Thesis defence in the University of Oulu

Doctoral Candidate

Master of Science Johanna Honka

Faculty and research unit

University of Oulu Graduate School, Faculty of Science, Ecology and Genetics Research Unit

Field of study

Biology

Date and time of the thesis defence

15.5.2020 14:00

Place of the thesis defence

Remote connection, Zoom link: https://oulu.zoom.us/j/62513011932

Topic of the dissertation

Evolutionary and conservation genetics of European domestic and wild geese

Opponent

Doctor Robert Kraus, University of Konstanz

Custos

Professor Jouni Aspi, University of Oulu

Genetic methods aid in the conservation of taiga bean goose and revealing the history of domestic goose

In this doctoral thesis, two goose species utilized by humans were studied. The first one was the bean goose, of which the declining taiga bean goose subspecies was found to form only one genetic population within Finland, whereas the non-endangered tundra bean goose was found mainly as a migrant passing south-eastern Finland. By restricting bean goose hunting to south-eastern Finland, taiga bean goose can be protected from excessive harvesting. The second study species, the domestic goose was in focus to examine the evolutionary history of Russian domestic geese from the Middle Ages to the Modern period. The domestic goose was studied by analysing DNA extracted from archaeological domestic goose samples.

The taiga bean goose has been hunted despite of decline in population numbers and thus requires conservation. In this study, the taiga bean goose individuals and their kinships were identified based on DNA extracted from field collected feathers. All the taiga bean geese breeding in Finland were found to belong to the same population. In addition, about 4% of these geese had inherited DNA from pink-footed goose, which indicates hybridization between these species.

Using genetic subspecies identification, an area was identified in south-eastern Finland in which over ten times more prevalent tundra bean goose subspecies occurs during the hunting season. This information is utilized in the management of the taiga bean goose by restricting the bean goose hunting area to this specific region in order to spare the taiga bean goose from hunting. Identification of the different subspecies of the bean goose is challenging based on their appearance alone and thus subspecies have not been previously defined in the hunting bag statistics. Here, genetic methods were used to obtain reliable subspecies identification.

The domestic goose is a common and a widespread poultry species. It has descended from the greylag goose but otherwise its domestication history still remains unknown. In this study three genetic groups were identified within the archaeological domestic goose bones excavated from Russia (3rd to 17th century AD): domestic geese, eastern domestic or greylag geese and taiga bean geese. Undoubted domestic geese were present from the 11th century onwards. The finding of taiga bean goose bones was surprising but probably explained by the fact that the archaeological bones are often fragmented, which makes the species identification difficult.

 

Dissertation

Last updated: 5.5.2020