Hunting during the last 200 years reduced many populations of mysticete whales to near extinction. To evaluate potential genetic bottlenecks in these exploited populations, we examined mitochondrial DNA control region sequences from 90 individual humpback whales (Megaptera novaeangliae) representing six subpopulations in three ocean basins. Comparisons of relative nucleotide and nucleotype diversity reveal an abundance of genetic variation in all but one of the oceanic subpopulations. Phylogenetic reconstruction of nucleotypes and analysis of maternal gene flow show that current genetic variation is not due to postexploitation migration between oceans but is a relic of past population variability. Calibration of the rate of control region evolution across three families of whales suggests that existing humpback whale lineages are of ancient origin. Preservation of preexploitation variation in humpback whales may be attributed to their long life-span and overlapping generations and to an effective, though perhaps not timely, international prohibition against hunting.Humpback whales (Megaptera novaeangliae) once numbered >125,000 individuals distributed into three oceanic populations: the North Pacific, the North Atlantic, and the southern oceans. Within each population, observations of migratory movement by marked individuals suggest that humpback whales form relatively discrete subpopulations that are not separated by obvious geographic barriers (1). Before protection by international agreement in 1966, the world-wide population of humpback whales had been reduced by hunting to <5000, with some regional subpopulations reduced to <200 individuals (Table 1).To evaluate the possibility that commercial hunting reduced genetic variation in baleen whales, we examined nucleotide sequence variation in the mitochondrial (mt) DNA from 90 humpback whales collected from the three major oceanic basins. We chose humpback whales for this evaluation because their well-described subpopulation divisions and well-documented history of exploitation provide a historical framework within which to evaluate genetic data (Table 1). We chose mtDNA as a genetic marker because of its power in describing the genetic structure of maternal lineages within populations and its sensitivity to demographic changes in populations (20). To allow the use of small skin samples collected by biopsy darting, we applied the polymerase chain reaction (PCR) and direct "solid-phase" sequencing methodology (21) to the mtDNA control region or "D-loop," a noncoding region that is highly variable in most vertebrates (22).The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.We first verified that oceanic populations of humpback whales are independent demographic units by estimating mtDNA gene flow with a cladistic analysis of the control region sequences. We then evaluated mtDNA diversity within each o...

The purpose of this paper is to introduce the new ASME measurement uncertainty methodology which is the basis for two new ASME/ANSI standards and the ASME short course of the same name. Some background and history that led to the selection of this methodology are discussed as well as its application in current SAE, ISA, JANNAF, NRC, USAF, NATO, and ISO Standards documents and short courses. This ASME methodology is rapidly becoming the national and international standard.

The genetic structure of humpback whale populations and subpopulation divisions is described by restriction fragment length analysis of the mitochondrial (mt) DNA from samples of 230 whales collected by biopsy darting in 11 seasonal habitats representing six subpopulations, or 'stocks', world-wide. The hierarchical structure of mtDNA haplotype diversity among population subdivisions is described using the analysis of molecular variance (AMOVA) procedure, the analysis of gene identity, and the genealogical relationship of haplotypes as constructed by parsimony analysis and distance clustering. These analyses revealed: (i) significant partitioning of world-wide genetic variation among oceanic populations, among subpopulations or 'stocks' within oceanic populations and among seasonal habitats within stocks; (ii) fixed categorical segregation of haplotypes on the south-eastern Alaska and central California feeding grounds of the North Pacific; (iii) support for the division of the North Pacific population into a central stock which feeds in Alaska and winters in Hawaii, and an eastern or 'American' stock which feeds along the coast of California and winters near Mexico; (iv) evidence of genetic heterogeneity within the Gulf of Maine feeding grounds and among the sampled feeding and breeding grounds of the western North Atlantic; and (v) support for the historical division between the Group IV (Western Australia) and Group V (eastern Australia, New Zealand and Tonga) stocks in the Southern Oceans. Overall, our results demonstrate a striking degree of genetic structure both within and between oceanic populations of humpback whales, despite the nearly unlimited migratory potential of this species. We suggest that the humpback whale is a suitable demographic and genetic model for the management of less tractable species of baleen whales and for the general study of gene flow among long-lived, mobile vertebrates in the marine ecosystem.

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