This thesis was focused on suitability of selected molecular markers for detection of genetic variability of four species from the family Calliphoridae important in the forensic entomology. A set of eight markers, both mitochondrial (COI, ND6, CytB, CR) and nuclear (RP S12, RP S13, RP L12, PB2), were applied on samples from natural populations of representative species (Calliphora vicina, Lucilia caesar, Lucilia sericata, Phormia regina) most common in the Czech Republic. Level of detected variability was evaluated and compared, both with respect to the particular species as well as their geographic origin.

Isopods in the genus Tylos are distributed in tropical and subtropical sandy intertidal beaches throughout the world. These isopods have biological characteristics that are expected to severely restrict their long-distance dispersal potential: (1) they are direct developers (i.e., as all peracarids, they lack a planktonic stage); (2) they cannot survive in the sea for long periods of immersion (i.e., only a few hours); (3) they actively avoid entering the water; and (4) they are restricted to the sandy intertidal portion that is wet, but not covered by water. Because of these traits, high levels of genetic differentiation are anticipated among allopatric populations of Tylos. We studied the phylogeographic patterns of Tylos in the northern East Pacific region between southern California and central Mexico, including the Gulf of California. We discovered high levels of cryptic biodiversity for this isopod, consistent with expectations from its biology. We interpreted the phylogeographic patterns of Tylos in relation to past geological events in the region, and compared them with those of Ligia, a co-distributed non-vagile coastal isopod. Furthermore, we assessed the usefulness of the shape of the ventral plates of the fifth pleonite for distinguishing genetically divergent lineages of Tylos in the study area. Finally, mitochondrial phylogenenetic analyses to identify the most appropriate outgroup taxa for Tylos in the study area, which included 17 of the 21 currently recognized species, provided important insights on the evolutionary history of this genus.