New Estimates of the Value of Federal Mineral Rights and Land

We calculate a time series of the value of federal mineral rights in oil and natural gas by using various estimates of proven and unproven reserves and time series on federal government royalties and bonus payments. We also present estimates of the components of the revaluation of this series through time.The results are striking. Federal mineral rights are the single largest item in a complete balance sheet of the federal government, dominating the total value of tangible capital or financial assets. In 1981, for example, we estimate that the value of federal oil and gas rights exceeded $800 billion, which was larger than the privately held national debt. The paper also presents estimates of various confidence bounds on the value of oil and natural gas. The methodology can be extended to other minerals, although we have not done so; our estimate is a lower bound on the total value of all mineral rights.The paper also expands and extends previous estimates of the value of federal land. New data, and attention to the detailed decomposition of federal land holdings by type, lead to substantially larger estimates of the value of federal land than have been presented in previous research. Our estimate is that by 1981, the total value of federal land was$175 billion.

Retrotransposons Are the Major Contributors to the Expansion of the Drosophila ananassae Muller F Element

The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (>18.7 Mb) in D. ananassae. To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors to this expansion (78.6%), while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%). Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes (e.g., larger coding spans, larger introns, more coding exons, and lower codon bias), but these differences are exaggerated in D. ananassae. Compared to D. melanogaster, the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5′ ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2), while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains