A total of 193 brown hares, collected from 7 sampling sites in Poland during 1986 - 1990 were examined for genetic variability and differentiation at 39 presumptive isozyme loci by means of horizontal starch gel electrophoresis. Values of polymorphism (mean P = 0.180, SD 0.039) and average heterozygosity (mean H = 0.047, SD 0.006) were similar to those detected in previous studies on the population genetics of the brown hare. Relative (Cst = 0.041) and absolute (mean D/Nei, 1978/ = 0.0012, SD 0.0013) genetic differentiation among populations were very low, which fits well to the high number of migrant individuals per generation (Nm = 12.7), estimated using the private allele method of Slalkin (1985). Average heterozygosity was examined for associations with geographical distribution, the year of culling, population density, age, sex, body weight and health status, whereby a better survival of heterozygous femals could be detected. According Lo our results, the present decline of the brown hare is noL due to genetic depiction. However, once population sizes drop below a critical threshold, a pronounced inbreeding depression can be expected.
One of the dramatic effects of global warming is the retreat of glaciers. This phenomenon has intensified in the last two decades. Postglacial areas are quickly colonised by various groups of organisms. Auto- and heterotrophic microorganisms play an especially vital role in these processes. They thrive in shallow glacial lagoons which often form in front of retreating glaciers. These reservoirs are characterised by high dynamics of physicochemical parameters, including: salinity, temperature and concentrations of organic compounds and nutrients. The conducted microbiological studies have revealed rich structural and functional diversity of bacteria occurring in the ecosystem of Ecology Lagoon situated on King George Island. Bacteria found on the surface of algae and stones in the shore zone of the lagoon showed particularly intense metabolic activity. A molecular analysis has indicated that unique taxonomic groups of bacteria occur in the ecosystem of Ecology Lagoon.