3. A population has a nucleotide diversity (p) of 0.08 and a neutral mutation rate of 5' 10" per generation. a) Given this information, what is the effective population size (N)? Would you expect the actual population size (N) to be larger or smaller than this number? Explain and show your work. ( Answer: b) Describe a strategy for estimating N¸ in an endangered mammal, in which capturing individuals is difficult. Then explain why estimating N. could be useful to conservation biologists Answer:

Can DNA profiling identify the source of a sample with absolute certainty? Because any two human genomes differ at about 3 million sites, no two persons (except identical twins) have the same DNA sequence. Unique identification with DNA profiling is therefore possible if enough sites of variation are examined. However, the systems used today examine only a few sites of variation. Nonetheless, even with todays technology, which uses three to five loci, a match between two DNA patterns can be considered strong evidence that the two samples came from the same source. DNA profiling in criminal cases has been a useful tool in establishing both guilt and innocence. Originally, DNA databases contained only the profiles of convicted felons. Over time, however, law enforcement agencies have expanded the collection and use of DNA profiles, and these new policies are causing controversies, once again illustrating how the availability and use of genetic technology is often ahead of consensus on how and when this technology should be used. One of these new policies is postarrest DNA collection. At this writing, 18 U.S. states as well as the federal government allow the collection of DNA samples after an arrest but before conviction. These profiles become part of the states DNA database, which is often searched for evidence in cold cases. Courts across the country have ruled for and against the use of such samples. In 2012, the Maryland Court of Appeals ruled that the collection of DNA samples from someone who has been arrested but not convicted is unconstitutional and violates an individuals right to be free from unreasonable search and seizure. The case began when a DNA sample was taken from Alonzo Jay King, Jr., who was arrested in 2009 for assault. In a database search, the DNA profile matched that taken from a 2003 unsolved rape. Based on the results of the database search, the man was sentenced to life in prison. The rape conviction was reversed, and the case was sent back to a lower court. As a result, some 16,000 DNA profiles collected postarrest but preconviction since 2009 cannot be used pending appeal of this decision. Before the court decision, postarrest DNA profiles were used in 65 arrests that resulted in 34 convictions, with an additional 12 cases pending. Supporters of postarrest DNA profiling claim that taking a DNA sample by a cheek swab is noninvasive and no different from taking someones fingerprints. Opponents claim that because DNA samples can be used to determine much more than a DNA profile, they are a threat to privacy, and that because minorities are more likely to be arrested, the practice is discriminatory. What are your thoughts on the collection and use of postarrest DNA profiles?

Can DNA profiling identify the source of a sample with absolute certainty? Because any two human genomes differ at about 3 million sites, no two persons (except identical twins) have the same DNA sequence. Unique identification with DNA profiling is therefore possible if enough sites of variation are examined. However, the systems used today examine only a few sites of variation. Nonetheless, even with todays technology, which uses three to five loci, a match between two DNA patterns can be considered strong evidence that the two samples came from the same source. DNA profiling in criminal cases has been a useful tool in establishing both guilt and innocence. Originally, DNA databases contained only the profiles of convicted felons. Over time, however, law enforcement agencies have expanded the collection and use of DNA profiles, and these new policies are causing controversies, once again illustrating how the availability and use of genetic technology is often ahead of consensus on how and when this technology should be used. One of these new policies is postarrest DNA collection. At this writing, 18 U.S. states as well as the federal government allow the collection of DNA samples after an arrest but before conviction. These profiles become part of the states DNA database, which is often searched for evidence in cold cases. Courts across the country have ruled for and against the use of such samples. In 2012, the Maryland Court of Appeals ruled that the collection of DNA samples from someone who has been arrested but not convicted is unconstitutional and violates an individuals right to be free from unreasonable search and seizure. The case began when a DNA sample was taken from Alonzo Jay King, Jr., who was arrested in 2009 for assault. In a database search, the DNA profile matched that taken from a 2003 unsolved rape. Based on the results of the database search, the man was sentenced to life in prison. The rape conviction was reversed, and the case was sent back to a lower court. As a result, some 16,000 DNA profiles collected postarrest but preconviction since 2009 cannot be used pending appeal of this decision. Before the court decision, postarrest DNA profiles were used in 65 arrests that resulted in 34 convictions, with an additional 12 cases pending. Supporters of postarrest DNA profiling claim that taking a DNA sample by a cheek swab is noninvasive and no different from taking someones fingerprints. Opponents claim that because DNA samples can be used to determine much more than a DNA profile, they are a threat to privacy, and that because minorities are more likely to be arrested, the practice is discriminatory. Would you object if you were arrested for a minor offense, such as a traffic violation, and ordered to provide a DNA sample?

Can DNA profiling identify the source of a sample with absolute certainty? Because any two human genomes differ at about 3 million sites, no two persons (except identical twins) have the same DNA sequence. Unique identification with DNA profiling is therefore possible if enough sites of variation are examined. However, the systems used today examine only a few sites of variation. Nonetheless, even with todays technology, which uses three to five loci, a match between two DNA patterns can be considered strong evidence that the two samples came from the same source. DNA profiling in criminal cases has been a useful tool in establishing both guilt and innocence. Originally, DNA databases contained only the profiles of convicted felons. Over time, however, law enforcement agencies have expanded the collection and use of DNA profiles, and these new policies are causing controversies, once again illustrating how the availability and use of genetic technology is often ahead of consensus on how and when this technology should be used. One of these new policies is postarrest DNA collection. At this writing, 18 U.S. states as well as the federal government allow the collection of DNA samples after an arrest but before conviction. These profiles become part of the states DNA database, which is often searched for evidence in cold cases. Courts across the country have ruled for and against the use of such samples. In 2012, the Maryland Court of Appeals ruled that the collection of DNA samples from someone who has been arrested but not convicted is unconstitutional and violates an individuals right to be free from unreasonable search and seizure. The case began when a DNA sample was taken from Alonzo Jay King, Jr., who was arrested in 2009 for assault. In a database search, the DNA profile matched that taken from a 2003 unsolved rape. Based on the results of the database search, the man was sentenced to life in prison. The rape conviction was reversed, and the case was sent back to a lower court. As a result, some 16,000 DNA profiles collected postarrest but preconviction since 2009 cannot be used pending appeal of this decision. Before the court decision, postarrest DNA profiles were used in 65 arrests that resulted in 34 convictions, with an additional 12 cases pending. Supporters of postarrest DNA profiling claim that taking a DNA sample by a cheek swab is noninvasive and no different from taking someones fingerprints. Opponents claim that because DNA samples can be used to determine much more than a DNA profile, they are a threat to privacy, and that because minorities are more likely to be arrested, the practice is discriminatory. What if you learned that law enforcement officials were saving the DNA sample for use in tests that might be developed in the future?

Half of the worlds population eats rice at least twice a day. Much of this rice is grown in flooded conditions, and different strains of rice are tolerant (survive) or intolerant (die) under these conditions. Rice breeders used genetic crosses to test whether tolerance to flooding is a dominant trait. Researchers used three true-breeding flood-tolerant strains, FR143, BKNFR, and Kurk, and two true-breeding flood- intolerant strains, IR42 and NB, in the crosses. Results were obtained from three sets of crosses and are reported in the Table below: Results of cross of F1 to tolerant parent: F1 plants were crossed with the tolerant parent of the cross. Number of Plants Progeny Analyzed from Intolerant Tolerant Cross Alive Dead Total 1. F2 results of cross: IR42 FR13A 187 77 264 IR42 BKNFR 192 73 265 NB Kurk 142 52 195 2. Results of cross of F1 to intolerant parent: (F1 of IR42 FR13A) IR42 14 17 31 (F1 of IR42 BKNFR) IR42 15 10 25 (F1 of NB Kurk) NB 21 35 56 3. Results of cross of F1 to tolerant parent: (F1 of IR42 FR13A) FR13A 31 0 31 (F1 of IR42 BKNFR) BKNFR 28 0 28 (F1 of NB Kurk) Kurk 40 0 40 Do the data support the hypothesis that the tolerance trait is dominant? Justify your conclusion by explaining the results from each of the three sets of crosses in terms of genotypes and phenotypic ratios. Source: T. Setter et al. 1997. Physiology and genetics of submergence tolerance in rice. Annals of Botany 79:6777.

Describe a situation in which a population would undergo the bottleneck effect and explain what impact that would have on the population’s gene pool.

Ideally, an experimental group differs from a control group (a) only with respect to the hypothesis being tested (b) because its subjects are more reliable (c) in that it is less subject to bias (d) in that it is less vulnerable to sampling error (e) only with respect to the variable being studied

How Can We Measure Allele Frequencies in Populations? The MN blood group is a single-gene, two-allele system in which each allele is codominant. Why are such codominant alleles ideal for studies of allele frequencies in a population?

For centuries, animal breeders have used artificial selection to increase the speed of racehorses. The results of such efforts are illustrated in a graph that identifies how quickly winning horses ran the 1-mile track at the Kentucky Derby, a famous race held annually at Churchill Downs, Kentucky. (The time it takes a horse to run a track of fixed length is inversely proportional to the horses speed.) Based on the data in the graph, has artificial selection increased the speed of horses consistently between 1900 and 2000? Do you think that artificial selection can increase the speed of racehorses in the future?

Which of the following populations is not in Hardy- Weinberg equilibrium? a population with 12 homozygous recessive individuals (yy), 8 homozygous dominant individuals (YY), and 4 heterozygous individuals (Yy) a population in which the allele frequencies do not change over time p2 + 2pq + q2 = 1 a population undergoing natural selection