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Topic Review
TH Signalling in Human Evolution
Thyroid hormone (TH) signalling is a universally conserved pathway with pleiotropic actions that is able to control the development, metabolism, and homeostasis of organisms. TH signalling has likely played a critical role in human evolution by facilitating the adaptive responses of early hominids to unprecedently challenging and continuously changing environments.
  • 755
  • 30 Dec 2021
Topic Review
Fundamental/Longitudinal Life History Trade-Offs on Delay Discounting
Delay discounting (DD) was a product of two distinct life history trade-offs, reflecting both the trait-like quality and age-related development.  
  • 733
  • 05 May 2022
Topic Review
Membrane Structure Obtained in an Experimental Evolution Process
The functionalized vesicle membrane is a product of the evolution process and is connected to several survival mechanisms. An octapeptide (KSPFPFAA) is identified which rapidly integrated into the vesicle membrane and is obviously connected to a particular advantage of the corresponding functionalized vesicle according to its significant accumulation.
  • 724
  • 09 Feb 2022
Topic Review
Eumelanin in the Living World
A lot of still unexplained aspects characterize eumelanin, a macromolecule able to play in living organisms several, sometimes conflicting, roles. This contribution aims  to emphasize the unique characteristics and the consequent unusual behaviors of a molecule that in an evolutionary context survived natural selection and still holds the main chemical/physical features detected in fossils dating to the late Carboniferous. 
  • 704
  • 29 May 2023
Topic Review
Innate Immunity in Disease and Adaptation to Stress
Since first being documented in ancient times, the relation of inflammation with injury and disease has evolved in complexity and causality. Early observations supported a cause (injury) and effect (inflammation) relationship, but the number of pathologies linked to chronic inflammation suggests that inflammation itself acts as a potent promoter of injury and disease. Additionally, results from studies over the last decades point to chronic inflammation and innate immune signaling as a critical link between stress (exogenous and endogenous) and adaptation.
  • 700
  • 06 Jun 2022
Topic Review
Responses of Humans to Space Flight in LEO
Homo sapiens and their predecessors evolved in the context of the boundary conditions of Earth, including a 1 g gravity and a geomagnetic field (GMF). These variables, plus others, led to complex organisms that evolved under a defined set of conditions and define how humans will respond to space flight, a circumstance that could not have been anticipated by evolution. Over the past ~60 years, space flight and living in low Earth orbit (LEO) have revealed that astronauts are impacted to varying degrees by such new environments. In addition, it has been noted that astronauts are quite heterogeneous in their response patterns, indicating that such variation is either silent if one remained on Earth, or the heterogeneity unknowingly contributes to disease development during aging or in response to insults. 
  • 699
  • 30 Mar 2023
Topic Review
Transgenderizations of the Collective Psyche of Humanity
The evolving collective psyche of humanity reveals a shift from predominantly masculine to increasingly feminine characteristics since around 1500 A.D. This transformation, termed 'transgenderization,' is attributed to identified psychological factors. Remarkably, the collective psyche has undergone similar transitions in the past since the emergence of humanity.
  • 667
  • 21 Feb 2024
Topic Review
Reactive Oxygen Species Signaling Pathways
Early in an evolutionary transition, bioenergetics and reactive oxygen species (ROS) may play a large role in managing these evolutionary conflicts. Chemiosmosis can be thought of as a poorly insulated wire—when supply exceeds demand, electrons are cast off and can form ROS. ROS signaling may thus lead to the dispersal of the excess products into the environment. These products may lead to groups and the formation of higher-level units that can subsequently be targeted by selection.
  • 655
  • 26 Jul 2022
Topic Review
Retrovirus-Derived RTL/SIRH Genes in Eutherian Developmental System
Eutherians have 11 retrotransposon Gag-like (RTL)/sushi-ichi retrotransposon homolog (SIRH) genes presumably derived from a certain retrovirus. Accumulating evidence indicates that the RTL/SIRH genes play a variety of roles in the mammalian developmental system, such as in the placenta, brain, and innate immune system, in a eutherian-specific manner. It has been shown that the functional role of Paternally Expressed 10 (PEG10) in placental formation is unique to the therian mammals, as are the eutherian-specific roles of PEG10 and PEG11/RTL1 in maintaining the fetal capillary network and the endocrine regulation of RTL7/SIRH7 (aka Leucine Zipper Down-Regulated in Cancer 1 (LDOCK1)) in the placenta. In the brain, PEG11/RTL1 is expressed in the corticospinal tract and hippocampal commissure, mammalian-specific structures, and in the corpus callosum, a eutherian-specific structure. Unexpectedly, at least three RTL/SIRH genes, RTL5/SIRH8, RTL6/SIRH3, and RTL9/SIRH10, play important roles in combating a variety of pathogens, namely viruses, bacteria, and fungi, respectively, suggesting that the innate immunity system of the brain in eutherians has been enhanced by the emergence of these new components. 
  • 584
  • 25 Oct 2023
Topic Review
Directed Cycles Evolve with Junk DNA
Cell responses are usually viewed as transitive events with fixed inputs and outputs that are regulated by feedback loops. In contrast, directed cycles (DCs) have all nodes connected, and the flow is in a single direction. Consequently, DCs can regenerate themselves and implement intransitive logic. DCs are able to couple unrelated chemical reactions to each edge. The output depends upon which node is used as input.
  • 562
  • 22 Nov 2023
Topic Review
Genetic Requirement for Minimal Genome
Genome reduction is a top-down approach to achieve the minimal genetic information essential for a living cell. Exploring the minimal genetic requirements for cells to maintain free living is an exciting topic in biology. Multiple approaches are employed to address the question of the minimal genome. In addition to constructing the synthetic genome in the test tube, reducing the size of the wild-type genome is a practical approach for obtaining the essential genomic sequence for living cells. The well-studied Escherichia coli has been used as a model organism for genome reduction owing to its fast growth and easy manipulation.
  • 557
  • 06 Sep 2023
Topic Review
Chromosome Evolution in Birds: Molecular Cytogenetics, Comparative Genomics and Whole Genome Assemblies
Contemporary iterations of avian phylogenies based on multiple genome sequence assemblies assign three major clades: Palaeognathae (mostly ratite birds), Galloanseres (land and waterfowl) and the largest group—Neoaves. The latter two are sister clades representing subdivisions of Neognathae, while Neoaves further subdivide into Columbaves (pigeons/doves/cuckoos/bustards, etc.), Mirandornithes (flamingos/grebes), Telluraves (“higher land birds”, including finches) and the newly recognized Elementaves (e.g., penguins/pelicans/hummingbirds/swifts/cranes/shorebirds). Molecular studies provide clade information, likely divergence timings and a framework from which gross genomic (chromosomal) changes may be mapped. In this review, we consider the patterns of chromosome change that have occurred throughout all avian clades thus far examined, citing studies from standard karyotyping through molecular cytogenetics to whole genome assemblies. Standard karyotyping led to the realization that most chromosomes (particularly the microchromosomes and dot chromosomes) could not be distinguished by classical means. Indeed, cross-species comparisons were difficult, even among the macrochromosomes, because of indistinct banding patterns. Based on fluorescence (or fluorescent) in situ hybridization (FISH), comparative genomics was thence progressed considerably by cross-species chromosome painting (Zoo-FISH) for the macrochromosomes and interspecific mapping of bacterial artificial chromosome (BAC) probes for the microchromosomes. A key finding was that the most studied species, the chicken, fortuitously, has a genomic organization somewhat akin to that of the ancestral karyotype and tends to be the standard from which all others are measured. A notable exception is the fusion of basal chromosome 4 with a smaller chromosome that convergently appears in some other Galliformes, at least one goose and one dove species. While some groups such as Falconiformes (falcons, etc.) and Psittaciformes (parrots, etc.) underwent extensive interchromosomal change, most, broadly speaking, retain a basic karyotype that differs little from bird to bird. Many, e.g., Passeriformes (finches, songbirds, etc.) and Columbiformes (pigeons, doves), do this despite multiple intrachromosomal rearrangements. The complete karyotype and fully established chromosome-level genome assembly of the chicken allow full integration of DNA sequence assembly with karyotype. They further permit cytogenetic studies to be performed using genome assemblies alone alongside cutting-edge long-read sequencing and optical mapping without the need for chromosome preparation. The classic ZW sex-determination system of birds is easily visible in most Neognathae species, but intrachromosomal change in the sex chromosomes is faster than in the autosomes; indeed, there are numerous examples of autosomal fusions and new sex chromosomes formed. Sex chromosomes aside, the classic avian karyotype represents a very successful mode of genome organization established before the emergence of the dinosaurs and perpetuated to this day in their only living descendants.
  • 2
  • 24 Jun 2026
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