Browsing by master's degree program "Ekologian ja evoluutiobiologian maisteriohjelma"

Post-transcriptional modifications (PTMs) in RNA are present in all known RNA species and conserved in all kingdoms of life. Transfer RNA (tRNA) has been shown to have numerous conserved modifications, which exemplifies the importance of modifications having impact on the structure of the tRNA and its function as carrier of the amino acids. Ribosomal RNAs (rRNA) are universally modified as well, and modifications are situated at functionally important spots of the ribosome. Given the fact that types and sites of modifications are conserved, it is likely that these modifications have been selected for and that they optimize the ribosomal structure and functions. Stress, such as temperature or infection by a pathogen, is known to change the presence or abundance of modifications in RNA molecules and thereby affect translation efficacy. In line with that, this master’s thesis project sought to gain insight into the dynamics of PTMs in tRNA and rRNA upon oxidative stress, with the goal of utilizing recently optimized UPLC/MS method for identifying modified ribonucleosides. As the specific aim of the thesis was to estimate the change in PTMs in tRNA and rRNA in response to oxidative stress with 0.5 mM and 2 mM hydrogen peroxide H2O2, 3 immediate goals were: (i) to isolate total tRNA from yeast grown in stress conditions, (ii) to isolate rRNA from yeast 80S ribosomes, and (iii) to identify present modifications using mass spectrometry. Yeast was cultured in presence of H2O2 as a stressor in mentioned concentrations, and both treatments considered showed a difference in survival when compared to the control. Rough cell concentration estimates (OD600) did not show the effect of the stressor on cell survival clearly, but when number of viable cells per mL was estimated, it was clear that growth of the stressed yeast cultures was hindered 2 hours after exposure to H2O2 but recovered during the 24 hours. Firstly, using UPLC/MS analysis, 29 modifications were identified in tRNA from control and H2O2 treated yeast. Most identified modifications showed no change in abundance in treatments, which is to be verified with additional replicates. However, distinct dynamics of stress-related change was found for several modifications, revealing additional modifications that may play a role in stress related modificome reprogramming to the previously known signature modifications of oxidative stress. It was expected that recovery of culture growth after 24 hours may be accompanied with modification level recovery. However, that was not demonstrated here as downregulation at 2 hours followed by upregulation at 24 hours was seen for 2-methylthio-N6-methyladenosine, N4-acetylcytidine and 5-methoxycarbonylmethyl-2-thiouridine, and the reverse was shown for N4-methylcytidine. Upregulation in both time points was also shown here for some modifications. Taken together, these results confirm a complex and dynamic control of tRNA modifications in cellular survival responses. Modifications found to be affected by oxidative stress are most frequently located on the wobble position 34 and anticodon loop position 37, so it is expected that changes in their modification levels could directly affect the tRNA function in translation, making them a specific target for future research. Secondly, modifications in rRNA from control yeast cultures were identified, such as expected methylations of all 4 canonical nucleosides. However, further analysis will be needed to confirm the other identified modifications, due to the potential mRNA and tRNA contamination. Optimizing the method for rRNA modifications identifications by acquiring more modified nucleosides specific for the rRNA to use as standards in the analysis, analyzing rRNA types separately and using tandem mass spectrometry would enable getting a deeper understanding of which modifications are present and where they are positioned. Finally, it would enable reliable identification of the signals of novel modifications present in rRNA, such as the tRNA modification 5-carbamoylmethyluridine signal found here. In conclusion, this thesis work lays the foundation to study the evolutionary conserved function of PTM changes during stress as modulators of translation, using the methodological approaches discussed in-depth within the thesis, primarily to confirm the intriguing results found here.

Biodiversity has been declining over the last decades due to land-use changes. Habitat loss and fragmentation are considered the key drivers of biodiversity loss. While evidence indicates that habitat loss has a negative impact on biodiversity, the effect of fragmentation itself is debated. The Habitat Amount Hypothesis proposes that fragmentation per se –more discontinuous habitat distribution but no difference in habitat amount- has no effect or even a positive effect on biodiversity. Studies have looked at its effect on species richness, but its impact on intraspecific genetic diversity is still unknown. In this thesis, I aimed to test this hypothesis using the Glanville fritillary butterfly, which has been extensively monitored in the Åland islands since 1990, as a model system. I studied how fragmentation per se affects genetic diversity of the focal populations, while controlling for the habitat amount within the landscape in the Åland islands. For this, I used an existing dataset for which larvae were sampled during two consecutive years and genotyped for 40 neutral SNPs, and calculated four genetic diversity indices in over 200 habitat patches with relatively high population abundance. Following Martin et al. (2021) protocol, I first defined the scale of effect. Then, to reduce the correlation between total habitat amount and number of habitat fragments, I split my dataset in two sub-datasets. Finally, I assessed for each sub-dataset the differences in genetic diversity between landscapes with different level of fragmentation and total habitat amount. The number of fragments had a neutral effect on the genetic diversity, supporting the habitat amount hypothesis. Moreover, the results suggest that all habitat fragments, even the small ones, are contributing to maintain the genetic diversity of the focal population. The species’ ecology, population dynamics and specific adaptations to a fragmented landscape might have led the Glanville fritillary butterfly to be especially resistant to fragmentation.

Research into animal emotions is important for improving animal welfare and understanding behavior. Emotional research also provides a better overview of ecology and helps from the point of view of protection. According to the consensus, animals feel different emotions and express their feelings in many ways. Emotional expression is also an important part of communication between animals. In my research, I wanted to study zoo visitors’ ability to interpret animals’ emotions. The study was conducted in Korkeasaari as a survey, where respondents were asked to rate animals’ valence and arousal based on short video clips. According to several theories, valence and arousal are two important dimensions of emotion. Interpretation is based on movements, expressions, and gestures of one animal or several animals. In my research, I used videos of Barbary macaque, Siberian tiger, and Markhor expressing different emotions. The aim of this study was to explore if there are differences in participants ratings between the species. In addition, I explored whether a specific emotion is interpreted better than others. I expected that, based on an evolutionary distance, the emotions of the Barbary macaque would be interpreted best despite the emotion. Secondly, I expected the best identification of negative Valence and high arousal, which would be important for evolution and survival. I found that the valence of the barbary macaque was interpreted best, but the arousal of the markhor was interpreted as well as the Barbary macaques. Different emotions were interpreted differently in each specie. The interpretation of emotions is also influenced by the participant’s demographic factors such as age and gender. Differences in ratings between the species may also be explained by species-specific factors such as the extent of the emotional scale to be expressed or need to express emotions. Together with other similar studies, the aim of this study is to improve animal welfare and to increase interest and knowledge of animal emotions.

Rapid environmental changes over the last 100 years have led to substantial range shifts across taxonomic groups. Understanding what facilitates successful shifts is important for predicting ecological consequences and planning efficient conservation actions. Interestingly, the very process of range expansion can affect the success of the shift by causing genetic changes in the expanding populations. Theory predicts that without sufficient gene flow, repeated founder events and strong genetic drift can result in allele frequency gradients and loss of genetic diversity along the expansion axis. Empirical studies testing these expectations in environment-driven range shifts are still relatively scarce, and how range expansions affect genetics in highly mobile species remains unclear. In this study, I investigated the genetic consequences of a recent range expansion in a long-distance migratory passerine, the reed warbler (Acrocephalus scirpaceus). Utilizing genome-wide data from restriction site-associated DNA sequencing (RAD-seq), I studied whether the expansion was reflected in either population structure or genetic diversity of the recently established Finnish range edge population. Despite philopatry and genetic differentiation to the range core populations, principal component analysis (PCA) and a model-based Bayesian clustering approach (fineRADstructure) revealed a lack of spatial population structure along a putative colonization route. Levels of genetic diversity, based on expected heterozygosity, nucleotide diversity, and private allele count, were found to be very similar between range edge (Finland) and range core (Central Europe). The results likely indicate high levels of gene flow both within the new population and across greater spatial distances during or after the range expansion. Due to a detected sequencing batch effect, however, the exact diversity estimates must be considered preliminary. These findings suggest that species with high enough dispersal propensity may escape the predicted genetic costs of range expansions, retaining high levels of genetic variation at range margins. This study provides valuable insights for understanding range shifts in mobile taxa, and highlights the need to investigate further the traits of species that enable the preservation of evolutionary potential during range shifts.

Animal welfare is a multifaceted concept that encompasses the overall well-being of animals, considering their physical and psychological health, behaviour, social interactions, and ability to engage in species-specific behaviours. Though there isn't a single universally accepted definition, the World Organisation for Animal Health (OIE) provides a widely recognized definition. According to the OIE, animal welfare refers to how well an animal copes with its living conditions. An animal is considered to have good welfare if it is healthy, comfortable, well-nourished, safe, able to express innate behaviour, and not suffering from pain, fear, or distress. In my thesis, the main objective is to identify knowledge gaps in recognizing factors that influence welfare among animal caretakers and to gather essential information that can serve as a foundation for future efforts to improve animal welfare in Korkeasaari Zoo. The project was conducted in collaboration with the zoo and involved studying and assessing the welfare of four different species. The assessments were based on scientific knowledge obtained through extensive literature research. The findings were then compared and analyzed by using a general linear model (GLM) with the zookeepers' own assessments. The results revealed that, overall, zookeepers tended to assess animal welfare more positively than the knowledge-based evaluation, although the extent of this difference varied among species. Notably, the results brought to light that certain species, especially the Asiatic lion, have specific welfare requirements that might not be fully recognized by the keepers. This implies there are opportunities for enhancing animal welfare in these cases. Furthermore, assessments varied depending on the type of question posed, with a significant observation being that nutritional requirements consistently received the highest evaluation across all species, regardless of the evaluator. This underscores the heightened attention that zookeepers pay to the nutritional well-being of the animals. This likely stems from the availability of well-documented nutritional information, in contrast to other facets of welfare in the studied species that might still be less comprehensively understood. My research is practical in nature, focusing on four specific species within one zoo. It may not primarily contribute to theoretical advancements but rather offer practical insights and applications. This marks just the starting point and indicates the need for further exploration and advancement. Shedding light on the various factors that shape animal welfare is pivotal for refining the operational protocols within the zoo setting. Such insights can pave the way for constructive measures that contribute to the betterment of the animals' well-being within the zoo environment. For instance, the notable difference in the evaluation of Asiatic lions, where the zookeepers scored them higher than the literature-based assessment, emphasizes the importance of incorporating scientific knowledge into zoo management practices. By bridging this gap and aligning assessments with well-established scientific data, we can make substantial strides in improving animal welfare in Zoos.

Flight collisions with buildings contribute to a significant proportion of human-related bird mortalities globally. However, the global scope of this phenomenon remains poorly studied and little is known about the vulnerability of European bird populations to glass collisions. Here I investigate the impact of bird-window collisions (BWCs) on bird populations in Finland by analyzing long-term ringed-bird data and complementing it with empirical findings from an on-site survey in an urban area. Specifically, I aimed to discern spatiotemporal and ecological patterns in collisions over the past 50 years at both national and local scales. I found that based on ringing recoveries, the probability of detecting collisions has decreased over time and there are distinct seasonal patterns, with collisions peaking during the spring and fall seasons. Most collisions have occurred in urban areas, with collision densities decreasing with degrees of urbanization. Notably, the White-backed Woodpecker (Dendrocopos leucotos), an endangered species in Finland, emerged as the most vulnerable species. Moreover, young, first-year birds collide at higher rates than adults, and habitat preference and foraging strata significantly influence species-specific collision risks. Specifically, species with open and aquatic habitat preferences collide at lower rates than species favoring urban and forested areas, while water-foraging birds collide less than species foraging at low and high levels. In my case study in Helsinki, I found 42 collisions over 21 days, with the House Sparrow (Passer domesticus), another endangered species in Finland, being the most common collider. A positive correlation was identified between site-specific collision rates and glass area, while vegetation cover had no significant effect on collisions. These findings shed light on critical species, temporal variations, and urban factors influencing BWCs at a national level, representing a crucial step in understanding and monitoring the threat posed by glass to Finland’s bird population. I propose a standardized survey procedure to further understand the extent of this issue in Finland, which will be essential in developing efforts to mitigate the adverse impact of human activities on wildlife.

During this study I examined the roles that resource diversity and trophic complexity play in the emergence and maintenance of biodiversity (ecological complexity) via the use of the evolutionary software Avida. I found a positive relationship between resource diversity and ecological complexity as would be expected from previous studies. However, a trade off was observed between ecological complexity and resource diversity, following the principle of diminishing returns. I also showed that trophic complexity exhibited a positive relationship with ecological complexity echoing what was described in previous studies. However, this increase in ecological complexity resulted in an increase in competition which slowed down the accumulation of higher resources which in-turn affected the emergence of higher-level functions. This study further suggests that an increase in ecological complexity results in an increase in ecosystem stability, however more rigorous measures are needed to fully establish this link. Despite, the inherent abstractions that are present in the Avida system, it has provided valuable insights into the relationships between these ecological factors. The findings suggest that there is need for more future studies possibly looking at the resilience and recovery of these ecosystems as this would be critical for understanding and addressing the current biodiversity crisis.

After drastic declines in large carnivores’ populations globally, conservation efforts have been successful, and predators’ populations are in recovery. However, their comeback has led to new interactions with locals, generating different conflicts. Two main approaches have been considered to mitigate these conflicts, those being the land sparing and land sharing models, however, the land sparing model requires great extents of protected areas, areas that in Europe are missing, therefore forcing a call for the land sharing model. In Finland, this approach has generated debates among different stakeholders, the outcomes of this debate shaping the fate for the four species: brown bear (Ursus arctos), grey wolf (Canis lupus), Eurasian lynx (Lynx lynx) and wolverine (Gulo gulo). Attitudes towards those species can be used to explore the drivers of the conflicts, however, only few studies have explored this context, considering the ecological and social dimension separately. In addition, the ecotourism industry has been recently recognized as a new stakeholder in the Finnish large carnivore’s context, but the effects of its activities were assessed only ecologically. Therefore, with this study I aimed to explore the attitudes of locals from a specific region of Finland towards the four large carnivores’ species, and to assess the different drivers of those species, through a combination of field questionnaires, social variables and large carnivores’ population data. I explored potential correlates of the differences in attitudes, adding also the spatial effect of ecotourism over the socio-ecological factors. I predicted attitudes to vary among species, having on one side the brown bear with positive attitudes, in contrast the wolf with negative attitudes, while neutral attitudes towards the lynx and wolverine. I also expected to find more negative attitudes in smaller localities rather than in localities with a greater human population density. Also, I explored whether the ecotourism activities have a positive or negative effect over the locals’ attitude towards carnivores, expecting the ecotourism industry to bring positive attitudes in nearby localities. As result, attitudes towards the four different species varied significantly, the attitudes towards each different species having different drivers, with the human population size being important for wolverines and wolves, while the status for bear and lynx populations. The ecotourism had an effect only on bear attitudes, being positively correlated (closer the ecotourism activities were, more positive the attitudes are). To mitigate the large carnivores-human conflict in Finland, a community approach is not the solution, since the different origins of the attitudes ‘drivers. However, the attitudes among species are positively correlated, consequently, by ameliorate the attitudes towards one species, also the others will benefit. Finally, by inducing a proper management within the ecotourism industry and promoting more the respective activity on a national level, the ecotourism can have a positive impact and get a positive role in the Finnish conflict.

Eläinten hyvinvoinnin parantamiseen tarvitaan paljon tieteellistä tutkimusta tunteista, älykkyydestä ja lajikohtaisista tarpeista. Tiedon pohjalta pystytään vertaamaan ja kehittämään eläinten tarpeisiin soveltuvia olosuhteita, kuten esimerkiksi virikkeitä ja hoitomuotoja eläintarhoissa. Eläintarhaolosuhteissa eläimen hyvinvoinnin saavuttaminen vaatii kompromisseja tilan ja resurssien rajallisuuden vuoksi. Parhaimman kompromissin löytämiseen vaaditaan tieteellistä tietoa lajikohtaisesta hyvinvoinnista. Maisterintutkielman tarkoituksena oli tuottaa tieteelliseen tietoon perustuva arvio Korkeasaaren eläintarhassa valittujen lajien hyvinvoinnista, jotka olivat huulipekari (Tayassu pecari), pikkumarmosetti (Cebuella pygmaea), punaniskakenguru (Macropus rufogriseus) ja sinikurkkuara (Ara glaucogularis). Tavoitteena oli tunnistaa tekijät, jotka vaikuttavat kyseisten eläinten hyvinvointiin luonnossa, ja verrata niitä eläintarhassa olevien yksilöiden olosuhteisiin. Tämän avulla pystyttiin arvioimaan lajikohtaiset tarpeet, joita tarvitaan eläinten hyvinvoinnin saavuttamiseksi. Vertasin hyvinvointiarvioitani tutkittavien lajien hoitajien tekemiin arvioihin, minkä tarkoituksena oli ymmärtää, riippuuko hyvinvoinnin arvio arvioijan näkökulmasta, ja onko lajien välillä eroja siinä, mihin seikkoihin arvioitsijat kiinnittävät huomiota. Arviointeja vertailemalla oli myös tarkoitus löytää tekijöitä, joilla on vaikutusta lajikohtaiseen hyvinvointiin Korkeasaaressa, minkä pohjalta voidaan ymmärtää ja kehittää mahdollisia hyvinvointia edistäviä toimenpiteitä. Toteutin tutkielman eri osioissa. Ensin suoritin kirjallisuuskatsauksen, jonka tarkoituksena oli määrittää tutkittavien lajien käyttäytyminen ja hyvinvoinnin tarpeet tieteellisten tutkimuksien avulla. Seuraavaksi selvitin eläinten olosuhteet Korkeasaaressa aitauksien kuvaamisen, tarkastelun ja hoitajien haastattelujen avulla. Tämän jälkeen tein hyvinvointikartoitukset, joita verrattiin tutkittavien eläinten hoitajien vastaaviin tilastollisesti. Hoitajat arvioivat lajien hyvinvoinnin aina paremmaksi kuin minä, ja erot arvioinneissa olivat suuria. Johtopäätöksenä voidaan pitää, että suora vertailu luonnonympäristöön voi johtaa huomattavasti alhaisempiin hyvinvointiarvioihin. Tällainen on esimerkiksi trooppisen ilmaston vertailu Suomen vuodenaikaisvaihteluun, vaikka eläimillä olisi aina mahdollisuus suotuisiin lämpö- ja valaistusolosuhteisiin. Hyvinvoinnin osa-alueiden välillä ei ollut merkittäviä eroja. Huomattavaa on, että hoitajat arvioivat samalla myös paitsi eläimen olosuhteita, myös omaa onnistumistaan niiden hoidossa. Tämä voi vaikuttaa siihen, että yksikään laji ei saanut hoitajilta yhtään 1-arviota, kun taas minulla oli objektiivisempi ote arviointiin, sillä kritiikki ei kohdistunut minuun edes välillisesti.

The intensification of agriculture is one of the main drivers of biodiversity loss worldwide. One of the intensification shifts has occurred from cattle grazing on biodiversity-rich semi-natural grasslands to ceased grazing or grazing on cultivated species-poor grasslands. While the effect of different grazing pressure on biodiversity in semi-natural grasslands has been studied extensively, little is known of how current grazing regimes on cultivated grasslands affect biodiversity and ecosystem services in different farming systems. Here, we investigated how arthropod abundance and potential ecosystem services are related to varying grazing pressure on cultivated grasslands at conventional and organic farms with meat or dairy production. We sampled aerial arthropods with sticky tape traps in four land-use types within the farms. Relative arthropod abundance was derived from the tapes using an imagery analysis, and the numbers of pollinators and predators from 4 taxonomic groups were counted. The results showed no difference in the relative arthropod abundance in relation to grazing pressure, but there was weak evidence for higher predator abundance at low and high grazing pressure. The relative arthropod abundance showed a positive trend in organic farms. However, pollinator abundance was higher in conventional farms, and predator abundance did not differ between farming systems. Land-use type was related to the occurrence of predators and pollinators: both groups had the lowest abundance in farmyards compared to cultivated pastures, silage fields, and cereal crop fields. Predator numbers were also higher in silage fields than in the other land-use types. However, there was no significant interaction between land-use types and farming systems in their effect on the arthropod groups. The results suggest that grazing pressure on cultivated grasslands has a minor or negligible impact on arthropod abundance in the two commonest farming systems. However, the effect of farming systems on relative arthropod abundance might be obscured by low sample sizes, high abundance of only a few species, and other variables not included here, such as the use of manure or pesticides. In addition, pollinators included only two taxonomic groups, potentially leading to results not applicable to all pollinators. Consequently, more large-scale studies with higher sample sizes and the inclusion of arthropod diversity and data on the key on-farm practices and landscape structure are needed to disentangle the relationship between biodiversity and grazing on cultivated grasslands in Finland.