Chapter 28

All of the following events can trigger an adaptive radiation EXCEPT _____. A) an unusual event splitting a habitat, such as a severe hurricane B) the evolution of a new morphological feature C) the extinction of competitors

A

For many years scientists believed that almost all animal lineages burst into being during the Cambrian era (just after the end of the Precambrian super eon). However, there have been many recent findings of animal-like fossils and "trace fossils" (fossils of an animal-like organisms movement) from the late Precambrian. Which of the following best explains why it took so long to realize there was animal-like life in the Precambrian? A) Animals from the late Precambrian had soft bodies. B) There were many hard-shelled animals in the Cambrian. C) The global climate was such that there was poor fossilization in the Precambrian. D) There were very few animals during this period.

A

How were conditions on the early Earth of more than three billion years ago different from those on today's Earth? Unlike Earth today, early Earth _____. A) had an atmosphere rich in gases released from volcanic eruptions, colliding with meteors B) had an oxidizing atmosphere C) experienced little high energy radiation from the sun D) had an atmosphere with significant quantities of ozone

A

An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to _____. A) change the atmosphere from oxidizing to reducing B) make it easier to maintain reduced molecules C) cause iron in ocean water and terrestrial rocks to rust (oxidize) D) prevent the formation of an ozone layer

C

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 _____. A) duplicated all of the Hox genes in these flies' genomes B) resulted in paedomorphosis C) altered the expression of a Hox gene D) originated in another species

C

The Permian period ended and then rapid speciation occurred as new animal and plant forms evolved. The most likely explanation for this is _____. I) adaptive radiation II) ecological opportunity III) lack of competition IV) morphological innovation A) just one of the above B) two of the above C) three of the above D) all of the above

C

Upon being formed, oceanic islands, such as the Hawaiian Islands, should feature what characteristic, leading to which phenomenon? A) mass extinctions, leading to bottleneck effect B) major evolutionary innovations, leading to rafting to nearby continents C) a variety of empty ecological niches, leading to adaptive radiation D) adaptive radiation, leading to founder effect

C

What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? 1. origin of mitochondria 2. origin of multicellular eukaryotes 3. origin of chloroplasts 4. origin of cyanobacteria 5. origin of fungal-plant symbioses A) 4, 3, 2, 1, 5 B) 4, 1, 2, 3, 5 C) 4, 1, 3, 2, 5 D) 4, 3, 1, 5, 2

C

According to the theory of sea-floor spreading, oceanic islands, such as the Hawaiian Islands depicted in the figure above, 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 large 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 here than on the other six large 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. It should have species that are not found anywhere else on Earth. 5. On average, it should have fewer species per unit surface area than the other six islands. A) 1, 2, and 3 B) 1, 2, and 5 C) 1, 2, 3, and 4 D) 1, 2, 4, and 5

D

Which factor most likely caused animals and plants in India to differ greatly from species in nearby southeast Asia? A) The climates of the two regions are similar. B) India is in the process of separating from the rest of Asia. C) Life in India was wiped out by ancient volcanic eruptions. D) India was a separate continent until forty-five million years ago.

D

Which of the following organisms would be most likely to fossilize? A) a rare worm B) a common worm C) a rare squirrel D) a common squirrel

D