Klaipėdos universitetas

The article describes the possibilities and limitations of ancient DNA research on organic materials that are usually not the focus of archaeogenetics, because of their low preservation potential and thus rareness in archaeological settings. These are remains from fish and birds, animal hairs, and coprolites. Several of the author’s own key studies from different regions and time periods are presented.

The Neolithic site of Priedaine in Jūrmala was excavated on a small scale in 2007–2008, yielding an assemblage of Comb Ceramics, along with unique wooden implements and fragments of pine-lath fishing structures. The environment and subsistence resources are indicated by plant macrofossil remains and a small faunal collection. Located by a palaeolake and also very close to the sea, the site, dated to c. 3700–3500 cal BC, would have been oriented towards aquatic resource exploitation. However, it had a wider range of functions, as indicated by the evidence of flint and amber processing.

The paper presents the results on the dimensionality reduction technique which is based on radial basis function (RBF) theory. The technique uses RBF for mapping multidimensional data points into a low-dimensional space by interpolating the previously calculated position of so-called control points. This paper analyses various ways of selection of control points (regularized orthogonal least squares method, random and stratified selections). The experiments have been carried out with 8 real and artificial data sets. Positions of the control points in a low-dimensional space are found by principal component analysis. Combinations of RBF technique with random and stratified selections outperformed RBF with regularized orthogonal least squares algorithm regarding to computation time analysing all data sets. We demonstrate that random and stratified selections of control points are efficient and acceptable in terms of balance between projection error (stress) and time-consumption.