Major divisions in the geologic record are marked by
a. Radioactive dating.
b. Distinct changes in the types of fossilized life.
c. Regular time intervals measured in millions of years.
d. The appearance, in order, of prokaryotes, eukaryotes, protists, animals, plants, and fungi.

Why was finding a close relationship between mitochondrial DNA and bacterial DNA considered particularly strong evidence in favor of the endosymbiosis theory?

In the late 1700s, machines that could blast through rock to build roads and railways were invented, exposing deep layers of rocks. How would you expect this development to aid the science of paleontology?

Coral reefs are biodiverse ecosystems that provide food, income, coastal protection, and many other services to millions of people. Yet coral reefs are under threat from human impacts such as climate change—many corals cannot tolerate the warming ocean water and have suffered massive 'bleaching' events, which can be fatal. Researchers have discovered that some corals have the capacity to acclimatize to warmer water, while other corals do not. The researchers fear that because corals are long-lived colonial animals and thus evolve slowly, they may not be able to adapt to global warming fast enough to avoid extinction. Explain how the difference between acclimatize and adapt is important to the fate of corals.

In an experiment, you create two groups of liposomes in a solution containing 0.1 M NaCl—one made from red blood cell membranes and the other from frog egg cell membranes. When the liposomes are placed in water, those with red blood cell membranes burst more rapidly than those made from egg membranes. What could explain these results? Select True or False for each of the following statements.

a. T/F The red blood cell liposomes are more hypertonic relative to water than the frog egg liposomes.

b. T/F The red blood cell liposomes are more hypotonic relative to water than the frog egg liposomes.

c. T/F The red blood cell liposomes contain more aquaporins than the frog egg liposomes.

d. T/F The frog egg liposomes contain ion channels, which are not present in the red blood cell liposomes.

Write a paragraph briefly describing the kinds of scientific evidence for evolution.

In the early 1800s, French naturalist Jean Baptiste Lamarck suggested that the best explanation for the relationship of fossils to current organisms is that life evolves. He proposed that by using or not using its body parts, an individual may change its traits and then pass those changes on to its offspring. He suggested, for instance, that the ancestors of the giraffe had lengthened their necks by stretching higher and higher into the trees to reach leaves. Evaluate Lamarck's hypotheses from the perspective of present-day scientific knowledge.

The vast majority of animals that ever existed are now extinct, but Tereza Jezkova and John Wiens wondered which variables were most important in driving the diversification of species that exist today.

Why are there so many species in some phyla, such as Cnidaria (see photo), but so few in others, such as Ctenophora?

Draw a horizontal axis to represent the number of species within phyla using a logarithmic scale (1, 10, 100, 1000 species, etc.). Then use Table 30.1 to map seven representative phyla from small to large at intervals of about an order of magnitude on this scale.

The vast majority of animals that ever existed are now extinct, but Tereza Jezkova and John Wiens wondered which variables were most important in driving the diversification of species that exist today. Why are there so many species in some phyla, such as Cnidaria, but so few in others, such as Ctenophora? Based on your reading of this chapter, propose at least five traits that you think might have been most important in triggering diversification within phyla (examples: origin of hearing, origin of internal fertilization).