on measuring the radioactive isotopes of carbon-14. Which of the following statements supports the null hypothesis that modern humans and Neanderthals did not occupy the same sites at the same time?

The loss of ventral spines by modern freshwater sticklebacks is due to natural selection operating on the phenotypic effects of Pitx1 gene

Larval flies (maggots) express the Ubx gene in all of their segments and thereby lack appendages. If this same gene continued to be expressed throughout subsequent developmental stages, except in the head region, and if the result was a fit, sexually mature organism that still strongly resembled a maggot, this would be an example of

Which effect of continental drift would allow scientists to track the history of life on the planet?

In the 5 to 7 million years that the hominid lineage has been diverging from its common ancestor with the great apes, dozens of hominid species have arisen, often with several species coexisting in time and space. As recently as 30,000 years ago, Homo sapiens coexisted with Homo neanderthalensis. Both species had large brains and advanced intellects. The fact that these traits were common to both species is most easily explained by which of the following?

Radiometric dating is based on the

Hox genes are a group of related genes

Figure 23.3 -According to the theory of seafloor spreading, oceanic islands, such as the Hawaiian Islands depicted in Figure 23.3, form as oceanic crustal plates move over a stationary "hot spot" in the mantle. Currently, the big island of Hawaii is thought to be over a hot spot, which is why it is the only one of the seven islands that has active volcanoes. What should be true of the island of Hawaii? 1) Scientists in search of ongoing speciation events are more likely to find them there than on the other six islands. 2) Its species should be more closely related to those of nearer islands than to those of farther islands. 3) It should have a rich fossil record of terrestrial organisms. 4) There is a good chance of finding endemic species on this island. 5) On average, it should have fewer species per unit surface area than the other six islands.

An organism has a relatively large number of Hox genes in its genome. Which of the following is true of this organism?

A change in the nucleotide sequence of a gene effects function of that gene

Figure 23.3 - Figure 23.5 Which period had the greatest rate of extinction?

Many species of snakes lay eggs. However, in the forests of northern Minnesota where growing seasons are short, only live-bearing snake species are present. This trend toward species that perform live birth in a particular environment is an example of

If the half-life of carbon-14 is about 5,730 years, then a fossil that has 1/16th the normal proportion of carbon-14 to carbon-12 should be about how many years old?

The major evolutionary episode corresponding most closely in time with the formation of Pangaea was the

Please use the following information to answer the question(s) below. All animals with eyes or eyespots that have been studied so far share a gene in common. When mutated, the gene Pax-6 causes lack of eyes in fruit flies, tiny eyes in mice, and missing irises (and other eye parts) in humans. The sequence of Pax-6 in humans and mice is identical. There are so few sequence differences with fruit fly Pax-6 that the human/mouse version can cause eye formation in eyeless fruit flies, even though vertebrates and invertebrates last shared a common ancestor more than 500 million years ago. -Pax-6 usually causes the production of a type of light-receptor pigment. In vertebrate eyes, though, a different gene (the rh gene family) is responsible for the light-receptor pigments of the retina. The rh gene, like Pax-6, is ancient. In the marine ragworm, for example, the rh gene causes production of c-opsin, which helps regulate the worm's biological clock. Which of these most likely accounts for vertebrate vision?

The following question(s) refer to this hypothetical situation. A female fly, full of fertilized eggs, is swept by high winds to an island far out to sea. She is the first fly to arrive on this island and the only fly to arrive in this way. Thousands of years later, her numerous offspring occupy the island, but none of them resembles her. There are, instead, several species, each of which eats only a certain type of food. None of the species can fly, for their flight wings are absent, and their balancing organs (in other words, halteres) are now used in courtship displays. The male members of each species bear modified halteres that are unique in appearance to their species. Females bear vestigial halteres. The ranges of all of the daughter species overlap. -If these fly species lost the ability to fly independently of each other as a result of separate mutation events in each lineage, then the flightless condition in these species could be an example of

Please use the following information to answer the question(s) below. All animals with eyes or eyespots that have been studied so far share a gene in common. When mutated, the gene Pax-6 causes lack of eyes in fruit flies, tiny eyes in mice, and missing irises (and other eye parts) in humans. The sequence of Pax-6 in humans and mice is identical. There are so few sequence differences with fruit fly Pax-6 that the human/mouse version can cause eye formation in eyeless fruit flies, even though vertebrates and invertebrates last shared a common ancestor more than 500 million years ago. -The appearance of Pax-6 in all animals with eyes can be explained in multiple ways. Based on the information given, which explanation is most likely?