Sökning: "small population size"
Visar resultat 6 - 10 av 220 avhandlingar innehållade orden small population size.
6. Genomic analysis of the process leading up to the extinction of the woolly mammoth
Sammanfattning : Species worldwide are subject to contractions in both abundance and geographical range, and their persistence in a changing environment may thus depend on the ability to survive in small and fragmented populations. Despite the urgent need to understand how extinction works, our knowledge of pre-extinction genetic processes is limited because techniques allowing population and conservation genomics to be studied in wild threatened populations have become available only recently. LÄS MER
7. Population size and genetic diversity of Nigerian lions (Panthera leo)
Sammanfattning : High growth rate in human populations, agricultural developments and industrialization have impinged negatively on the natural habitats of most large carnivores, causing fragmentation, isolation and consequently reduction in population size. Lions (Panthera leo) that once roamed most parts of Southern Europe, Asia, the Middle East, North America, northern part of South America and most parts of Africa are today found only in parts of sub-Saharan Africa and at a single site in India. LÄS MER
8. Spatial and temporal population dynamics in the mountain tundra – mesopredator and prey
Sammanfattning : It is well known that competition, predation and fluctuating food resources can have strong effect on individual fitness and population dynamics. The complexity of natural systems can make it complicate to disentangle those processes, but environments with relatively simple food webs, and strong cyclic population dynamics offer contrasting conditions resembling experimental treatments. LÄS MER
9. Genetic variation and population differentiation in the forest herb Lathyrus vernus (Fabaceae)
Sammanfattning : In the present thesis, I investigated patterns of genetic variation in the forest herb Lathyrus vernus (Fabaceae), using plant material from different-sized populations representing three geographically separated regions: central Europe, southern and central Sweden. My studies included presumably neutral or weakly selected characters (allozymes and leaflet shape) as well as characters that should be under strong directional selection (e. LÄS MER
10. Ecology and genetic population structure of Indo-Pacific bottlenose dolphins in East Africa
Sammanfattning : Many marine mammal populations are threatened by anthropogenic activities. The Indo-Pacific bottlenose dolphins (Tursiops aduncus) off Zanzibar are subject to high levels of bycatch, negative impact from tourism and were previously hunted. LÄS MER