Aarhus Universitets segl

Publikationer og Aktiviteter

Publikationer

- Ortego et al (2024) Semi-natural areas act as reservoirs of genetic diversity for crop pollinators and

         natural enemies across Europe. Conserv Sci Pract 

- Johnson et al (2023) The meso scale as a frontier in interdisciplinary modeling of sustainability from

         local to global scales. Environ. Res. Lett. 18, 025007. https://doi.org/10.1088/1748-9326/acb503

Alexander, P. et al. (2022) High energy and fertilizer prices are more damaging than food export

         curtailment from Ukraine and Russia for food prices, health and the environment. 

         Nat Food. https://doi.org/10.1038/s43016-022-00659-9

Konferencebidrag

- Videnskabelige foredrag

- Population Genetics Group56, UK 2023

Does genetic diversity predict fitness in wild arthropod populations?  Tammy A.T. Ho, Trine Bilde, Tove Hedegaard Jørgensen

A positive relationship between genetic diversity and population fitness is a fundamental expectation of population genetic theory. We have evidence for this in laboratory or captive populations; however, when population genetic diversity is estimated in a laboratory setting, effective population size is typically reduced artificially by using inbred lines. This makes it difficult to disentangle the effects of inbreeding from diversity in standing genetic variation at population level. Studies on genetic diversity in natural populations show ambiguous effect on population performance, and data from some taxonomic groups are scare. Here I performed a systematic review on the relationship between genetic diversity and performance in natural populations of arthropods. The majority studies were on immunity and reproductive performance, mostly demonstrating a positive correlation between genetic diversity and performance. For other performance traits, the data was scanty with mixed results. A strong taxonomic bias was detected with most studies performed on social hymenopteran species. Furthermore, most studies used relatively few microsatellite markers, which may not accurately capture genome-wide genetic diversity. This work reveals important gaps in the field, including the need for studies that include estimates from a higher number of populations, from a wider range of arthropod taxa and performance traits, and using whole-genome methods to obtain more markers to robustly detect relationships between genetic diversity and population performance. 

 

- 11th International Workshop on Molecular Biology and Genetics of the Lepidoptera, Greece, 2022. (Invited keynote)

Adding genomic data on an ecological model system, the Glanville fritillary butterfly. - Bras A., Saastomoinen M.

 

- European Society for Evolutionary Biology, Prague, Czech Republic, August 2022 (invited speaker)

Performance, plasticity, and adaptive potential across environmental gradients - Verspagen, N., Halali, S., DiLeo, M., Saastamoinen, M.

Environmental conditions in nature are highly variable in space and time, yet organisms must adapt to them in order to succeed. On-going climate change poses further challenges for adaptation as both the means and the variability of environmental conditions are shifting. It is becoming increasingly evident that successful adaptations often require both local adaptation and adaptive plastic responses, latter which may also include transgenerational effects. I will present some on-going work in the classic model in eco-evolutionary dynamics, the Glanville fritillary butterfly, where we address the role of local adaptation and plastic responses in relation to climate change adaptation. We combine experimental manipulations with genomic analyses using individuals originating from natural populations across environmental gradients. Generally we find evidence for local adaptation as well as strong within-generation plasticity for temperature. Individuals from populations across the environmental gradient vary in plasticity with the Northern populations showing both higher plasticity as well as higher intra-population variation for plasticity. Evidence for adaptive transgenerational plasticity in this population is, on the other hand, generally weak, presumably due to low predictability of temperature fluctuations within the growing season. Whole genome sequence data revealed evidence for local adaptation to climate but only few candidate loci overlapped between two altitudinal gradients, in the Alps and Pyrenes, suggesting divergent adaptive responses.

- Society for Experimental Biology, Montpellier, France, July 2022 (invited speaker)

Carry-over effects of environmental stress on butterfly performance - Saastamoinen, M.

 It is well-known that the environment experienced early in life often affects trait expression later on in individual’s life, with impacts evident even across generations. Such ‘carry-over effects’ and their fitness outcomes can be either positive (adaptive) or negative, and highly stress- or environment-dependent. I am using butterflies as a model system to address the  impact of carry over effects, as butterflies have distinct life stages and are highly responsive to environmental variation due to often being strictly adapted to specific resources and climatic microhabitats during their development. I will provide an overview of results from a set of experiments in which we have assessed the impact of carry over effects in response to different types of ecologically relevant stressors, namely malnutrition and thermal condition, experienced during development. The focus will be on developmental carry over effects on adult performance traits, such as lifespan, fecundity and dispersal propensity but I will also discuss some results related to trans-generation effects. The experiments have been carried out by comparing individuals from different families within a larger metapopulation or by comparing individuals from populations across a larger scale environmental gradient, shedding some light also on heritable variation in carry-over effects.

- Student symposium – University of Stockholm, Sweden, November 2022 (invited speaker)

Responses to Environmental Change in Butterflies - Saastomoinen M.

Invited talks

- University of Aberdeen, UK, March 2022 and University of Oulu, Finland, November 2022

Impact of human-induced environmental change on natural populations: butterflies as a model system. - Saastomoinen M.

- University of Reading, UK, January 2022

Coping with human-induced environmental change: butterflies as model system. - Saastomoinen M.

- University of Stockholm, Sweden, June 2022

Butterflies as a models system to understand how natural populations/ communities respond to anthropogenic change. - Saastomoinen M.

- Poster presentations

- Poster presentation - OIKOS - Finland 2023

Effects of Habitat Fragmentation per se on the Genetic Diversity of the Glanville Fritillary Butterfly - Multigner L. F., DiLeo M., Bras A., Saastamoinen M.

Habitat loss and fragmentation are considered the key drivers of biodiversity loss. While evidence indicates that habitat loss has a negative impact on biodiversity, there is no consensus on whether the effect of fragmentation per se – more discontinuous habitat distribution but no difference in habitat amount - is negative or positive. We studied how fragmentation per se affects genetic diversity (GD) while controlling for habitat amount in the Glanville fritillary butterfly metapopulation in the Åland islands. We used 40 SNP neutral markers from two years to calculate GD indices in over 200 habitat patches with relatively high population abundance. We estimated our appropriate landscape size to be a 3.5 km radius around each focal patch. We then selected patches with surrounding landscapes with a similar habitat amount but various number of patches, and assessed their respective effect on focal patch GD. Our first results support the habitat amount hypothesis, as the number of fragments had a neutral effect on the GD. However, further assessment of lack of contrast or statistical power in our dataset is required as we also failed to find a significant effect of the habitat amount.

- Poster presentation - OIKOS - Finland 2023

Unraveling the link between population fluctuations with changes in genetic diversity in Finnish butterflies - Bras A, Kaila L, Jensen M R, Djernæs M, Bechsgaard J, Bilde T, Francis Thomsen P, Saastamoinen M

Insects have been reported declining worldwide in terms of numbers of species but also in population densities. Several factors such as climate change, pollution or land-use changes have been pointed out as main drivers of these declines. Whereas species losses are quantifiable through long term biodiversity monitoring, genetic losses remain difficult to quantify over time. The long-term monitoring surveys of butterflies in Finland have shown that they respond differently to climate change with species presenting various population trends. This baseline offers the opportunity to assess how factors responsible for insect decline has shaped genetic diversity over time. Using a museomics approach, we aim to (i) investigate the changes in genetic diversity during the last century for butterfly species showing population decline, and (ii) to assess how genetic diversity has changed for species belonging to the same genus but presenting contrasting population trends. To study this, we will sequence whole genomes of museum specimens collected at historical time points and compare the data with contemporary samples from same areas of each species of interest to look for genetic patterns.
 

- Poster presentation - Ecological Immunity Workshop, Germany, 2023

Effective population size, genetic diversity and immune function in a soil arthropod. Tammy A.T. Ho, Jørgen A. Axelsen, Jesper S. Bechsgaard, Tove H. Jørgensen, Trine Bilde

The ability of populations to maintain an effective immunity against diseases and parasites relies on the presence of genetic diversity. Genetic diversity protects against widespread infection in the population if the disease shows genetic specificity for infection. Therefore, genetically diverse host populations face a lower risk of infections. Genetic diversity can be reduced when there is a population decline which subsequently may affect the population immunity. Collembolas are soil microarthropods and are constantly exposed to potentially infectious fungi and bacteria, hence it is important for collembola populations to maintain effective immunity to survive. With agricultural practices intensifying, this causes high mortality in many collembola populations in the agricultural fields. Due to the high importance of collembola to soil processes, it is critical that we understand how a reduction in their genetic diversity can affect their immunity and subsequent survival. In my poster, I will be presenting my PhD research plans on measuring natural varying genetic diversity through population genetics, measuring immunity gene variation to assess whether there is selection to maintain effective immunity in small populations, and culturing collembola from the respective populations for immune assays to associate genetic diversity and immunity performance.

 

Poster presentation - OIKOS - Finland 2023

Unraveling the link between population fluctuations with changes in genetic diversity in Finnish butterflies - Bras A, Kaila L, Jensen M R, Djernæs M, Bechsgaard J, Bilde T, Francis Thomsen P, Saastamoinen M

Insects have been reported declining worldwide in terms of numbers of species but also in population densities. Several factors such as climate change, pollution or land-use changes have been pointed out as main drivers of these declines. Whereas species losses are quantifiable through long term biodiversity monitoring, genetic losses remain difficult to quantify over time. The long-term monitoring surveys of butterflies in Finland have shown that they respond differently to climate change with species presenting various population trends. This baseline offers the opportunity to assess how factors responsible for insect decline has shaped genetic diversity over time. Using a museomics approach, we aim to (i) investigate the changes in genetic diversity during the last century for butterfly species showing population decline, and (ii) to assess how genetic diversity has changed for species belonging to the same genus but presenting contrasting population trends. To study this, we will sequence whole genomes of museum specimens collected at historical time points and compare the data with contemporary samples from same areas of each species of interest to look for genetic patterns.