Exam 23: Broad Patterns of Evolution

Which group of tetrapods had the first examples of specialized teeth?

For purposes of differentiation, what is the unique feature of the jaw fossils of nonmammalian tetrapods?

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

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

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

Adaptive radiation

A researcher discovers a fossil of what appears to be one of the oldest-known multicellular organisms. The researcher could estimate the age of this fossil based on

Exaptations

Which of the following is a biological cause of extinctions?

A difficulty in presenting evidence for a sixth mass extinction is

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

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

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

The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that

The evolution of mammals from early tetrapods

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 - Figure 23.2 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 in Figure 23.2 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

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

What is true of the fossil record of mammalian origins?

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. -Which of these fly organs, as they exist in current fly populations, best fits the description of an exaptation?

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. -Scientists, looking at the range of beak shapes and sizes across different finch species, observed that the thicker beak expressed a gene known as BMP4 early in development. To verify that the BMP4 gene itself could trigger the growth of bigger beaks, researchers increased the production of BMP4 in the developing beaks of chicken embryos. Which of the following results would explain why BMP4-treated chicks began growing wider, taller beaks?