Genetic heterogeneity is considered an important parameter for individual fitness and reproductive success. In 1999 and 2000, we studied the population genetics of great tit (Parus major L., 1758) in southwestern Germany from two different forest types (deciduous and mixed-coniferous), which may significantly differ in prey diversity and/or food supply. Adults of 99 families were genotyped at four enzyme and eight microsatellite loci, in order to estimate individual heterozygosity. In the mixed-coniferous forest, a significant positive correlation between the genetic heterogeneity of females and early egg-laying date and clutch size was detected. Early egg-laying date and increased clutch size are conditions that positively affect the number of fledglings. This effect of individual heterozygosity was not observed in the deciduous woodland. Maternal genetic heterogeneity, however, did not correlate with fledgling condition, and individual heterozygosity of fathers had no impact on breeding success in either habitat. The positive effect of female genetic heterogeneity on brood size of great tits in mixed-coniferous forests is attributed to early egg-laying date, i.e. a maternal effect, rather than to a specific mating strategy that optimizes fitness through an increased brood size and the quality of offspring. Individuelle Fitness und reproduktiver Erfolg werden oftmals in einem engen Zusammenhang mit genetischer Heterogenität gesehen. In den Jahren 1999 and 2000 untersuchten wir Kohlmeisenpopulationen (Parus major L., 1758) in süddeutschen Laub- und Nadelmischwäldern. Beide Waldformen können sich bzgl. der Futterdiversität und Futterverfügbarkeit stark unterscheiden. Die Alttiere von 99 Familien wurden für vier Enzym- und acht Mikrosatellitenloci genotypisiert, um die individuelle Heterozygotie abzuschätzen. Im Nadelmischwald fand sich eine signifikante positive Korrelation zwischen der individuellen Heterozygotie der Weibchen und Legedatum sowie Gelegegröße. Ein frühes Legedatum und ein größeres Gelege haben einen positiven Effekt auf die Anzahl von Jungtieren. Ein solcher Effekt konnte im Laubwald allerdings nicht beobachtet werden. Weiterhin bestand kein Zusammenhang zwischen maternaler genetischen Heterogenität und der Masse der Jungtiere, ebenso hatte die väterliche genetische Heterogenität in beiden Waldformen keinen signifikanten Einfluß auf den Bruterfolg. Der positive Effekt mütterlicher genetischer Heterogenität auf die Zahl der Nachkommen von Kohlmeisen im Nadelmischwald steht in engem Zusammenhang mit dem Legedatum, d.h. ein maternaler Effekt erklärt eher die beobachteten Zusammenhänge als eine spezifische Paarungsstrategie, die sich entwickelte und zur Fitnessoptimierung führte. Table S2. The pairwise correlation analysis betwen brood parameters (egg-laying date, clutch size, hatching date, number of hatchlings, number of fledglings, total brood mass and mean body mass of fledglings are given Table S3. Pearson's correlation coefficients of female genetic heterogenicity and three standardized brood parameters (egg-laying date, clutch size and fledgling success) of great tits in the mixed-coniferous and deciduous forests are listed Please note: Blackwell Publishing are not responsible for the content or functionality of any supplementary materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
The enormous destruction of natural habitats in Madagascar by humans forces us to initiate programmes for the conservation of its endangered species, such as the lemurs. At present, our knowledge of the population biology of these species is rather limited and this study has, therefore, been undertaken to learn more about the genetics of lemurs. In the past, conservation biology has been influenced mainly by ecology, but the necessity of genetic approaches has been widely recognized during the last 15 years [1–5]. The structure of natural populations, e.g. the amount of genetic variability, the degree of genetic diversity among local populations and, of course, correlations between local environmental conditions and genetic variability should be known in order to optimize in situ and ex situ conservation programmes. Genetic studies can help to minimize the increase in inbreeding within breeding groups [6] and to preserve the genetic variability found in local natural populations [6, 7]. Of course, these ideas are only important if ex situ conservation is intended to be the basis of in situ programmes. If ex situ conservation is restricted to the breeding of species within zoological gardens in order to illustrate the problem of endangered species to the public, a mixture of populations adapted to different environmental conditions bears no risk, as long as the captive-bred individuals are kept in human care. If ex situ conservation programmes aim to release individuals into natural habitats, maladaptation of hybrid individuals can occur under natural conditions.
Prologue.- Inactivation of gene expression in transgenic plants.- The impact of transposable elements on genome evolution in animals and plants.- Evolutionary changes of the structure of mobile genetic elements in Drosophila.- Mechanisms and consequences of horizontal gene transfer in natural bacterial populations.- Evolutionary genetic considerations on the goals and risks in releasing transgenic crops.- Transmission of insect transposons into baculovirus genomes: An unusual host-pathogen interaction.- Influence of transgenes on coevolutionary processes.- The two strategies of biological containment of genetically engineered bacteria.- Monitoring genetically modified organisms and their recombinant DNA in soil environments.- Recent advances in ecological biosafety research on the risks of transgenic plants: A trans-continental perspective.- Modern versus classical plant breeding methods - efficient synergism or competitive antagonism?.- Genetically modified food and its safety assessment.- Genetic intervention in human beings.- History of and progress in risk assessment.- Transgenic organisms and evolution: Ethical implications.- Genetic engineering and the press - Public opinion versus published opinion.- Epilogue.
