Papers by Kelly Robertson
Currently, six stocks of harbor porpoise are recognized in the Pacific Stock Assessment Reports: ... more Currently, six stocks of harbor porpoise are recognized in the Pacific Stock Assessment Reports: Morro Bay, Monterey Bay, San Francisco-Russian River, Northern California/Southern Oregon, Oregon/Washington Coast, and Washington Inland Water stocks. The current stock boundaries were identified primarily as a result of a genetic study published in 2002, which provided evidence for relatively fine-scale structure of demographically independent stocks. In the published study, the Oregon/Washington Coast and Washington Inland Water stock boundary at Cape Flattery was supported by the genetic analyses, but stock structure along the Oregon/Washington Coast was unresolved because sample sizes for the genetic study were limited, and similarly, data about animal distribution and density along the Oregon/Washington coast were limited. Sample collection efforts continued after publication of the 2002 paper to increase sample size overall and to collect samples from previously unrepresented area...
Bactrocera correcta is one of the most destructive pests of horticultural crops in tropical and s... more Bactrocera correcta is one of the most destructive pests of horticultural crops in tropical and subtropical regions. Despite the economic risk, the population genetics of this pest have remained relatively unexplored. This study explores population genetic structure and contemporary gene flow in B. correcta in Chinese Yunnan Province and attempts to place observed patterns within the broader geographical context of the species' total range. Based on combined data from mtDNA cox1 sequences and 12 microsatellite loci obtained from 793 individuals located in 7 countries, overall genetic structuring was low. The expansion history of this species, including likely human-mediated dispersal, may have played a role in shaping the observed weak structure. The study suggested a close relationship between Yunnan Province and adjacent countries, with evidence for Western and/or Southern Yunnan as the invasive origin of B. correcta within Yunnan Province. The information gleaned from this analysis of gene flow and population structure has broad implications for quarantine, trade and management of this pest, especially in China where it is expanding northward. Future studies should concentrate effort on sampling South Asian populations, which would enable better inferences of the ancestral location of B. correcta and its invasion history into and throughout Asia. Bactrocera correcta (Bezzi) (Diptera: Tephritidae), the guava fruit fly, is one of the most destructive pests of many tropical and subtropical fruits and vegetables, such as guavas, mangoes, citruses, melons and chili peppers, causing production losses and quality degradation 1,2 . Considering that the species has a broad host range, is highly adaptable, and has a high reproductive ability and dispersal capacity , it has been regulated as a quarantine pest by many countries, including China 1,5 . Bactrocera correcta was first reported in Bihar, India in 1916 6 , where it is thought to have originally diverged from its common ancestor . At present, it is distributed throughout South and East Asia, from Bhutan in the west to China and Vietnam in the east . The species has been recorded in the United States, where it was first detected in California in 1986, but has not yet established due to timely prevention and control measures 13 . In China, B. correcta was first discovered in the Yunnan Province (Yuanjiang and Mosha) in 1982 14 , and the infestation of this fly has become more entrenched in Yunnan in recent years . Yunnan is located in southwest China, adjacent to Myanmar, Laos and Vietnam, from which entry of exotic species into Yunnan has been facilitated by similar environmental conditions 4 . As such, Yunnan is considered
Marine Mammal Science, 2021
Commonly, teachers provide learning evaluation in the form of questions about the learning materi... more Commonly, teachers provide learning evaluation in the form of questions about the learning materials. Nonetheless teachers only performs the final score without analyzing the achievement of students' cognitive level on the material and do not inform it to students as well. The cognitive level of students can be classified based on Bloom's Taxonomy. In addition, the cognitive level of the test does not base on Bloom's taxonomy, but it is made for students to get good score only, it does not consider if the cognitive level is low. This study aims to describe the analysis of the students cognitive level distribution about Projectile Motion. The analyzed cognitive level consists of C1 (knowledge), C2 (comprehension), C3 (application), and C4 (analysis). The test results are classified based on the cognitive levels of C1-C4 according to students' score in Projectile Motion. For easier reading it, Venn Diagram is used to perform the distribution of students' cognitive level. The respondents of this research are 100 Physics, Physics Education, Mathematics and Mathematics Education sophomers of UKSW. The result of this study shows that there is distribution of students cognitive level from C1 to C4 in the form of Venn Diagram.
SUMMARYRuns of homozygosity (ROH) occur when offspring receive the same ancestral haplotype from ... more SUMMARYRuns of homozygosity (ROH) occur when offspring receive the same ancestral haplotype from both parents, and, accordingly, reduce individual heterozygosity. Their distribution throughout the genome contains information on the probability of inbreeding mediated by mating system and population demography. Here, we investigate variation in killer whale demographic history as reflected in genome-wide heterozygosity, using a global dataset of 26 genomes. We find an overall pattern of lower heterozygosity in genomes sampled at high latitudes, with hundreds of short ROH (< 1Mbp) reflecting high background relatedness due to coalescence of haplotypes during bottlenecks associated with founder events during post-glacial range expansions. Across most of the species’ range, intermediate length ROH (1-10Mb) revealed long-term inbreeding in 22 of the 26 sampled killer whale genomes, consistent with the high social philopatry observed in all populations studied to date. Inbreeding coeffi...
Biology Letters, 2010
The North Pacific right whale ( Eubalaena japonica ) was heavily exploited by both nineteenth cen... more The North Pacific right whale ( Eubalaena japonica ) was heavily exploited by both nineteenth century whaling and recent (1960s) illegal Soviet catches. Today, the species remains extremely rare especially in the eastern North Pacific. Here, we use photographic and genotype data to calculate the first mark–recapture estimates of abundance for right whales in the Bering Sea and Aleutian Islands. The estimates were very similar: photographic = 31 (95% CL 23–54), genotyping = 28 (95% CL 24–42). We also estimated the population contains eight females (95% CL 7–18) and 20 males (95% CL 17–37). Although these estimates may relate to a Bering Sea subpopulation, other data suggest that the total eastern North Pacific population is unlikely to be much larger. Its precarious status today—the world's smallest whale population for which an abundance estimate exists—is a direct consequence of uncontrolled and illegal whaling, and highlights the past failure of international management to pre...
Marine Mammal Science, 2012
Two species of bottlenose dolphins are currently recognized by most cetologists: the pan-tropical... more Two species of bottlenose dolphins are currently recognized by most cetologists: the pan-tropical and temperate Tursiops truncatus and the endemic Indo-Pacific T. aduncus. The latter was described from a specimen from the Red Sea, with nothing in the description that would allow referral of the specimen to one or the other of the two species. Because both species occur in the northern Indian Ocean, it was possible that the holotype specimen was actually a common bottlenose dolphin, not of the Indo-Pacific species. The holotype skull was thought lost but has been found in the Berlin Museum. We describe the skull and examine its affinities through comparison of a partial mtDNA control-region sequence with sequences from South Africa and through application of classification functions from a discriminant analysis of the two putative species from Taiwan. The mtDNA sequence is identical to that of South African specimens referred to the Indo-Pacific species, and the multivariate likelihood assignment associates the skull with Taiwanese specimens referred to that species. These results ensure the correctness of use of the name T. aduncus for the species.
We describe a modification to the most common method of preparing sperm whale teeth for age deter... more We describe a modification to the most common method of preparing sperm whale teeth for age determination. The first mandibular or nearest straightest tooth was sectioned in half with a slow-rotating band saw, polished and, rather than subjecting the section ed tooth to 10% formic acid for 30 hours, etched in 15% formic acid. The exposure time of each tooth to the acid varied depending on the size, and especially, the density of the tooth. Clear, well defined growth layer groups in sperm whale teeth suitable for age determinati on can be produced in substantially shorter periods of time. A method for the preparation of teeth from young sperm whales is also descri bed. Thin sectioning and staining of teeth is used to prepare small teeth from young animals and avoids potential decalcification, which may possibly occur using acid etching methods.
Reconstruction of the demographic and evolutionary history of populations assuming a consensus tr... more Reconstruction of the demographic and evolutionary history of populations assuming a consensus tree-like relationship can mask more complex scenarios, which are prevalent in nature. An emerging genomic toolset, which has been most comprehensively harnessed in the reconstruction of human evolutionary history, enables molecular ecologists to elucidate complex population histories. Killer whales have limited extrinsic barriers to dispersal and have radiated globally, and are therefore a good candidate model for the application of such tools. Here, we analyse a global dataset of killer whale genomes in a rare attempt to elucidate global population structure in a non-human species. We identify a pattern of genetic homogenisation at lower latitudes and the greatest differentiation at high latitudes, even between currently sympatric lineages. The processes underlying the major axis of structure include high drift at the edge of species' range, likely associated with founder effects and...
Conservation Genetics Resources
Nature communications, May 31, 2016
Analysing population genomic data from killer whale ecotypes, which we estimate have globally rad... more Analysing population genomic data from killer whale ecotypes, which we estimate have globally radiated within less than 250,000 years, we show that genetic structuring including the segregation of potentially functional alleles is associated with socially inherited ecological niche. Reconstruction of ancestral demographic history revealed bottlenecks during founder events, likely promoting ecological divergence and genetic drift resulting in a wide range of genome-wide differentiation between pairs of allopatric and sympatric ecotypes. Functional enrichment analyses provided evidence for regional genomic divergence associated with habitat, dietary preferences and post-zygotic reproductive isolation. Our findings are consistent with expansion of small founder groups into novel niches by an initial plastic behavioural response, perpetuated by social learning imposing an altered natural selection regime. The study constitutes an important step towards an understanding of the complex in...
Molecular Ecology Notes, 2007
Molecular Ecology Resources, 2011
Marine Mammal Science, 2005
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Papers by Kelly Robertson