Chapter 8 Review

During Earth's early history, microbial life on land contributed to the formation of soil, which in turn led to the evolution of land plants. Which term describes this chain of events?

• coevolution

• convergent evolution

• adaptive radiation

• punctuated equilibrium

A team of scientists is excavating fossils from a rock layer. They discover fossils of trilobites, which are useful as index fossils. Which information about the rock layer is provided by the trilobite fossils?

• the absolute age of the fossils contained in the rocks

• the absolute age of the rocks

• the number of fossils that the rocks contain

• the approximate or relative ages of the rocks and the fossils they contain

A scientist is using potassium-40, a radioactive isotope of potassium, to find the absolute age of a fossil by radiometric dating. The scientist determines that about three-fourths of the original potassium-40 atoms in the fossil now remain in the fossil. What additional information is necessary for the scientist to determine the absolute age of the fossil?

• the half-life of potassium-40

• the identity of an index fossil

• the atomic mass of potassium-40

• the total mass of the fossil

Which of the following describes an example of life coevolving with a change in Earth's systems?

• Large grassland birds developed on several different continents.

• Many species of reptiles and amphibians evolved gradually over extremely long periods of time.

• A sudden environmental change triggers a mass extinction of a group of mammal species.

• Oceans flooded large land areas, creating shallow marine habitats in which animal groups split into different species.

Which theory or idea is most useful for determining the positions of the continents as shown in the map?

• the hypothesis of continental drift, which states that continents move across an unchanging ocean

• the idea of deep time, which explains that Earth is much older than human history

• the theory of plate tectonics, which explains that Earth's surface is divided into moving plates

• the theory of evolution, which explains how living things and their environment can affect one another

Which of the following best describes a mass extinction, but not background extinction?

• Species go extinct because their environment no longer supports them.

• Species go extinct because other species are better adapted to the environment.

• Extinctions of many species drastically alter whole ecosystems.

• Extinctions affect only species of large animals, and not small animals, plants, or microorganisms.

According to the theory of punctuated equilibrium, which group of species does it apply to?

• all species that developed new adaptations over time

• species that evolved very rapidly during relatively brief time spans

• species that evolved gradually and at a relatively constant rate

• species that changed very little over geologic time

When is adaptive radiation most likely to occur, and for what reason?

• after a mass extinction, because the survivors give rise to species that fill new niches

• just before a mass extinction, because species are competing intensely for limited resources

• when the climate is warmest, because high temperatures act to increase the rate of evolutionary change

• when the climate is stable, because a stable environment tends to decrease the rate of evolutionary change

Which of the following would be the strongest counter-argument AGAINST Cory's claim that aardvarks and anteaters evolved from a common ancestor due to their similar tongue usage for eating insects?

• Aardvarks and anteaters are examples of convergent evolution due to similar environmental challenges.

• Aardvarks and anteaters have different genetic markers that clearly distinguish their evolutionary paths.

• The similarities in tongue structure are due to similar diets, not common ancestry.

• Aardvarks and anteaters both evolved in the same geographic region, supporting a common ancestor.

Which observation would BEST support Vera's claim that the evolution of the heliconia flower shape is an example of coevolution?

• A bird species has a beak shape that fits perfectly with the heliconia flower, facilitating pollination.

• The heliconia flower is the only flower in its habitat with a curved shape.

• Heliconia flowers have a similar color to other flowers in the same geographic area.

• Insects that pollinate flowers cannot reach the nectar of heliconia due to its shape.