Chapter 13 + 14 Quiz

A paleontologist estimates that when a particular rock formed, it contained 12 mg of the radioactive isotope potassium-40. The rock now contains 3mg of p40. The half-life of p40 is 1.3 billion year. From this information, you can conclude that the rock is approximately ______ billion years old.

2.6 billion years.

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

Archaea and Bacteria.

In a population with two alleles for a particular genetic locus, B and b, the allele frequency of B is 0.7. If this population is in Hardy-Weinberg equilibrium, what is the frequency of heterozygotes? What is the frequency of homozygous dominants? What is the frequency of homozygous recessives?

Bb - 0.42 BB - 0.49 bb - 0.09

Compare and contrast how the bottleneck effect and the founder effect can lead to genetic drift.

Both effects result in populations small enough for significant sampling error in the gene pool for the first few generations. A bottleneck event reduces the size of an exiting population in a given location. The founder effect occurs when a new, small population colonizes a new territory.

Which of the following is a true statement about Charles Darwin?

He proposed natural selection as the mechanism of evolution.

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

Homologies reflected a shared evolutionary history, while analogies do not. Analogies result from convergent evolution.

The animals and plants of India are almost completely different from the species in nearby Southeast Asia. Why might this be true?

India was a separate continent until relatively recently.

How did the insights of Lyell and other geologists influence Darwin's thinking about evolution?

Lyell and other geologists presented evidence for the gradual change of geologic features over millions of years. Darwin applied this idea to suggest that species evolve through the slow accumulation of small changes over long periods of time.

Distinguish between microevolution, speciation, and macroevolution.

Microevolution is a change in the gene pool of a population, often associated with adaptation. Speciation is an evolutionary process in which one species splits into two or more species. Macroevolution is evolutionary change above the species level, for example, the origin of evolutionary novelty and new taxonomic groups and the impact of mass extinctions on the diversity of life and its subsequent recovery. Macroevolution is marked by major changes in the history of life, and these changes are often noticeable enough to be evident in the fossil record.

Which of the following processes is the ultimate source of the genetic variation that serves as raw material for evolution?

Mutation.

Define fitness from an evolutionary perspective.

The fitness of an individual (or of a particular genotype) is measured by the relative number of alleles that it contributes to the gene pool of the next generation compared with the contribution of others. Thus the number of fertile offspring produced determines an individual's fitness.

Which of the following statements is (are) true about a population in Hardy-Weinberg equilibrium? (more than one may be true.)

The population is not evolving, gene flow between the population and surrounding population does not occur, and natural selection is not occurring.

As a mechanism of evolution, natural selection can be most closely equated with ______.

Unequal reproductive success.

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.

a. prezygotic b. prezygotic c. prezygotic d. prezygotic e. postzygotic

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

because a small gene pool is more likely to be changed substantially by genetic drift and natural selection.

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

exaptations.

Place these levels of classification in order from least inclusive to most inclusive: class, domain, family, genus, kingdom, order, phylum, species.

species, genus, family, order, class, phylum, kingdom, domain.

In a particular bird species, individuals with average-sized wings survive severe storms more successfully than other birds in the same population with longer or shorter wings. Of the three general outcomes of natural selection (directional, disruptive, or stabilizing), this example illustrates ______.

stabilizing selection.

Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species that lived side by side in parts of their ranges. However, recent books describe them as the eastern and western form of a single species, the yellow-rumped warbler. Apparently, the two kinds of warblers _______.

successfully interbreed.

Mass extinctions ______.

were followed by diversification of the survivors.