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Population structure is influenced by extrinsic factors, such as landscape architecture and dispersal barriers. Lotic network architecture is known to constrain ecological, demographic and evolutionary processes, including population genetic structure. I assessed the population structure of a widespread aquatic salamander, Necturus maculosus, across three river basins in central and eastern Kentucky. I examined the role of network architecture, anthropogenic barriers, and spatial scale on patterns of population structure. I also provided a review of N. maculosus capture methods and offer an improved trap design. I identified significant structuring between the combined Licking/Kinniconick basin and the Kentucky River basin, with further structure within each basin. I found evidence for both hierarchically organized populations structure (e.g. Stream Hierarchy Model), as well as population structure unaffected by network hierarchy (e.g. Death Valley Model). These results highlight the importance of scale when examining population structure. Whereas one model may suffice to explain population structure at a local scale, a second model may be necessary to accurately describe the population structure across larger spatial scales. These results suggest that local factors affect population structure uniquely across a species’ range, and support a multi-model approach for assessing population structure.

Queixadas (Tayassu pecari) são mamíferos ungulados sociais que vivem em bandos que facilmente ultrapassam 100 indivíduos. Os objetivos do presente estudo foram: 1) avaliar se há relação entre o parentesco e a estrutura social das queixadas e 2) re-analisar se há diferenciação genética entre queixadas de duas localidades do Pantanal do Mato Grosso do Sul, utilizando maior amostragem de indivíduos e de marcadores microssatélites. Foram genotipadas 184 amostras de queixadas (53 da Fazendo Rio Negro, RN e 131 da Fazenda Santa Emília, SE) para 15 microssatélites. O número de alelos encontrados variou de 2 a 12, com média de 4,60 em RN e 5,07 em SE. Embora o número de alelos médio foi significativamente maior em SE do que em RN (p < 0,05), a riqueza alélica média (4,59 na RN e 4,69 na SE) e as heterozigosidades médias observada e esperada (0,50 e 0,53 na RN e 0,55 e 0,55 na SE, respectivamente) foram similares em ambas as localidades, (p > 0,05). A mediana do coeficiente de parentesco em ambas as localidades foi significativamente maior entre os indivíduos de mesmo grupo de coleta do que entre os indivíduos de grupos de coleta diferentes, tanto para a análise incluindo todos os indivíduos como para a análise sem os indivíduos jovens. Isso sugere que tal resultado não é influenciado por possível captura de um jovem com seu progenitor. De forma similar, a mediana do coeficiente de parentesco considerando o sexo dos indivíduos (macho/macho, macho/fêmea e fêmea/fêmea) dentro e entre os grupos de coleta foi significativamente maior entre as categorias dentro dos grupos de coleta do que entre os grupos de coleta, tanto com os indivíduos jovens como sem os indivíduos jovens. Tais resultados sugerem que o parentesco possui influência na formação dos grupos sociais. O valor de FST encontrado entre as localidades foi de 0,017 e significativamente diferente de zero e o valor de DEST foi de 0,015. A análise Bayesiana, assumindo o modelo de mistura entre as populações e frequências alélicas correlacionadas, apontou o valor de K=1 como sendo o mais provável. Quando a localidade de coleta foi informada, o valor de K mais provável foi de 2 e os agrupamentos corresponderam exatamente às localidades amostradas. Esses resultados indicam que as queixadas das duas localidades estudadas compõem duas populações com alto fluxo gênico entre elas / White-lipped peccaries (Tayassu pecari) are social ungulates that live in herds of usually more than 100 individuals. The aims of the present study were: 1) to evaluate whether there is any correlation between relatedness and social structure of white-lipped peccaries and 2) to re-examine whether there is significant genetic differentiation in white-lipped peccaries from two adjacent locations of the Brazilian Pantanal, based on a larger sample of individuals and of microsatellite markers. In total, 184 peccaries (53 from Fazenda Rio Negro, RN and 131 from Fazenda Santa Emilia, SE) were genotyped for 15 microsatellites. The number of alleles observed per microsatellite varied from 2 to 12, with a mean of 4.60 in RN and 5.07 in SE. Although the mean number of alleles was significantly higher in SE than in RN (p < 0.05), the mean allelic richness (4.59 in RN and 4.69 in SE) and mean observed and expected heterozygosities (0.50 and 0.53 in RN and 0.55 and 0.55 in SE, respectively) were similar in both locations (p > 0,05). The median of the coefficient of relatedness in both locations was significantly higher between individuals captured together than between individuals from different capture groups, both for the analyses including all individuals as for the analyses without the youngsters. This suggests that this result is not influenced by the possible capture of a young with its parent. Similarly, the median of the coefficient of relatedness according to gender (male vs. male, male vs. female, and female vs. female) was significantly higher within than among capture groups, including or excluding young individuals. Those results suggest that relatedness has some importance in the social structure of white-lipped peccaries. The FST between the locations was 0.017 and significantly different from zero and the DEST was 0.015. The Bayesian analysis, assuming the model of population mixture and correlated allele frequencies, showed that the most likely K was 1. When the collection site was included in the analysis, the most likely value of K was 2 and the clusters corresponded exactly to the locations of origin of the samples. Those results suggest that the white-lipped peccaries of the two sites studied comprise two populations with high levels of gene flow between them

Seeking for a sustainable exploitation of the populations of commercialy valuable fish species without causing danger to their genetic resources it is necessary to amass extensive data about the population genetic structure of this fish species. When preparing the thesis a total of 221 eels and 262 perch were analysed. Fish samples collected in Lithuania and Latvia were studied using microsatellite DNA, the mtDNA D-loop region and mtDNA cyt b markers. Original primer pairs Ang1 and Ang2 have been designed for the mtDNA analysis of the eel. On the basis of the Anguilla genus species mtDNA D-loop region data obtained during work it can be stated that inland and territorial water bodies of Lithuania contain no A. japonica and A. rostrata species. The molecular investigations carried out indicate that the population genetic structure of the European eel is characterized by the genetic mosaic, which is formed due to the existence of reproductively isolated groups. Statistically significant genetic differentiation between the eel groups naturally recruited to Lithuania and Latvia and introduced to Lithuanian lakes has not been determined (p > 0.05). However, the eels stocked into different lakes of Lithuania differ in their genetic diversity. Pairwise comparisons of the Lithuanian and Latvian perch populations based on the mtDNA D-loop region data revealed that the perch population of Lake Drūkšiai was statistically significantly (p < 0.05) different from all other perch... [to full text] / Siekiant tvariai eksploatuoti verslinių žuvų populiacijas nesukeliant pavojaus jų genetiniams resursams būtina sukaupti daug duomenų apie šių rūšių populiacinę-genetinę struktūrą. Iš viso tyrimams panaudoti 221 unguriai ir 262 ešeriai. Lietuvoje ir Latvijoje surinkti žuvų audinių pavyzdžiai tirti naudojant mikrosatelitinės DNR, mtDNR D-kilpos regiono ir mtDNR cyt b žymenis. Ungurių mtDNR analizei sukurtos originalios Ang1 ir Ang2 pradmenų poros. Remiantis disertacinio darbo metu atliktais Anguilla genties rūšių mtDNR D-kilpos regiono tyrimais, galima teigti, jog šiuo metu A. japonica ir A. rostrata rūšių, tiek tirtuose Lietuvos vidaus vandens telkiniuose, tiek Lietuvos teritoriniuose vandenyse nėra. Atlikti molekuliniai tyrimai rodo, kad europinio upinio ungurio populiacinė-genetinė struktūra pasižymi genetine mozaika, kurios susiformavimą lemia reproduktyviai izoliuotos grupės. Tarp natūraliai į Lietuvą ir Latviją atplaukusių ir introdukuotų Lietuvos ežeruose ungurių grupių statistiškai patikima genetinė diferenciacija nenustatyta (p > 0,05), tačiau skirtinguose Lietuvos ežeruose gyvenantys unguriai pasižymi skirtinga genetine įvairove. Atliktų Perca fluviatilis mtDNR D-kilpos regiono tyrimų rezultatai rodo, jog Drūkšių ežero ešerių populiacija statistiškai patikimai (p < 0,05) skiriasi nuo visų kitų Lietuvos ir Latvijos ešerių populiacijų. Nustatyta, kad nuo Lietuvos pietvakarinės dalies iki Latvijos centrinės dalies plyti kelių skirtingų ešerių genetinių linijų kontaktinė... [toliau žr. visą tekstą]

Siekiant tvariai eksploatuoti verslinių žuvų populiacijas nesukeliant pavojaus jų genetiniams resursams būtina sukaupti daug duomenų apie šių rūšių populiacinę-genetinę struktūrą. Iš viso tyrimams panaudoti 221 unguriai ir 262 ešeriai. Lietuvoje ir Latvijoje surinkti žuvų audinių pavyzdžiai tirti naudojant mikrosatelitinės DNR, mtDNR D-kilpos regiono ir mtDNR cyt b žymenis. Ungurių mtDNR analizei sukurtos originalios Ang1 ir Ang2 pradmenų poros. Remiantis disertacinio darbo metu atliktais Anguilla genties rūšių mtDNR D-kilpos regiono tyrimais, galima teigti, jog šiuo metu A. japonica ir A. rostrata rūšių, tiek tirtuose Lietuvos vidaus vandens telkiniuose, tiek Lietuvos teritoriniuose vandenyse nėra. Atlikti molekuliniai tyrimai rodo, kad europinio upinio ungurio populiacinė-genetinė struktūra pasižymi genetine mozaika, kurios susiformavimą lemia reproduktyviai izoliuotos grupės. Tarp natūraliai į Lietuvą ir Latviją atplaukusių ir introdukuotų Lietuvos ežeruose ungurių grupių statistiškai patikima genetinė diferenciacija nenustatyta (p > 0,05), tačiau skirtinguose Lietuvos ežeruose gyvenantys unguriai pasižymi skirtinga genetine įvairove. Atliktų Perca fluviatilis mtDNR D-kilpos regiono tyrimų rezultatai rodo, jog Drūkšių ežero ešerių populiacija statistiškai patikimai (p < 0,05) skiriasi nuo visų kitų Lietuvos ir Latvijos ešerių populiacijų. Nustatyta, kad nuo Lietuvos pietvakarinės dalies iki Latvijos centrinės dalies plyti kelių skirtingų ešerių genetinių linijų kontaktinė... [toliau žr. visą tekstą] / Seeking for a sustainable exploitation of the populations of commercialy valuable fish species without causing danger to their genetic resources it is necessary to amass extensive data about the population genetic structure of this fish species. When preparing the thesis a total of 221 eels and 262 perch were analysed. Fish samples collected in Lithuania and Latvia were studied using microsatellite DNA, the mtDNA D-loop region and mtDNA cyt b markers. Original primer pairs Ang1 and Ang2 have been designed for the mtDNA analysis of the eel. On the basis of the Anguilla genus species mtDNA D-loop region data obtained during work it can be stated that inland and territorial water bodies of Lithuania contain no A. japonica and A. rostrata species. The molecular investigations carried out indicate that the population genetic structure of the European eel is characterized by the genetic mosaic, which is formed due to the existence of reproductively isolated groups. Statistically significant genetic differentiation between the eel groups naturally recruited to Lithuania and Latvia and introduced to Lithuanian lakes has not been determined (p > 0.05). However, the eels stocked into different lakes of Lithuania differ in their genetic diversity. Pairwise comparisons of the Lithuanian and Latvian perch populations based on the mtDNA D-loop region data revealed that the perch population of Lake Drūkšiai was statistically significantly (p < 0.05) different from all other perch... [to full text]

Migration acts as a selective force on the ecology and evolutionary trajectory of species, as well as presenting fundamental challenges for conservation. My thesis examines the impact of migration by exploring patterns of differentiation among and within migratory and non-migratory populations of the Loggerhead Shrike (Lanius ludovicianus). First, I use morphological, genotypic, stable isotope and leg band recovery data to quantify migratory connectivity in the species. Comparison across markers reveals a generally concordant pattern of moderate connectivity to the Gulf Coast, but overall mixing among populations on the wintering grounds. Combining data from multiple markers in a Bayesian framework improves the resolution of assignment of wintering birds to a breeding ground origin. Information on the species’ migratory patterns provides an explicit framework for interpreting patterns of genetic and ecological variation. I test two hypotheses regarding the interaction of gene flow and migratory habit: (1) migration facilitates gene flow; and (2) gene flow will occur most often along the axis of migration. Genetic population structure in migratory populations is weaker than in non-migratory populations, with gene flow facilitated by dispersal movements of females and first year breeders. As predicted, gene flow occurs most often along the north-south axis of migration, likely due either to opportunistic settling of dispersers or potentially, pairing on the wintering grounds. I investigate variation in the extent and scheduling of moult in relation to underlying genetic differences among populations, age, sex, body size, food availability and migratory habit. I find a pattern of interrupted moult across migratory populations, which may represent a trade-off between time allocated to breeding versus molt and migration. Loggerhead Shrikes in eastern and more southerly migratory populations undergo a greater extent of their moult on the breeding grounds and non-migratory individuals undergo a more extensive pre-formative moult than migratory individuals. I interpret this as suggesting a trade-off between resources allocated to molt versus those required for reproduction. / Thesis (Ph.D, Biology) -- Queen's University, 2011-01-25 15:54:36.593

Made available in DSpace on 2014-06-11T19:32:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-08-22Bitstream added on 2014-06-13T19:42:39Z : No. of bitstreams: 1 cavallari_mm_dr_botib.pdf: 2341412 bytes, checksum: 25cb49e35e82d3a208a4d24cb3f50d39 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O presente trabalho teve como objetivo produzir ferramentas e informações úteis para a conservação e exploração racional de Casearia sylvestris Sw. (Salicaceae), uma espécie que produz diterpenos clerodânicos de grande importância farmacológica (casearinas), e que é explorada por extrativismo. Tal objetivo foi alcançado através do desenvolvimento de marcadores microssatélites específicos para C. sylvestris e de um estudo da diversidade genética e química existente entre e dentro de populações do Estado de São Paulo. Tradicionalmente são reconhecidas duas variedades em C. sylvestris (var. sylvestris e var. lingua), o que é motivo de debate devido à existência de formas intermediárias. Este trabalho objetivou, adicionalmente, contribuir com argumentos genéticos para esta discussão. Foi construída uma biblioteca enriquecida em microssatélites, a partir da qual obtiveram-se e validaram-se dez pares de iniciadores (primers) microssatélites específicos para C. sylvestris. Estes pares de iniciadores foram utilizados para o estudo da estrutura genética de populações de C. sylvestris através da amostragem de 376 indivíduos em nove populações distribuídas em quatro ecossistemas (Floresta Ombrófila Densa, Floresta Estacional Semidecidual, Cerrado e ecótonos). As duas variedades foram amostradas de acordo com sua distribuição nestes ecossistemas. A genotipagem dos indivíduos para os locos amostrados foi realizada através de eletroforese em gel de acrilamida lido a 700 e 800 nm por um seqüenciador IR2-DNA Analyser (LI-COR). Os dados foram analisados através de abordagens frequentistas, bayesianas e baseadas na teoria de coalescência, utilizando-se diversos programas computacionais. Para o estudo da diversidade química, as mesmas populações foram amostradas, selecionando-se 12 indivíduos por população, totalizando 108 indivíduos. Adicionalmente, foram... / This work aimed obtaining tools and information for the conservation and rational exploitation of Casearia sylvestris Sw. (Salicaceae), a tree species which produces casearins, pharmacologically important clerodane diterpenes. This goal was achieved through the development of a set of polymorphic microsatellite markers, and through the study of chemical and genetic diversity in populations of C. sylvestris from São Paulo State. Also, we aimed contributing for the debate on the existence of two varieties within this species (var. sylvestris e var. lingua). A genomic library was constructed and 10 primer pairs were obtained. Those primers were utilized for a population genetic structure analysis, in which 376 individuals from nine populations distributed on four different ecosystems (Evergreen Atlantic Forest, Semideciduous Atlantic Forest, Cerrado and ecotones) were sampled. The two varieties were sampled according to its distribution among these populations. Genotyping was performed at 700 and 800 nm by electrophoresis on an IR2-DNA Analyser (LI-COR). The data were analyzed through frequentist, Bayesian and coalescence-based approaches, through the use of several softwares. Chemical diversity was studied by sampling in the same populations (12 individuals per population, i.e. 108 individuals). Also, cuttings of these individuals were prepared, aiming to verify its’ chemical compounds after a year of green-house cultivation. Cuttings’ rooting was problematic and a methodology was developed. Only 46 cuttings survived. Casearins from these 154 individuals (108 + 46) were extracted and analyzed by HPLC. Genetic analysis results suggests a partial genome duplication, as more than two alleles for the same locus were observed in 8% of var. sylvestris individuals and in 70% of var. lingua individuals. Additional studies are necessary to verify the hypothesis of partial genome duplication... (Complete abstract click electronic access below)

Queixadas (Tayassu pecari) são mamíferos ungulados sociais que vivem em bandos que facilmente ultrapassam 100 indivíduos. Os objetivos do presente estudo foram: 1) avaliar se há relação entre o parentesco e a estrutura social das queixadas e 2) re-analisar se há diferenciação genética entre queixadas de duas localidades do Pantanal do Mato Grosso do Sul, utilizando maior amostragem de indivíduos e de marcadores microssatélites. Foram genotipadas 184 amostras de queixadas (53 da Fazendo Rio Negro, RN e 131 da Fazenda Santa Emília, SE) para 15 microssatélites. O número de alelos encontrados variou de 2 a 12, com média de 4,60 em RN e 5,07 em SE. Embora o número de alelos médio foi significativamente maior em SE do que em RN (p < 0,05), a riqueza alélica média (4,59 na RN e 4,69 na SE) e as heterozigosidades médias observada e esperada (0,50 e 0,53 na RN e 0,55 e 0,55 na SE, respectivamente) foram similares em ambas as localidades, (p > 0,05). A mediana do coeficiente de parentesco em ambas as localidades foi significativamente maior entre os indivíduos de mesmo grupo de coleta do que entre os indivíduos de grupos de coleta diferentes, tanto para a análise incluindo todos os indivíduos como para a análise sem os indivíduos jovens. Isso sugere que tal resultado não é influenciado por possível captura de um jovem com seu progenitor. De forma similar, a mediana do coeficiente de parentesco considerando o sexo dos indivíduos (macho/macho, macho/fêmea e fêmea/fêmea) dentro e entre os grupos de coleta foi significativamente maior entre as categorias dentro dos grupos de coleta do que entre os grupos de coleta, tanto com os indivíduos jovens como sem os indivíduos jovens. Tais resultados sugerem que o parentesco possui influência na formação dos grupos sociais. O valor de FST encontrado entre as localidades foi de 0,017 e significativamente diferente de zero e o valor de DEST foi de 0,015. A análise Bayesiana, assumindo o modelo de mistura entre as populações e frequências alélicas correlacionadas, apontou o valor de K=1 como sendo o mais provável. Quando a localidade de coleta foi informada, o valor de K mais provável foi de 2 e os agrupamentos corresponderam exatamente às localidades amostradas. Esses resultados indicam que as queixadas das duas localidades estudadas compõem duas populações com alto fluxo gênico entre elas / White-lipped peccaries (Tayassu pecari) are social ungulates that live in herds of usually more than 100 individuals. The aims of the present study were: 1) to evaluate whether there is any correlation between relatedness and social structure of white-lipped peccaries and 2) to re-examine whether there is significant genetic differentiation in white-lipped peccaries from two adjacent locations of the Brazilian Pantanal, based on a larger sample of individuals and of microsatellite markers. In total, 184 peccaries (53 from Fazenda Rio Negro, RN and 131 from Fazenda Santa Emilia, SE) were genotyped for 15 microsatellites. The number of alleles observed per microsatellite varied from 2 to 12, with a mean of 4.60 in RN and 5.07 in SE. Although the mean number of alleles was significantly higher in SE than in RN (p < 0.05), the mean allelic richness (4.59 in RN and 4.69 in SE) and mean observed and expected heterozygosities (0.50 and 0.53 in RN and 0.55 and 0.55 in SE, respectively) were similar in both locations (p > 0,05). The median of the coefficient of relatedness in both locations was significantly higher between individuals captured together than between individuals from different capture groups, both for the analyses including all individuals as for the analyses without the youngsters. This suggests that this result is not influenced by the possible capture of a young with its parent. Similarly, the median of the coefficient of relatedness according to gender (male vs. male, male vs. female, and female vs. female) was significantly higher within than among capture groups, including or excluding young individuals. Those results suggest that relatedness has some importance in the social structure of white-lipped peccaries. The FST between the locations was 0.017 and significantly different from zero and the DEST was 0.015. The Bayesian analysis, assuming the model of population mixture and correlated allele frequencies, showed that the most likely K was 1. When the collection site was included in the analysis, the most likely value of K was 2 and the clusters corresponded exactly to the locations of origin of the samples. Those results suggest that the white-lipped peccaries of the two sites studied comprise two populations with high levels of gene flow between them

Abstract Tigers are endangered in the wild and face increasing threats from habitat loss and fragmentation. The majority of their range occurs in the Indian subcontinent, which is therefore a critical area for tiger conservation. Bengal tigers are distributed across many small protected areas in India. Two important Bengal tiger landscapes &#8212; Terai Arc Landscape (TAL) and Sundarbans in India were lacking in basic genetic information and needed to address the impact of anthropogenic pressure and climate change on their genetic makeup in order to identify conservation units. Therefore, I employed nuclear and mitochondrial genetic markers on TAL and Sundarbans tiger individuals to respond these demands for the first time. Thirty-nine heterologous microsatellite loci were screened on Bengal tigers and thirteen of these loci were selected to genotype Bengal tiger samples from western TAL (WTAL) and Sundarbans. After I had genotyped seventy-one Bengal tiger individuals from WTAL, I found cryptic population genetic structure, moderate gene flow and asymmetric migration among the subpopulation. Genetic diversity was moderate and there were no signs of population bottlenecks. In order to maintain the connectivity of subpopulations and avoid human&#8212;wildlife conflict, relocation of villages is necessary. Preventive measures against habitat encroachment and a ban on sand and boulder mining in the corridor area should also be implemented. Noninvasively-collected tiger samples from Sundarbans were analyzed for mitochondrial and microsatellite markers and compared with mainland (northern and peninsular) Bengal tiger populations in India. Sundarbans tigers were found to be genetically distinct and had lower genetic variation in comparison to other mainland tiger populations. Demographic analysis indicated recent historical isolation (600&#8212;2000 years ago) of the Sundarbans tiger from the mainland. Both historical and genetic evidence supported that the Sundarbans tiger was genetically connected to other mainland tigers until recently. Conclusively, genetic isolation from the mainland tiger population and adaptation to the mangrove ecosystem might have jointly shaped the genetic architecture of the Sundarbans tiger. Hence, the Sundarbans tiger needs special conservation attention for the preservation of its unique ability to adapt and for its genetic individuality. It should be managed as an evolutionary significant unit (ESU) under the adaptive evolutionary conservation (AEC) criteria. I also addressed a problem in the previously suggested sex-specific gene flow estimation method and recommended an alternative approach for a more precise estimation. / Tiivistelmä Tiikeri on nykyisin uhanalainen lajin elinympäristön supistumisen ja pilkkoutumisen vuoksi. Lajin tärkein esiintymisalue on Intian niemimaalla, joka on siten kriittisen tärkeä alue tiikerin suojelun kannalta. Intiantiikereitä esiintyy useilla pienillä suojelualueilla Intiassa. Kaksi tärkeää tiikerin esiintymisaluetta Intiassa ovat Terain kaaren (TAL) alue luoteis-Intiassa sekä Sundarbansin mangrovealue Bangladeshin rajalla. Näiden alueiden tiikereistä ei ole ollut olemassa geneettistä perustietoutta, jota tarvitaan, kun arvioidaan ihmisen toiminnan ja ilmastonmuutoksen aiheuttamia muutoksia tiikeripopulaatioiden geneettisessä koostumuksessa sekä kun määritellään lajin suojelun kannalta merkittäviä luonnonsuojeluyksikköjä. Tässä väitöskirjatutkimuksessa tutkittiin Terain kaaren ja Sundarbansin alueen tiikereiden geneettistä monimuotoisuutta ja rakennetta sekä tuman että mitokondrion geenimerkkien avulla. Tutkimuksessa selvitettiin kolmenkymmenyhdeksän tuman geenimerkin (mikrosatelliitin) soveltuvuutta intiantiikerin geneettisiin tutkimuksiin, ja näistä valittiin kolmetoista käytettäväksi läntisen Terain kaaren ja Sundarbansin alueiden tiikereiden geneettisiin tutkimuksiin. Terain kaaren alueelta tutkittiin seitsemänkymmenentäyksi intiantiikerinäytettä. Tulosten perusteella alueella on aikaisemmin havaitsematonta kryptistä populaatiorakennetta. Geenivirtaa eri alapopulaatioiden välillä oli kohtuullisen paljon, mutta se oli epäsymmetristä. Tiikereiden geneettinen monimuotoisuus oli melko suurta eikä geneettisillä menetelmillä havaittu eri alapopulaatioissa merkkejä populaation koon pullonkauloista. Jotta alapopulaatioiden välinen yhdistyneisyys säilyisi jatkossa, joidenkin kylien siirto toisaalle on välttämätöntä. Ihmisten luvaton levittäytyminen tiikerin elinalueita yhdistävillä käytävillä täytyisi saada hallintaan sekä kieltää hiekanotto ja kivenlouhinta. Sundarbansin alueelta ei-invasiivisesti kerätyt tiikerinäytteet tutkittiin sekä tuman että mitokondrion merkkigeenillä ja alueen tiikereiden geneettistä koostumusta verrattiin manner-Intian tiikeripopulaatioiden koostumukseen. Sundarbansin tiikereiden todettiin poikkeavan geneettisesti manneralueen tiikeripopulaatioista ja niiden geneettinen monimuotoisuus oli alhaisempaa kuin manneralueella. Koalesenssisimulaatiohin perustava demografinen analyysi viittasi Sundarbansin tiikereiden suhteellisen viimeaikaiseen (600&#8212;2000 vuotta sitten) erkanemiseen manneralueen tiikereistä. Sekä historialliset että geneettiset todisteet tukivat teoriaa, jonka mukaan Sundarbansin tiikereillä olisi ollut yhteyksiä mannermaan tiikereihin aivan viime aikoihin asti. Geneettinen isolaatio mannermaan tiikereistä ja adaptaatio mangrove-ekosysteemiin ovat yhdessä muovanneet Sundarbansin tiikereiden geneettistä arkkitehtuuria. Tämän vuoksi Sundarbansin tiikerit vaativat erityistä suojelua, jotta niiden geneettinen ainutlaatuisuus ja kyky sopeutua erityisolosuhteisiin säilyisivät myös tulevaisuudessa. Populaatiota täytyy hoitaa evolutiivisesti merkittävänä yksikkönä (evolutionary significant unit; ESU) adaptiivisen evolutiivisen suojelun (adaptive evolutionary conservation; AEC) kriteeristön mukaisesti. Tutkimuksessa kiinnitettiin huomiota myös ongelmiin, joita saattoi ilmetä aikaisemmin ehdotetuissa menetelmissä eri sukupuolten kautta kulkevan geenivirran määrän arvioimiseksi ja ehdotettiin vaihtoehtoista menetelmää tarkempien arvioiden saamiseksi.

Many sharks have life history characteristics (e.g., slow growth, late age at maturity, low fecundity, and long gestation periods) that make their populations vulnerable to collapse due to overfishing. The porbeagle (Lamna nasus), bull shark (Carcharhinus leucas), great hammerhead (Sphyrna mokarran), and smooth hammerhead (S. zygaena), are all commercially exploited. The population genetic structure of these species was assessed based on globally distributed sample sets using mitochondrial control region (mtCR) sequences and/or nuclear markers. Complex patterns of evolutionary and demographic history were inferred using coalescent and statistical moment-based methods. All four species showed statistically significant genetic partitioning on large scales, i.e., between hemispheres (L. nasus mtCR φST = 0.8273) or oceanic basins (C. leucas nuclear FST = 0.1564; S. mokarran mtCR φST = 0.8745, nuclear FST = 0.1113; S. zygaena mtCR φST = 0.8159, nuclear FST = 0.0495). Furthermore, S. zygaena mtCR sequences indicated statistically significant matrilineal genetic structuring within oceanic basins, but no intrabasin structure was detected with nuclear microsatellites. S. mokarran showed statistically significant genetic structure between oceanic basins with both nuclear and mitochondrial data, albeit with some differences between the two marker types in fine scale patterns involving northern Indian Ocean samples. A microsatellite assessment of C. leucas demonstrated no population structuring within the Atlantic or Indo-Pacific, with the exception that samples from Fiji were differentiated from the remaining Indo- Pacific Ocean locations. In contrast, the L. nasus mitochondrial and nuclear ITS2 sequences revealed strong northern vs. southern hemispheric population differentiation, but no differentiation within these hemispheres. These geographic patterns of genetic structure were used to determine the source of fins obtained from the international fin trade and to develop forensic tools for conservation.