Genetics of animal populations in urban environments

Laylo Zokirova

Bachelor's thesis

Abstract:

Species inhabiting urban and near-urban habitats be negatively affected when urbanization and associated environmental changes inflict population isolation, reduced gene flow, local diversity declines, and genetic drift. Declines are partly due to species inhabiting disturbed or fragmented habitats, or their proximity. This a cause for concern because gradually, genetic issues can lead to local extinction. Loss of biodiversity caused by habitat loss and fragmentation may be underappreciated consequence of city expansions. However, it is not yet well understood if occurring changes threaten species generally across taxa. I investigated this question by reviewing a number of studies that either focused on individual species or conducted secondary data analyses. For each species, I estimated the effects of urbanization on genetic diversity and genetic structure as measures of urbanization. Data was collected from scientific journals and articles, and an overview is presented in a table, in a form of direct comparison of species from various taxa. Analysis of research revealed that study results and urbanization effects are not generally applicable across taxa, but should be addressed on a case-by-case basis. Results suggest that, in general, less mobile species living in or in proximity to fragmented or disturbed habitats are more susceptible to environmental changes, and are more likely to suffer from restricted gene flow. The majority (75%) of studied species are affected by urbanization negatively, their genetic diversity and structure, regardless of their class, were affected by urbanization: 53% and 71% respectively. Species’ genetic diversity and structure did not respond to urbanization in 41% and 23% of the studies, respectively. 6% responded to urbanization positively. 7,5% of reviewed studies tested species for the development of adaptive genes. In those studied it was discovered that in 80% of cases studied organisms, despite belonging to different classes (mammals and insects), have developed adaptive SNPs.

Keywords

city genetics, urban environment, habitat fragmentation, genetic diversity and structure, genetic drift

Language used: English

Date on which the thesis was submitted / produced: 22. 3. 2023

Thesis defence

• Date of defence: 25. 5. 2023
• Supervisor: Ing. Jana Svobodová, Ph.D.
• Reader: Silvie Neradilová, Ing.

Czech University of Life Sciences Prague

Faculty of Environmental Sciences

Bachelor programme:
Applied Ecology