Biology subjects

Lundgren, E. J.

Publications and source records attributed to Lundgren, E. J..

5 recordsLinked to original sources

bioRxiv2026

Music exposure reduces anxiety- and depression-like behavior in rodents: a systematic review and multilevel meta-analysis

Anxiety and depressive disorders impose a major global burden, prompting interest in non-pharmacological interventions that may influence affective processes. Music exposure has often been reported to affect anxiety- and depression-like behaviors, but preclinical findings remain heterogeneous and have not been quantitatively synthesized. Prior work has also focused almost entirely on mean behavioral responses, largely overlooking inter-individual variability as a biologically meaningful dimension. We conducted a preregistered systematic review and multilevel meta-analysis of experimental studies testing music exposure in laboratory rodents. Following PRISMA and PRISMA-EcoEvo guidelines, we synthesized 298 effect sizes from 20 studies using multilevel models to account for non-independence among effect sizes. We quantified effects on mean behavior with the log response ratio (lnRR) and effects on variability with the log variability ratio (ln V R). Overall, music exposure was associated with a statistically significant reduction in anxiety- and depression-like behaviors, corresponding to an average decrease of about 18% relative to controls. This mean effect was detected across outcome types and life stages despite substantial heterogeneity. By contrast, music exposure did not produce a statistically significant overall change in inter-individual behavioral variability. Instead, variability responses were context dependent: behavioral assay type and music meta-genre significantly moderated ln V R, with anxiety-like assays tending to show increased variability and depression-like assays tending to show reduced variability under music exposure. These results suggest that music exposure reliably shifts average affect-related behavior without uniformly changing behavioral stability across individuals. Because the evidence comes mainly from short-term exposures in young adult laboratory rodents, generalization beyond similar contexts should remain cautious.

animal behavior and cognition↗

bioRxiv2024

Trade-offs beget trade-offs: Causal analysis of mammalian population dynamics

Survival and reproduction strategies in mammals are determined by trade-offs between life history traits. In turn, the unique configuration of traits that characterize mammalian species give rise to species-specific population dynamics. The dependence of population dynamics on life history has been primarily studied as the relationship between population density and size-related traits. With the recent accumulation of genomic data, the effective population size (Ne) over million-year timescales has become quantifiable for a large proportion of mammal species. Using phylogenetic path analysis, we compared the dependence of population density and Ne on eleven traits that characterize mammalian allometry, diet and reproduction. We found variable impacts of traits on the two metrics of population dynamics across different classifications of mammalian species. For example, we found a negative association between brain size and both population density and Ne overall, but brain size was positively associated with Ne in carnivorans. Dietary specialization had a negative effect on population density, especially in ungulates. Ne of ungulates and primates was strongly affected by time to maturity and weaning age, respectively, highlighting the difference in reproductive strategy between these orders. The relationship between Ne and adult mass showed a gradient in association strength from cold to warm biomes. Together, our findings demonstrate that trade-offs not only characterize life-history evolution, but also extend across different metrics of population dynamics and vary among species groups. This challenges the static nature of the "energetic equivalence" rule and has major implications for selecting appropriate metrics for species conservation and restoration strategies.

evolutionary biology↗

bioRxiv2023

Preventing extinction in an age of species migration and planetary change

International and national conservation policies almost exclusively focus on conserving species in their historic native ranges, thus excluding species that have dispersed on their own accord or have been introduced by people. Given that many of these migrant species are threatened in their native ranges, conservation goals that explicitly exclude these migrant populations may overlook opportunities to prevent extinctions and respond dynamically to rapidly changing environmental and climatic conditions. Focusing on terrestrial mammals, we quantified the extent to which migration, in this case via introductions, has provided new homes for threatened mammal species. We then devised alternative scenarios for the inclusion of migrant populations in mainstream conservation policy with the aim of preventing global species extinctions and used spatial prioritization algorithms to simulate how these scenarios could change global spatial conservation priorities. We found that 22% of all identified migrant mammals (70 species) are threatened in their native ranges, mirroring the 25% of all mammals that are threatened. Reassessing global threat statuses by combining native and migrant ranges reduced the threat status of 23 species ([~]33% of threatened migrants). Thus, including migrant populations in threat assessments provides a more accurate assessment of actual global extinction risk among species. Spatial prioritization simulations showed that reimagining the role of migrant populations to prevent global species extinction could increase the importance of overlooked landscapes, particularly in central Australia. Our results indicate that these various and non-exhaustive ways to consider migrant populations, with due consideration for potential conservation conflicts with resident taxa, may provide unprecedented opportunities to prevent species extinctions. We present these alternatives and spatial simulations to stimulate discussion on how conservation ought to respond, both pragmatically and ethically, to rapid environmental change in order to best prevent extinctions.

ecology↗

bioRxiv2022

Worldwide late-Quaternary population declines in extant megafauna are due to Homo sapiens rather than climate

The worldwide loss of large animal species over the past 100,000 years is evident from the fossil record, with climate and human impact as the most likely causes of megafauna extinctions. To help distinguish between these two scenarios, we analysed whole-genome sequence data of 142 species to infer their population size histories during the Quaternary. We modelled differences in population dynamics among species using ecological factors, paleoclimate and human presence as covariates. We report a significant population decline towards the present time in more than 90% of species, with larger megafauna experiencing the strongest decline. We find that population decline became ubiquitous approximately 100,000 years ago, with the majority of species experiencing their lowest population sizes during this period. We assessed the relative impact of climate fluctuations and human presence on megafauna dynamics and found that climate has limited explanatory power for late-Quaternary shifts in megafauna population sizes, which are largely explained by Homo sapiens arrival times. As a consequence of megafauna decline, total biomass and metabolic input provided by these species has drastically reduced to less than 25% compared to 100,000 years ago. These observations imply that the worldwide expansion of H. sapiens caused a major restructuring of ecosystems at global scale.

evolutionary biology↗

bioRxiv2021

Echoes of the late Pleistocene in a novel trophic cascade between cougars and feral donkeys

Introduced large herbivores have partly filled ecological gaps formed in the late Pleistocene, when many of the Earths megafauna were driven extinct. However, surviving predators are widely considered unable to influence introduced megafauna, leading them to exert unusually strong herbivory and disturbance-related effects. We report on a behaviorally-mediated trophic cascade between cougars (Puma concolor) and feral donkeys (Equus africanus asinus) at desert wetlands in North America. In response to predation of juveniles, donkeys shifted from nocturnal to almost exclusively diurnal, thereby avoiding peaks in cougar activity. Furthermore, donkeys reduced the time they spent at desert wetlands by 87%: from 5.5 hours a day to 0.7 hours at sites with predation. These shifts in activity were associated with increased activity and richness of other mammal species and reduced disturbance and herbivory-related effects on these ecologically-distinct wetland ecosystems, including 49% fewer trails, 35% less trampled bare ground, and 227% more canopy cover. Cougar predation on introduced donkeys rewires an ancient food web, with diverse implications for modern ecosystems.

ecology↗