In the Western United States, the Great Basin is a geographic feature that is home to a variety of unique species, including Great Basin bristlecone pine (Pinus longaeva, PILO). P. longaeva is well known for the age of some of the trees, some of which are over 4000 years old. In this study 17 microsatellite markers (simple sequence repeat, SSR) are identified and used to genotype a selection of 480 individuals spread across 24 PILO populations and 60 individuals divided equally between 2 outgroup species, Pinus aristata and Pinus flexilis. One population of PILO, HMW, shows more genetic similarity with P. aristata, and is included with outgroup species in the analysis. The population structure of PILO is examined and found to be weakly related to the geographic distance between populations. The population statistics Fst, Gst, Rst, Dest and an AMOVA analysis suggest that there is a substantial amount of admixture at the individual level, similar to some other species of pines. Phylogenetic trees computed using the neighbor-joining method based on the average population genetic distance and based on individual genetic distance support the population structure results and show further evidence that most of the species variation is concentrated at the individual level, rather than inside of or between species. It is possible that gene flow is still occurring, or that gene flow has occurred recently enough that the separated populations have not yet diverged from each other in a measurable way.

"A Terminal Report Submitted 31 October, 1981 on the National Science Foundation grant EAR 78-04436 with the assistance of the Department of Energy contract no. EE-78-A-28-3274"

"A Final Technical Report Submitted 31 May 1985 on the National Science Foundation grant EAR-8018687 for the period 1 April 1981 to 31 October 1984 with the assistance of the Department of Energy contract no. DE-AC02-81EV10680 covering the period 1 May 1981 to 31 October 1982" / Since Edmund Schulman’s initial interest in 1953, the Laboratory of Tree-Ring Research has conducted dendrochronological studies of bristlecone pine (Pinus longaeva D. K. Bailey, sp. Nov.) in the White Mountains of east-central California where living trees reach ages in excess of 4,000 years. The focus of this report relates to the support by the Geology and Anthropology sections in the National Science Foundation under grant EAR-8018687 for the period 1 April 1981 to 31 October 1984 with the assistance of the Department of Energy contract no. DE-AC02-81EV10680 covering the period 1 May 1981 to 31 October 1982. A summary of this research was recently published in Radiocarbon (Ferguson and Graybill 1983). In most cases various facets of the work were related to projects sponsored by all agencies. Therefore the full range of activities during that period is described herein. The primary project goals were: To extend the bristlecone pine chronology from the White Mountains of California beyond 6700 B.C. and strengthen it by incorporating additional specimens. To develop bristlecone pine chronologies in new areas for applications in archaeology, isotopic studies, and other earth sciences. To furnish dendrochronologically dated wood to researchers engaged in the study of past variations in carbon isotopes and climate.