|
|
Causes of bee loss (Anthophila) in the landscape
Bureš, Vít ; Straka, Jakub (advisor) ; Tropek, Robert (referee)
Bees (Anthophila) are one of the most important pollinators in the majority of Earth's biotopes. They interact with almost one-fifth of flowering plants and together with other pollinators they secure one- third of human food sources. Since the end of World war II,along-term decrease in numbers of bees and other insects is observed due to degradation of natural habitats, expansion of agriculture, pesticide usage, parasites, and infections. In North America and Europe, several studies reported a significant loss of bee diversity and abundance. The situation in tropics is unclear and there is not enough evidence if bees are threatened there. Specific changes in relation to the decrease of the bee population are observed in the case of honey bee (Apis mellifera). Due to human beekeeping activities and specific honey bee attributes such as bigger body size or tolerance to lower temperature, honey bees show different trends in their abundance than other bees. This study discusses the causes of these losses and possible future consequences, for example, the collapse of ecosystems as a result of pollination crisis or lack of human food. On the other hand, several phenomena such as extensive agriculture, green cities, or wildfires have a positive impact on bee abundance and diversity. This thesis presents...
|
|
|
Parental care and sociality in family Halictidae (Anthophila)
Vinická, Eliška ; Straka, Jakub (advisor) ; Klimeš, Petr (referee)
Halictidae is an important family of bees interesting mainly for the diversification of social organisation of individual species. Their sociality ranges from solitary individuals who live and care for their offspring themselves, through species that build common nests, to eusocial colonies in which the reproductive division of labour has developed. Exploring such diversity among closely related species may contribute to understanding the evolution of sociality. Thus, we can observe the development of social organization up to its higher levels, such as eusociality, or conversely, gradual evolutionary regression to solitary individuals. For such research, however, it is necessary to know not only the phylogenetic development but especially a detailed description of social behaviour in individual species. However, there are few such studies. Some of them are summarized in this work.
|
|
|
Genome Assembly and Annotation of Biparental Bee Ceratina nigrolabiata
Fraňková, Tereza ; Straka, Jakub (advisor) ; Kolísko, Martin (referee)
Biparental care in Hymenoptera is a little studied behaviour. This kind of parental care was discovered and the ethological aspect described in the bee Ceratina nigrolabiata from the Czech Republic and is well understood on the ethological level. However, biparental care is not a common behaviour and the lack of genomic studies of this behaviour complicates the understanding of the origin of the biparental care and its underlying pathways on the genomic and physiological level. This master's thesis presents the genome analyses of a biparental bee Ceratina nigrolabiata. It consists of a brief summary of the known parental behaviour across insects, characteristics of the genus Ceratina, summary of the used genomic methods and presents a candidate genes for the transcriptomic study of the biparental behaviour of Ceratina nigrolabiata. Key words: biparental care, genomics, Hymenoptera, Insecta, Ceratina, small carpenter bees
|
|
|
Evolution of sociality and parental care in bees of the genus Ceratina
Mikát, Michael ; Straka, Jakub (advisor) ; Schwarz, Michael (referee) ; Bogusch, Petr (referee)
Small carpenter bees (genus Ceratina) are an excellent model taxon for the study of evolution of parental care and origin of eusociality. Prolonged offspring care is typical for this bee genus. Females usually guard their offspring until adulthood and later feed their adult offspring pollen and nectar. Moreover, most of studied species are facultatively eusocial, a trait probably inherited from the common ancestor of the genus. Although Ceratina bees have generally very interesting behavior, detailed studies were performed in only a few species, usually from North America, Japan and Australia. Only anecdotal observations of natural history existed for a few European species, and detailed research has not been performed before my thesis. The goal of my thesis is to explore the natural history of European species of Ceratina and to identify possible costs and benefits of this species' behavioral traits. I focused on following these behavioral traits: social nesting, guarding of offspring until adulthood, and feeding of mature offspring. Through my master project, I discovered biparental care in species C. nigrolabiata, therefore the most important goal of my Ph.D. project is the evaluation of costs and benefits of this behavior. Guarding of offspring by mother significantly influences their survival,...
|
|
|
Population genetics of bees
Beranová, Tereza ; Straka, Jakub (advisor) ; Munclinger, Pavel (referee)
Bees are one of the most important group of all insect, which plays a significant role in crop pollination. This bachelor thesis is review of articles, which speaks about genetic diversity of Apidae (Apoidea, Anthophila) and factors, which influence genetic diversity of this family. This thesis represents anthhropogenic impact, such as urbanization and fragmentation, and impact, which was not caused by human population, such as, climate change and parasite impact, on bee population. Part of this thesis is created by bee life overview and basic information about population genetics. The aim of this work is finding extent of declining pollinator problem, especially wild bees and also naming the bacic methods, which are used in this work. Key words: population, DNA analysis, threats, conservation genetics, bees, biogeography
|
|
|
Comparative analysis of working age population mortality in selected developed countries
Straka, Jakub ; Burcin, Boris (advisor) ; Rybová, Kristýna (referee)
Comparative analysis of working age population mortality in selected developed countries Abstract The main aim of this thesis was to analyze trends in mortality situation of working-age population (20-64 years old) in 31 developed countries in period 1995-2010 and to find similarities and differences between them. Temporary life expectancy was used as an indicator which summarizes the intensity of mortality in productive age. One-dimensional and two-dimensional decomposition revealed the contributions of individual age groups and selected nine major groups causes of death defined by ICD to the difference in temporary life expectancy values between 1995 and 2010 in five selected countries. An analysis of the development of this indicator has shown that there has been a prolongation of life span in working age in all surveyed countries and differences in mortality rates between countries decreased. Major cause of this trend was probably reduction of the mortality rate in the middle-aged population, mainly of external causes, in the 20-54 age group in countries with lower life expectancy rates. However, to verify this hypothesis, it would be necessary to analyze other developed countries with a higher level of mortality in working age population than Bulgaria and Lithuania. Countries with higher temporary life...
|
|
|
Signs of the Origin and Evolution of Eusociality in Hymenoptera on Genomic Level
Fraňková, Tereza ; Straka, Jakub (advisor) ; Musilová, Zuzana (referee)
Eusociality has evolved independently many times in social Hymenoptera and some of them are now at the brink of eusociality. Eusociality is a complicated set of genomic, ecological and behavioural traits closely interacting with each other. Recent studies presented many interesting outcomes which explain at least partially the possible connections to eusociality on the genomic level. However, the true origin and evolution of eusociality is yet to be refined. Because eusociality is such a dominant quality in the lives of eusocial Hymenoptera, it is important to clarify what causes eusociality to arrise. This thesis summarises the most prominent findings in the field of genomics and reviews not only the outcomes but also the issues of this problematics. The thesis deals with the classification of eusociality, brief introduction to the species lifestyles, which are of great importance for understanding the main part. The main part focuses on the concrete genomic data elucidating possible signs of the evolution of eusociality recognised so far. Key words: eusociality, genomics, evolution, Hymenoptera, Insecta
|
|
|
Reintroduction of butterflies (Lepidoptera)
Štochlová, Tereza ; Sedláček, Ondřej (advisor) ; Straka, Jakub (referee)
The thesis deals with one of the active means of conservation - reintroduction. By this ap- proach, organisms are released in their historical range from which they have disappeared. Re- introductions typically concern vertebrates, that is, however, why this thesis focuses on a group of invertebrates - butterflies (Rhopalocera). The main aim of this work is to carry out a research of previous experiments, evaluate used methods and discover the best way to proceed with reintroduction of butterflies. This process contains many important steps. Firstly, a suitable species must be chosen, that means one that is declining and has limited dispersal abilities. Secondly, an appropriate habitat for releasing organisms must be found - host plants ought to be sufficiently abundant and the area big enough. If the habitat quality is not satisfactory, it can be achieved through management, most commonly by planting host plants, mowing or grazing. Next step is choosing the right donor population. It should be stable, genetically variable, and genetically and ecologically related to the original extinct population. After transfer and release of sufficient number of organisms, it is crucial to carry out a long-term monitoring of the newly formed population and to modify its management when necessary. All methods...
|
|
|
Population genetics and speciation in Stylops (Strepsiptera)
Kodejš, Karel ; Straka, Jakub (advisor) ; Černá, Kateřina (referee)
This thesis is focused to population genetics of selected species of genus Stylops in Europe. Within this genus, five species was analysed by usage of two approaches - microsatellite analysis in Stylops ater and analysis of mitochondrial DNA in all five species. Mitochondrial gene for cytochome c oxidase (1st subunit) was used. For microsatellite analysis was performed bayesian clustering analysis and ABC approach (Aproximate Bayesian Computation). Mitochondrial markers were processed by making haplotype networks and demography analysis by computing Bayesian skyline plots. For Stylops ater, surprisingly low lewel of population subdivision was detected, yet with clearly differentiated population clusters from Scandinavia and baltic coast of Europe, which may imply period of isolation of these populations or relativelly recent population expansion and genetic differentiation due to lower population sizes. Next, hypotesis of possible temporal segregation of subpopulations of Stylops nevinsoni based on different aktivity period of their host species groups, was supported. In other three species, population subdivision was observed to be related either due to host specialisation (Stylops mellitae) or geographic consequences (S.nassonowi, S.spreta). Interesting finding is also detection of population...
|
|
| |
guest ::
RSS feed.