Chromatin Unlimited: An Evolutionary View of Chromatin

Chromatin is a fundamental and highly conserved structure that carries genetic and epigenetic information in eukaryotic cells [...]

Phylogenetic Analysis of the Membrane Attack Complex/Perforin Domain-Containing Proteins in Gossypium and the Role of GhMACPF26 in Cotton Under Cold Stress

The membrane attack complex/perforin (MACPF) domain-containing proteins are involved in the various developmental processes and in responding to diverse abiotic stress. The function and regulatory network of the MACPF genes are rarely reported in Gossypium spp. We study the detailed identification and partial functional verification of the members of the MACPF family. Totally, 100 putative MACPF proteins containing complete MACPF domain were identified from the four cotton species. They were classified into three phylogenetic groups and underwent multifold pressure indicating that selection produced new functional differentiation. Cotton MACPF gene family members expanded mainly through the whole-genome duplication (WGD)/segmental followed by the dispersed. Expression and cis-acting elements analysis revealed that MACPFs play a role in resistance to abiotic stresses, and some selected GhMACPFs were able to respond to the PEG and cold stresses. Co-expression analysis showed that GhMACPFs might interact with valine-glutamine (VQ), WRKY, and Apetala 2 (AP2)/ethylene responsive factor (ERF) domain-containing genes under cold stress. In addition, silencing endogenous GhMACPF26 in cotton by the virus-induced gene silencing (VIGS) method indicated that GhMACPF26 negatively regulates cold tolerance. Our data provided a comprehensive phylogenetic evolutionary view of Gossypium MACPFs. The MACPFs may work together with multiple transcriptional factors and play roles in acclimation to abiotic stress, especially cold stress in cotton.

Marine gregarine genomes illuminate current understanding of apicomplexan glideosome

Apicomplexans, parasite protists of a very wide diversity of metazoan hosts, are mostly known from species infecting human. Absence or limited data for basal lineages prevents a comprehensive view of evolutionary history and adaptive capacities of Apicomplexa. Here, we characterized the genome of the marine eugregarine Porospora gigantea, remarkable for the gigantic size of its vegetative feeding forms (trophozoites) and their speed of gliding movement, the fastest so far recorded for an Apicomplexa. Not a single but two highly related genomes named A and B were assembled. Highly syntenic, of similar size (9 Mb) and coding capacities (~5300 genes), they display a 10.8% divergence at nucleotide level corresponding to 16-38 My divergent time. Orthogroups analyses across 25 (proto)Apicomplexa including Gregarina niphandrodes showed that A and B are highly divergent from all other known apicomplexan species, revealing an unexpected diversity. These two related species branch in phylogenetic studies at the base of Cephaloidophoroidea, forming a new family in these crustacean gregarines. Gliding proteins data mining found a strong conservation of actin-related proteins, as well as of regulatory factors, within apicomplexan. In contrast, the conservation of core glideosome proteins and adhesion proteins appears to be highly variable among apicomplexan lineages, especially in gregarines. These results confirm the importance of studying gregarines to widen our biological and evolutionary view of apicomplexan parasites, to better apprehend species diversity and revise our understanding of the molecular bases of some key functions such as observed for the glideosome.

Social evolution as moral truth tracking in natural law

Morality can be adaptive or maladaptive. From this fact come polarizing disputes on the meta-ethical status of moral adaptation. The realist tracking account of morality claims that it is possible to track objective moral truths and that these truths correspond to moral rules that are adaptive. In contrast, evolutionary anti-realism rejects the existence of moral objectivity and thus asserts that adaptive moral rules cannot represent objective moral truths, since those truths do not exist. This article develops a novel evolutionary view of natural law to defend the realist tracking account. It argues that we can identify objective moral truths through cultural group selection and that adaptive moral rules are likely to reflect such truths.

Bridging the Gap Between Mammal and Insect Ears – A Comparative and Evolutionary View of Sound-Reception

Insects must wonder why mammals have ears only in their head and why they evolved only one common principle of ear design—the cochlea. Ears independently evolved at least 19 times in different insect groups and therefore can be found in completely different body parts. The morphologies and functional characteristics of insect ears are as wildly diverse as the ecological niches they exploit. In both, insects and mammals, hearing organs are constrained by the same biophysical principles and their respective molecular processes for mechanotransduction are thought to share a common evolutionary origin. Due to this, comparative knowledge of hearing across animal phyla provides crucial insight into fundamental processes of auditory transduction, especially at the biomechanical and molecular level. This review will start by comparing hearing between insects and mammals in an evolutionary context. It will then discuss current findings about sound reception will help to bridge the gap between both research fields.

Social Evolution as Moral Truth Tracking in Natural Law

Morality can be adaptive or maladaptive. From this fact come polarising disputes on the meta-ethical status of moral adaptation. The realist tracking account of morality claims that it is possible to track objective moral truths and that these truths correspond to moral rules that are adaptive. In contrast, evolutionary anti-realism rejects the existence of moral objectivity and thus asserts that adaptive moral rules cannot represent objective moral truths, since those truths do not exist. This article develops a novel evolutionary view of natural law to defend the realist tracking account. It argues that we can identify objective moral truths via cultural group selection and that adaptive moral rules are likely to reflect such truths.

An Evolutionary View of the U.S. Supreme Court

The voting patterns of the nine justices on the United States Supreme Court continue to fascinate and perplex observers of the Court. While it is commonly understood that the division of the justices into a liberal branch and a conservative branch inevitably drives many case outcomes, there are finer, less transparent divisions within these two main branches that have proven difficult to extract empirically. This study imports methods from evolutionary biology to help illuminate the intricate and often overlooked branching structure of the justices’ voting behavior. Specifically, phylogenetic tree estimation based on voting disagreement rates is used to extend ideal point estimation to the non-Euclidean setting of hyperbolic metrics. After introducing this framework, comparing it to one- and two-dimensional multidimensional scaling, and arguing that it flexibly captures important higher-dimensional voting behavior, a handful of potential ways to apply this tool are presented. The emphasis throughout is on interpreting these judicial trees and extracting qualitative insights from them.