Chapter 15

You set your time machine for 3 billion years ago and push the start button. When the dust clears, you look out the window. Which of the following describes what you would probably see? a. a cloud of gas and dust in space b. green scum in the water c. land and water sterile and devoid of life d. an endless expanse of red-hot molten rock

Ancient photosynthetic prokaryotes were very important in the history of life because they a. produced the oxygen in the atmosphere. b. are the oldest-known archaea. c. were the first multicellular organisms. d. showed that life could evolve around deep-sea vents.

The animals and plants of India are very different from the species in nearby Southeast Asia. Why might this be true? a. India was once covered by oceans and Asia was not. 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 about 45 million years ago.

Adaptive radiations may be promoted by all of the following except one. Which one? a. mass extinctions that result in vacant ecological niches b. colonization of an isolated region with few competitors c. a gradual change in climate d. a novel adaptation

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. Evidence indicates that early fish gulped air into primitive lungs, helping them survive in stagnant waters. The evolution of the swim bladder from lungs of an ancestral fish is an example of a. an evolutionary trend. b. paedomorphosis. c. the gradual refinement of a structure with the same function. d. exaptation.

If you were using cladistics to build a phylogenetic tree of cats, which would be the best choice for an outgroup? a. kangaroo b. leopard c. domestic cat d. iguana

Which of the following could provide the best data for determining the phylogeny of very closely related species? a. the fossil record b. their morphological differences and similarities c. a comparison of nucleotide sequences in homologous genes and mitochondrial DNA d. a comparison of their ribosomal DNA sequences

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.

Distinguish between microevolution and macroevolution.

How can the Darwinian concept of descent with modification explain the evolution of such complex structures as an eye?

What types of molecular comparisons are used to determine the very early branching of the tree of life? Explain.

Measurements indicate that a fossilized skull you unearthed has a carbon-14: carbon- 12 ratio about \(1 / 16\) th that of the skulls of present-day animals. What is the approximate age of the fossil? (The half-life of carbon-14 is 5,730 years.)