Biology subjects

Kojola, I.

Publications and source records attributed to Kojola, I..

4 recordsLinked to original sources

bioRxiv2026

The population structure and genetic health of European wolves

Once nearly eradicated from Europe, grey wolves (Canis lupus) have recently undergone a remarkable demographic recovery, but their long-term survival remains precarious. By analyzing 1,001 genomes, we uncover a mosaic of distinct evolutionary lineages, not a single recovering population. Northern populations exhibit Asian wolf ancestry, while southern populations preserve ancient Holocene lineages, with dog introgression varying by region. Isolated wolves from the Scandinavian, Italian, and Iberian peninsulas harbored particularly high levels of inbreeding and fixed deleterious mutations. Signatures of genome erosion were widespread across Europe, with many populations falling well short of the minimum size recommended for long-term survival. Our study reveals the complex tapestry of wolf ancestry and variation across Europe, which calls for nuanced, regional conservation plans founded in genetic monitoring.

genomics↗

bioRxiv2024

Human footprint and forest disturbance reduce space use of brown bears across Europe.

Three-quarters of the planets land surface has been altered by humans, with consequences for animal ecology, movements and related ecosystem functioning. Species often occupy wide geographical ranges with contrasting human disturbance and environmental conditions, yet, limited data availability across species ranges has constrained our understanding of how human impact and resource availability jointly shape intraspecific variation of animal space use. Leveraging a unique dataset of 752 annual GPS movement trajectories from 370 brown bears (Ursus arctos) across the species range in Europe, we investigated the effects of human impact (i.e., human footprint index), resource availability, forest cover and disturbance, and area-based conservation measures on brown bear space use. We quantified space use at different spatio-temporal scales during the growing season (May - September): home range size; representing general space requirements, 10-day long-distance displacement distances, and routine 1-day displacement distances. We found large intraspecific variation in brown bear space use across all scales, which was profoundly affected by human footprint index, vegetation productivity, and recent forest disturbances creating opportunity for resource pulses. Bears occupied smaller home ranges and moved less in more anthropized landscapes and in areas of higher resource availability. Forest disturbances reduced space use while contiguous forest cover promoted longer daily movements. The amount of strictly protected and roadless areas within bear home ranges were too small to affect space use. Anthropized landscapes may hinder the expansion of small and isolated populations, such as the Apennine and Pyrenean, and obstruct population connectivity, for example between the Alpine or Carpathian with the Dinaric Pindos populations. Our findings call for actions to maintain bear movements across landscapes with high human footprint, for example by maintaining forest integrity, to support viable bear populations and their ecosystem functions.

ecology↗

bioRxiv2022

Genomes of the extinct Sicilian wolf reveal a complex history of isolation and admixture with ancient dogs

The Sicilian wolf represented the only population of wolves living on a Mediterranean island until the first half of the twentieth century (1930s-1960s) 1-7. Previous studies hypothesised that they remained isolated from mainland wolves from the end of the Last Glacial Maximum (LGM) 8,9, until human persecutions led them to extinction 1-7. There are only seven known Sicilian wolf specimens from the 19th and 20th century preserved in museums in Italy and recent morphometric analyses assigned them to the new subspecies Canis lupus cristaldii 10. To better understand the origins of the Sicilian wolf, and its relationship to other wolf populations, we sequenced four whole genomes (3.8x-11.6x) and five mitogenomes. We investigated the relationship between Sicilian wolves and other modern breeds to identify potential admixture. Furthermore, considering that the last land-bridge between Sicily and Italy disappeared after the LGM 11, around 17 kya, we explored the possibility that the Sicilian wolf retained ancestry from ancient wolf and dog lineages. Additionally, we explored whether the long-term isolation might have affected the genomic diversity, inbreeding levels and genetic load of the Sicilian wolf. Our findings show that the Sicilian wolves shared most ancestry with the modern Italian wolf population but are better modelled as admixed with European dog breeds, and shared traces of Eneolithic and Bronze age European dogs. We also find signatures of severe inbreeding and low genomic diversity at population and individual levels due to long-term isolation and drift, suggesting also low effective population size.

genomics↗

bioRxiv2021

Assessment of the Finnish wolf population combines DNA captures, citizen observations and mortality data using a Bayesian state-space model

Assessment of the Finnish wolf population relies on multiple sources of information. This paper describes how Bayesian inference is used to pool the information contained in different data sets (point observations, non-invasive genetics, known mortalities) for the estimation of the number of territories occupied by family packs and pairs. The output of the assessment model is a joint probability distribution, which describes current knowledge about the number of wolves within each territory. The joint distribution can be used to derive probability distributions for the total number of wolves in all territories and for the pack status within each territory. Most of the data set comprises of both voluntary-provided point observations and DNA samples provided by volunteers and research personnel. The new method reduces the role of expert judgement in the assessment process, providing increased transparency and repeatability.

ecology↗