A paleontologist estimates that when a particular rock formed, it contained 12 mg of the

Distinguish between microevolution, speciation, and macroevolution.

Bird guides once listed the myrtle warbler and Audubons warbler as distinct species that lived side by side in parts of their ranges. However, recent books describe them as the eastern and western forms of a single species, the yellow-rumped warbler. Apparently, the two kinds of warblers a. live in the same areas. b. successfully interbreed. c. are almost identical in appearance. d. are merging to form a single species

Identify each of the following reproductive barriers as prezygotic or postzygotic. a. One lilac species lives on acidic soil, another on basic soil. b. Mallard and pintail ducks mate at different times of the year. c. Two species of leopard frogs have different mating calls. d. Hybrid offspring of two species of jimsonweed always die before reproducing. e. Pollen of one kind of pine tree cannot fertilize another kind.

Why is a small, isolated population more likely to undergo speciation than a large one?

Many species of plants and animals adapted to desert conditions probably did not arise there. Their success in living in deserts could be due to ______________, structures that originally had one use but became adapted for different functions.

Mass extinctions a. cut the number of species to the few survivors left today. b. resulted mainly from the separation of the continents. c. occurred regularly, about every million years. d. were followed by diversification of the survivors.

The animals and plants of India are almost completely different from the species in nearby Southeast Asia. Why might this be true? a. They have become separated by convergent evolution. b. The climates of the two regions are completely different. c. India is in the process of separating from the rest of Asia. d. India was a separate continent until relatively recently

A paleontologist estimates that when a particular rock formed, it contained 12 mg of the radioactive isotope potassium-40. The rock now contains 3 mg of potassium-40. The half-life of potassium-40 is 1.3 billion years. From this information, you can conclude that the rock is approximately ______________ billion years old.

Why are biologists careful to distinguish similarities due to homology from similarities due to analogy when constructing phylogenetic trees?

In the three-domain system, which two domains contain prokaryotic organisms?

Imagine you are conducting fieldwork and discover two groups of mice living on opposite sides of a river. Assuming that you will not disturb the mice, design a study to determine whether these two groups belong to the same species. If you could capture some of the mice and bring them to the lab, how might that affect your experimental design?

Interpreting Data The carbon-14/carbon-12 ratio of a fossilized skull is about 6.25% that of the skull of a present-day animal. Using the graph below, what is the approximate age of the fossil?

Most biologists are alarmed at the current rate of species extinction. What are some reasons for their concern? Considering that life has endured numerous mass extinctions and has always bounced back, how would this sixth mass extinction be different? What might be some consequences for the surviving species?

The red wolf (Canis rufus) was once widespread in the southeastern United States but was declared to be extinct in the wild. Biologists bred captive red wolf individuals and reintroduced them into areas of eastern North Carolina, where they are federally protected as endangered species. The current wild population is estimated to be about 100 individuals. However, a new threat to red wolves has arisen: hybridization with coyotes (Canis latrans), which have become more numerous in the areas inhabited by red wolves. Although red wolves and coyotes differ in morphology and DNA, they are capable of interbreeding and producing fertile offspring. Social behavior is the main reproductive barrier between the species and is more easily overcome when same-species mates are rare. For this reason, some people think that the endangered status of the red wolf should be withdrawn and resources should not be spent to protect what is not a pure species. Do you agree? Why or why not?