Biology subjects

Iglesias-Carrasco, M.

Publications and source records attributed to Iglesias-Carrasco, M..

6 recordsLinked to original sources

bioRxiv2025

Drivers of avian genomic change revealed by evolutionary rate decomposition

Modern bird diversity spans a striking array of forms, behaviours, and ecological roles. Analyses of molecular evolutionary rates can reveal the links between genomic and phenotypic change, but disentangling the drivers of rate variation has been difficult across large numbers of whole-genomes. Using comprehensive estimates of traits and evolutionary rates across a family-level phylogeny of birds, we show that clutch size, generation length, and beak shape are dominant predictors of genome-wide mutation rates. To identify the major axes of evolutionary rate variation, we employ covariance matrix eigendecomposition from rates estimated for branches of the avian phylogeny and across genomic loci. We find that the majority of rate variation occurs along the terminal branches of the phylogeny associated with extant families of birds. Additionally, we use principal components analyses to show that several axes of variation are linked with rapid evolution in microchromosomes immediately after the Cretaceous-Palaeogene transition. These apparent pulses of evolution are consistent with major changes in evolutionary rates in the machineries for meiosis, heart performance, and RNA splicing, surveillance, and translation. They also correlate with the diversification of ecological niches reflected in increased tarsus length. Collectively, our analyses paint a nuanced picture of avian evolutionary rates through time, revealing that the ancestors of the most diverse lineages of birds underwent major genomic changes related to mutation, gene usage, and niche expansion near the beginning of the Palaeogene period.

evolutionary biology↗

bioRxiv2024

Deep learning from videography as a tool for measuring infection in poultry

Poultry farming is threatened by regular outbreaks of Escherichia coli (E. coli) that lead to significant economic losses and public health risks. However, traditional surveillance methods often lack sensitivity and scalability. Early detection of infected poultry using minimally invasive procedures is thus essential for preventing epidemics. To that end, we leverage recent advancements in computer vision, employing deep learning-based tracking to detect behavioural changes associated with E. coli infection in a case-control trial comprising two groups of 20 broiler chickens: (1) a healthy control group and (2) a group infected with a pathogenic E. coli field strain from the poultry industry. More specifically, kinematic features derived from deep learning-based tracking data revealed markedly reduced activity in the challenged group compared to the negative control. These findings were validated by lower mean optical flow in the infected flock, suggesting reduced movement and activity, and post-mortem physiological markers of inflammation which confirmed the severity of infection in the challenged group. Overall, this study demonstrates that deep learning-based tracking offers a promising solution for real-time monitoring and early infection detection in poultry farming, with the potential to help reduce economic losses and mitigate public health risks associated with infectious disease outbreaks in poultry.

animal behavior and cognition↗

bioRxiv2021

Effects of early and late life environments on ageing

Early and late life environments can interact in complex ways to influence the fitness of individuals. Most studies investigating effects of the environment on fitness focus on environments experienced and traits expressed at a single point in an organisms life. However, environments vary with time, thus the environments organisms experience at different ages may interact to affect how traits change throughout life. Here, we test whether thermal stress experienced during development leads individuals to cope better with thermal stress as adults. We manipulated temperature during both development and adulthood and measured a range of life-history traits, including senescence, in male and female seed beetles, Callosobruchus maculatus. We found that favourable developmental conditions increased reproductive performance of females (i.e. silver-spoon effects). In contrast, non-reproductive traits such as lifespan and survival senescence were only affected by adult environments- high adult temperatures decreased longevity and survival. Additionally, developmental and adult environments interacted to affect age-dependent changes in male weight. Overall, our results show that effects of early and late environments can be both sex- and trait- specific, and that a full understanding of how environments interact to affect fitness and ageing requires the integrated study of conditions experienced during different stages of ontogeny.

evolutionary biology↗

bioRxiv2020

Sex-specific effects of developmental density on life history and age-dependent flight traits

The environment organisms experience during development can have effects which carry over into their adult lives. These developmental environments may not only affect adult traits at a given point in time, but also how these traits change with age. Generally, stressful developmental environments can lead to sub-optimal adult fitness traits and a faster deterioration of these traits with age. But whether these environments affect how performance traits change with age or whether they affect males and females differently lacks evidence. Here, we test the sex-specific effects of crowding during development on life history traits such as lifespan, fecundity, age-dependent survival, and reproductive senescence, as well as flight performance traits, in the seed beetle-Callosobruchus maculatus. We show that although developmental crowding has no effect on flight performance of either sex, on male adult lifespan, or on female age-dependant survival, it is detrimental to female lifespan and fecundity, as well as female age-dependent reproduction. Additionally, we show that flight traits can change with age and differ between males and females, which may be reflective of sex-specific life-histories and behaviour. Our study has implications for understanding how developmental environments affect life history and behavioural strategies of both males and females.

evolutionary biology↗

bioRxiv2020

The role of maternal effects on offspring performance in familiar and novel environments

Maternal effects are an important evolutionary force that may either facilitate adaptation to a new environment or buffer against unfavourable conditions. The degree of variation in traits expressed by siblings from different mothers is frequently sensitive to environmental conditions. This could generate a Maternal-by-Environment interaction (MxE) that could inflate estimates of Genotype-by-Environment effects (GxE). We aimed to test for environment-specific maternal effects (MxE) using a paternal full-sib/half-sib breeding design in the seed beetle Callosobruchus maculatus, where we split and reared offspring from the same mother on two different bean host types - original and novel. Our quantitative genetic analysis indicated that maternal effects were very small on both host types for all the measured life-history traits. There was also little evidence that maternal oviposition preference for a particular host type predicted her offsprings performance on that host. Further, additive genetic variance for most traits was relatively high on both hosts. While there was higher heritability for offspring reared in the novel host, there was no evidence for GxEs, and most cross-host genetic correlations were positive. This suggests that offspring from the same family ranked similarly for performance on both host types. Our results point to a genetic basis of host adaptation in the seed beetle, rather than maternal effects. Even so, we encourage researchers to test for potential MxEs because, due to a lack of testing, it remains unclear how often they arise.

evolutionary biology↗

bioRxiv2020

Urban colonization is driven by a mixture of evolutionarily conserved and labile traits

Urbanization is a fast and dramatic transformation of habitat that generally forces native fauna into novel ecological challenges. The biological prerequisites necessary to establish in urban areas have been widely studied, but the macroevolutionary characteristics of traits that allow urban colonization remain poorly understood. Urban colonization might be facilitated by traits that are evolutionarily conserved and which lead to a diversity of closely related species. Alternatively, urban colonization might be associated with labile traits that frequently arise and are lost. In a large data set from passerine birds, we find that urban colonization has a signal of highly labile traits, despite many traits associated with colonization being highly conserved. Urban colonization is associated with traits that allow faster speciation than non-urban-colonizing counterparts, and more frequently transition to non-urban trait states than in the opposite direction. Overall, the traits that facilitate urban colonization are a mix of highly conserved and labile traits and appear to provide an evolutionarily successful strategy.

evolutionary biology↗