Phylogenetic patterns and the underlying speciation processes can be deduced from morphological, functional, and ecological patterns of species similarity and divergence. In some cases, though, species retain multiple similarities and remain almost indistinguishable; in other cases, evolutionary convergence can make such patterns misleading; very often in such cases, the "true" picture only emerges from carefully built molecular phylogenies, which may come with major surprises. In addition, closely related species may experience gene flow after divergence, thus potentially blurring species delimitation. By means of advanced inferential methods, we studied molecular divergence between species of the genus (Myristicaceae): widespread and recently described, endemic , using widespread as a more distantly related outgroup with different ecology and morphology-although with overlapping range. Contrary to expectations, we found that the latter, and not , was sister to . Therefore, probably diverged from through a recent morphological and ecological shift, which brought it close to distantly related . Through the modeling of the divergence process, we inferred that gene flow between and . stopped soon after their divergence and resumed later, in a classical secondary contact event which did not erase their ecological and morphological differences. While we cannot exclude that initial divergence occurred in allopatry, current species distribution and the absence of geographical barriers make complete isolation during speciation unlikely. We tentatively conclude that (a) it is possible that divergence occurred in allopatry/parapatry and (b) secondary contact did not suppress divergence.
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http://dx.doi.org/10.1002/ece3.6227 | DOI Listing |
Hum Mol Genet
January 2025
Department of Cell & Developmental Biology, Vanderbilt University School of Medicine, 1161 21st Ave S, Nashville, Tennessee, 37232, United States of America.
Tuberous Sclerosis Complex (TSC) is a debilitating developmental disorder characterized by a variety of clinical manifestations. While benign tumors in the heart, lungs, kidney, and brain are all hallmarks of the disease, the most severe symptoms of TSC are often neurological, including seizures, autism, psychiatric disorders, and intellectual disabilities. TSC is caused by loss of function mutations in the TSC1 or TSC2 genes and consequent dysregulation of signaling via mechanistic Target of Rapamycin Complex 1 (mTORC1).
View Article and Find Full Text PDFCan J Kidney Health Dis
January 2025
Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Canada.
Background: The COVID-19 pandemic and its accompanying safeguards intensified many of the ongoing daily challenges faced by caregivers of young people with chronic kidney disease (CKD) both pre-transplant and post-transplant, and also created a variety of new and pressing concerns. Little is known about how these families managed this unexpected adversity in their lives.
Objective: To evaluate change in psychosocial risk for families of young people with CKD during the COVID-19 pandemic health emergency from the perspective of caregivers.
Do machines and humans process language in similar ways? Recent research has hinted at the affirmative, showing that human neural activity can be effectively predicted using the internal representations of language models (LMs). Although such results are thought to reflect shared computational principles between LMs and human brains, there are also clear differences in how LMs and humans represent and use language. In this work, we systematically explore the divergences between human and machine language processing by examining the differences between LM representations and human brain responses to language as measured by Magnetoencephalography (MEG) across two datasets in which subjects read and listened to narrative stories.
View Article and Find Full Text PDFFront Cell Neurosci
January 2025
School of Veterinary Medicine, Institute of Pharmacology and Toxicology, Freie Universität Berlin, Berlin, Germany.
Infections impacting the central nervous system (CNS) constitute a substantial predisposing factor for the emergence of epileptic seizures. Given that epilepsy conventionally correlates with hippocampal sclerosis and neuronal degeneration, a potentially innovative avenue for therapeutic intervention involves fostering adult neurogenesis, a process primarily occurring within the subgranular zone of the dentate gyrus (DG) through the differentiation of neural stem cells (NSC). While experimental seizures induced by chemoconvulsants or electrical stimulation transiently enhance neurogenesis, the effects of encephalitis and the resultant virus-induced seizures remain inadequately understood.
View Article and Find Full Text PDFProc Biol Sci
January 2025
Centre for Functional Biodiversity, University of KwaZulu-Natal, Pietermaritzburg 3209, South Africa.
Ecological niche shifts are a key driver of phenotypic divergence and contribute to isolating barriers among lineages. For many groups of organisms, the history of these shifts and associated trait-environment correlations are well-documented at the macroevolutionary level. However, the processes that generate these patterns are initiated below the species level, often by the formation of ecotypes in contrasting environments.
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