Exam 23: Broad Patterns of Evolution

The following questions refer to the description and Figure 23.1. Figure 23.1 represents a cross section of the sea floor through a mid-ocean rift valley, with alternating patches of black and white indicating sea floor with reversed magnetic polarities. At the arrow labeled "I" (the rift valley), the igneous rock of the sea floor 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 sea-floor spreading, away from the rift valley. Figure 23.1 -Assuming that the rate of sea-floor spreading was constant during the 1-million-year period depicted in Figure 23.1, what should be the approximate age of marine fossils found in undisturbed sedimentary rock immediately overlying the igneous rock at the arrow labeled "II"?

The following questions refer to the description and Figure 23.1. Figure 23.1 represents a cross section of the sea floor through a mid-ocean rift valley, with alternating patches of black and white indicating sea floor with reversed magnetic polarities. At the arrow labeled "I" (the rift valley), the igneous rock of the sea floor 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 sea-floor 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?

The following questions refer to the description and Figure 23.1. Figure 23.1 represents a cross section of the sea floor through a mid-ocean rift valley, with alternating patches of black and white indicating sea floor with reversed magnetic polarities. At the arrow labeled "I" (the rift valley), the igneous rock of the sea floor 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 sea-floor spreading, away from the rift valley. Figure 23.1 -Which section of sea-floor crust should have the thickest layer of overlying sediment, assuming a continuous rate of sediment deposition?

Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate. Adult female bagworm moths are larval in appearance; they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag. This is a good example of

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

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb. This type of change is illustrative of

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from the air-breathing organ (a simple lung) of an ancestral fish is an example of

The following questions 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. -In each fly species, the entire body segment that gave rise to the original flight wings is missing. The mutation(s) that led to the flightless condition could have

Which factor most likely caused animals and plants in India to differ greatly from species in nearby Southeast Asia?

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

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

One explanation for the evolution of insect wings suggests that wings began as lateral extensions of the body that were used as heat dissipaters for thermoregulation. When they had become sufficiently large, these extensions became useful for gliding through the air, and selection later refined them as flight-producing wings. If this hypothesis is correct, modern insect wings could best be described as

If two continents converge and are united, then the collision should cause

Fossil evidence indicates that several kinds of flightless dinosaurs possessed feathers. If some of these feather-bearing dinosaurs incubated clutches of eggs in carefully constructed nests, this might be evidence supporting the claim that

Adaptive radiations can be a direct consequence of four of the following five factors. Select the exception.

Upon being formed, oceanic islands, such as the Hawaiian Islands, should feature what characteristic, leading to which phenomenon?

Which measurement(s) would help determine absolute dates by radiometric means?

The first terrestrial organisms probably were considered which of the following? 1. burrowers 2) photosynthetic 3) multicellular 4) prokaryotes 5) eukaryotes 6) plants and their associated fungi

Figure 23.2 The following questions refer to the paragraph below. A sediment core is removed from the floor of an inland sea. The sea has been in existence, off and on, throughout the entire time that terrestrial life has existed. Researchers wish to locate and study the terrestrial organisms fossilized in this core. The core is illustrated as a vertical column, with the top of the column representing the most recent strata and the bottom representing the time when land was first colonized by life. -Assuming the existence of fossilized markers for each of the following chemicals, what is the sequence in which they should be found in this sediment core, working from ancient sediments to recent sediments? 1. chitin coupled with protein 2) chlorophyll 3) bone 4) cellulose

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