Evolutionary Conservatism Research Articles

Molecular-structural homology of proteolytic enzymеs in the studying of proteolysis mechanism and its regulation

The actual problem of experimental medicine is the substantiation of new model organisms that meet modern requirements of bioethics, cost and conditions of detention. The aim of this work was a comparative analysis of the homology degree of proteolytic enzymes in humans and pulmonary freshwater mollusks. The homology of enzymes in nucleotide sequences in humans and pulmonary freshwater mollusks in the analysis of unregulated proteolysis is 66–68 %; regulated proteolysis – 69–76 %; ubiquitin-like modifiers – 78–83 %; extracellular enzymes – 67–76 %; and intracellular enzymes – 65–72 %. The evolutionary conservatism of proteolytic enzymes and the presence of an open blood circulation, which allows the substances under study to be delivered from the hemolymph directly to target cells, make it possible to use these animals as cheap and convenient test organisms. The practical importance of a sufficiently high homology degree of proteolytic enzymes in humans and pulmonary freshwater mollusks justifies the expediency of forming mollusk aquaculture to obtain proteolytic enzyme protein preparations from their tissues within the framework of the tasks of biopharmaceuticals, cosmetics and the food industry.

Identification and Characterization of the Amphioxus Lck and Its Associated Tyrosine Phosphorylation-Dependent Inhibitory LRR Receptor.

Amphioxus (e.g., Branchiostoma belcheri, Bb) has recently emerged as a new model for studying the origin and evolution of vertebrate immunity. Mammalian lymphocyte-specific tyrosine kinase (Lck) plays crucial roles in T cell activation, differentiation and homeostasis, and is reported to phosphorylate both the ITIM and ITSM of PD-1 to induce the recruitment of phosphatases and thus the inhibitory function of PD-1. Here, we identified and cloned the amphioxus homolog of human Lck. By generating and using an antibody against BbLck, we found that BbLck is expressed in the amphioxus gut and gill. Through overexpression of BbLck in Jurkat T cells, we found that upon TCR stimulation, BbLck was subjected to tyrosine phosphorylation and could partially rescue Lck-dependent tyrosine phosphorylation in Lck-knockdown T cells. Mass spectrometric analysis of BbLck immunoprecipitates from immunostimulants-treated amphioxus, revealed a BbLck-associated membrane-bound receptor LRR (BbLcLRR). By overexpressing BbLcLRR in Jurkat T cells, we demonstrated that BbLcLRR was tyrosine phosphorylated upon TCR stimulation, which was inhibited by Lck knockdown and was rescued by overexpression of BbLck. By mutating single tyrosine to phenylalanine (Y-F), we identified three tyrosine residues (Y539, Y655, and Y690) (3Y) of BbLcLRR as the major Lck phosphorylation sites. Reporter gene assays showed that overexpression of BbLcLRR but not the BbLcLRR-3YF mutant inhibited TCR-induced NF-κB activation. In Lck-knockdown T cells, the decline of TCR-induced IL-2 production was reversed by overexpression of BbLck, and this reversion was inhibited by co-expression of BbLcLRR but not the BbLcLRR-3YF mutant. Sequence analysis showed that the three tyrosine-containing sequences were conserved with the tyrosine-based inhibition motifs (ITIMs) or ITIM-like motifs. And TCR stimulation induced the association of BbLcLRR with tyrosine phosphatases SHIP1 and to a lesser extent with SHP1/2. Moreover, overexpression of wild-type BbLcLRR but not its 3YF mutant inhibited TCR-induced tyrosine phosphorylation of multiple signaling proteins probably via recruiting SHIP1. Thus, we identified a novel immunoreceptor BbLcLRR, which is phosphorylated by Lck and then exerts a phosphorylation-dependent inhibitory role in TCR-mediated T-cell activation, implying a mechanism for the maintenance of self-tolerance and homeostasis of amphioxus immune system and the evolutionary conservatism of Lck-regulated inhibitory receptor pathway.

Comments on Wojciech Dzieduszycki’s Reflections on the State and Law

<p>Conservatives in Galicia during the Austro-Hungarian monarchy exerted an overwhelming influence on political and social life. Among the conservative groups and parties, there were the so-called Podolaks, to which Wojciech Dzieduszycki belonged, writer, politician and philosopher. He wrote about the genesis and concept of law, the functions of the state and the scope of state power. He spoke against the law that regulates all manifestations of human life, because social relations are also regulated by moral and religious norms. Dzieduszycki was critical of socialism and all excessive forms of state intervention because he was against excessive state power. Based on Dzieduszycki’s reflections on the state and law, it can be concluded that he was an advocate of evolutionary conservatism.</p>

Genome-wide identification of interleukin-17 (IL-17) / interleukin-17 receptor (IL- 17R) in turbot (Scophthalmus maximus) and expression pattern analysis after Vibrio anguillarum infection

Interleukin-17 (IL-17) is a cytokine secreted by a variety of immune cells that plays an important role in host defense against pathogens. IL-17 usually activates downstream immune signaling pathway by binding to heterodimeric or homodimeric complex formed by IL-17 receptors (IL-17R). Describing the characteristics, tissue distribution of IL-17 and IL-17 receptor family members and their expression after pathogen infection will provide a reference for host defense against disease of turbot. In this study, six IL-17 family members and nine IL-17 receptor family members were identified by analyzing the turbot (Scophthalmus maximus) genome. Different from other vertebrates, most members of the IL-17 receptor family own two copies. Protein structure analysis showed that the six IL-17 family members contained typical “IL-17” domains, and the nine IL-17 receptor family members contained typical “SEFIR domain” or “IL17_R_N domain”. Syntenic analysis revealed that all IL-17s and IL-17Rs were chromosomally conserved compared with other fish. The phylogenetic analysis further confirmed the evolutionary conservatism of different copies of IL-17C and IL-17Rs. Tissue distribution results showed that IL-17 and IL-17R genes were highly expressed in immune-related tissues. The expression of IL-17C and its receptor in the mucosal immune tissues after infection with V. anguillarum were analyzed subsequently, which were significantly increased in the skin. The results are consistent with previous studies showing that IL-17 and IL-17 receptor play an important role in promoting innate immune response.

Identification and Analysis of Aux/IAA Family in Acer rubrum.

The phytohormone auxin are important in all aspects of plant growth and development. The Auxin/Indole-3-Acetic Acid (Aux/IAA) gene responds to auxin induction as auxin early response gene family. Despite the physiological importance of the Aux/IAA gene, a systematic analysis of the Aux/IAA gene in Acer rubrum has not been reported. This paper describes the characterization of Acer rubrum Aux/IAA genes at the transcriptomic level and Acer yangbiense Aux/IAA genes at the genomic level, with 17 Acer rubrum AUX/IAA genes (ArAux/IAA) and 23 Acer yangbiense Aux/IAA (AyAux/IAA) genes identified. Phylogenetic analysis shows that AyAux/IAA and ArAux/IAA family genes can be subdivided into 4 groups and show strong evolutionary conservatism. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to test the expression profile of ArAux/IAA genes in different tissues under indole-3-acetic acid (IAA) treatment. Most ArAux/IAA genes are responsive to exogenous auxin and have tissue-specific expression. Overall, these results will provide molecular-level insights into auxin metabolism, transport, and signaling in Acer species.

Взаимосвязь инкрементов продолжительности жизни и массы тела Drosophila melanogaster с дифференциаль-ной экспрессией генов циркадных ритмов в условиях культивирования с повышенным содержанием белка

The rhythmic functioning of the molecular circadian clock in various tissues and nutrition has a significant impact on the duration and quality of life, as well as the rate of aging of organisms. It is known that body weight correlates with the expression of various genes and the risk of death at different ages. In this study, an attempt was made to identify patterns in realization of genetic information under the influence of various factors, in particular, the ability of ectopic expression of circadian rhythm genes in the fat body and muscles to influence body weight in conditions when media contain different concentrations of protein. We used transgenic Drosophila melanogaster lines carrying UAS sequences in promoters of circadian rhythm genes (cry, per, tim, clk, cyc), that enhance expression, and lines that allow to induce the expression of tissue-specific GSG-311-2 (muscles) and P {Switch1} 106 (fat body). Drosophila body mass was measured on “Mettler Toledo” analytical scales, and a correlation with lifespan increments in response to overexpression of circadian rhythm genes from pre-viously published data was established. A strong correlation was found between the increments of body weight and lifespan in the case of overexpression of circadian rhythm genes in the fat body against the background of a protein-rich diet; according to Spearman, the corre-lation coefficient was 0.955. Based on the results obtained and data on the high evolutionary conservatism of the signaling pathways involved in the process (human signaling pathways are evolutionarily close to Drosophila cascades), generalizations were made regarding the negative consequences of using high-protein diets to reduce the body weight against the background of circadian rhythm disorders that are widespread in megacities.

The Origin of the Okunev Population, Southern Siberia: The Evidence of Physical Anthropology and Genetics

Okunev cemeteries in the Minusinsk Basin were compared with 23 other pre-Andronovo series from southern Siberia, and 45 Early and Middle Bronze Age groups from Eastern Europe (24 Yamnaya and 21 Catacomb), using multivariate statistical analysis. While the Afanasyevo admixture in the Okunev population is possible, the hypothesis that the Okunev culture of the Minusinsk Basin originated from the second migration from the Eastern European steppes to southern Siberia in the Early Bronze Age is not supported. It could, however, be applied to people associated with the Okunev-type (Chaa-Khol) culture in Tuva, although these may as well have descended from the Afanasyevans. As concerns the Minusinsk Basin and other regions of southern Siberia except Tuva, the fi ndings agree with the idea of a marked evolutionary conservatism peculiar to the autochthonous populations of that territory, as evidenced by the fact that each of the three Early Bronze Age population clusters—on the Yenisei, in the Altai, and in Baraba—has its own Neolithic ancestors in the same area (this does not concern the Chaa-Khol, the Yelunino, and apparently the Samus populations). The immediate ancestors of the Okunev people can be identifi ed with the Neolithic population of the Krasnoyarsk-Kansk area, and more distant ones with the Upper Paleolithic southern Siberian common ancestors of the Okunev people and the Native Americans. These ancestors are evidenced by both cranial data (indirectly) and genetic data (directly). The la tter suggest that among these common ancestors were the Malta boy and the Afontova Gora II male. The Okunev population, then, is a relic, offering us a unique opportunity to see what the Upper Paleolithic ancestors of the Native Americans may have looked like in their southern Siberian homeland.

Microorganization of ovaries and oogenesis of Haplotaxis sp. (Clitellata: Haplotaxidae).

Ovaries of Haplotaxis sp. were studied in active and nonactive states, that is, in a sexually mature specimen and in specimens outside of the reproductive period. Two pairs of ovaries were found in segments XI and XII. Especially in the nonactive state, they were in close contact with copulatory glands. Each ovary was composed of germ cells interconnected with syncytial cysts, which were enveloped by a layer of somatic cells. Within cysts each germ cell had one ring canal connecting it to the common anuclear cytoplasmic mass called a cytophore. During oogenesis clustering germ cells differentiated into nurse cells and oocytes; thus, the oogenesis was recognized as meroistic. Vitellogenic oocytes were detached from the ovaries and continued yolk absorption within the body cavity. Because recent studies have shown the variety of ovaries and germ line cyst organization in clitellates and suggest their evolutionary conservatism at the family or subfamily level, the data presented here can be valid in understanding the phylogenetic relationships among Clitellata. In this context, ovaries found in Haplotaxis sp. resembled those of the "Tubifex" type. "Tubifex" ovaries are characteristic for numerous microdrile taxa (tubificines, limnodriloidines, propappids, lumbriculids, and leech-like branchiobdellids) and can be regarded as the primary character for these Clitellata in which germ-line cysts are formed during early oogenesis. As the family Haplotaxidae is currently considered to be paraphyletic and the species studied here belongs to Haplotaxidae sensu stricto, our results support the close relationship of Haplotaxidae sensu stricto to the clade consisting of Lumbriculidae, Branchiobdellida, and Hirudinida, in which lumbriculids are sister to the latter two.

An ultrastructural study of the ovary cord organization and oogenesis in the amphibian leech Batracobdella algira (Annelida, Clitellata, Hirudinida)

This study reveals the ovary micromorphology and the course of oogenesis in the leech Batracobdella algira (Glossiphoniidae). Using light, fluorescence, and electron microscopies, the paired ovaries were analyzed. At the beginning of the breeding season, the ovaries were small, but as oogenesis progressed, they increased in size significantly, broadened, and elongated. A single convoluted ovary cord was located inside each ovary. The ovary cord was composed of numerous germ cells gathered into syncytial groups, which are called germ-line cysts. During oogenesis, the clustering germ cells differentiated into two functional categories, i.e., nurse cells and oocytes, and therefore, this oogenesis was recognized as being meroistic. As a rule, each clustering germ cell had one connection in the form of a broad cytoplasmic channel (intercellular bridge) that connected it to the cytophore. There was a synchrony in the development of the clustering germ cells in the whole ovary cord. In the immature leeches, the ovary cords contained undifferentiated germ cells exclusively, from which, previtellogenic oocytes and nurse cells differentiated as the breeding season progressed. Only the oocytes grew considerably, gathered nutritive material, and protruded at the ovary cord surface. The vitellogenic oocytes subsequently detached from the cord and filled tightly the ovary sac, while the nurse cells and the cytophore degenerated. Ripe eggs were finally deposited into the cocoons. A comparison of the ovary structure and oogenesis revealed that almost all of the features that are described in the studied species were similar to those that are known from other representatives of Glossiphoniidae, which indicates their evolutionary conservatism within this family.

Improving the thermal stability of Bacillus subtilis lipase based on multiple computational design strategies

Improving the thermal stability of enzymes is a hot and difficult point in the field of biocatalysis. Compared with the traditional directed evolution, computational assisted rational design is more efficient, and is widely used in enzyme engineering. Using Bacillus subtilis LipA as the model protein, the structure cavity of the enzyme was analyzed by Rosetta-VIP design, the mutation which was beneficial to the filling of the structure cavity (ΔΔE<0) was selected, followed by the solvent accessible surface area and evolutionary conservation analysis. The thermal stabilities of six out of sixteen designed single-point mutants were improved, with a maximum ΔTm value of 3.18 °C. These six mutations were further used for iterative combination mutation, the maximum ΔTm of the two-point and three-point combination mutants were 4.04 °C and 5.13 °C, respectively. The Tm of the four-point combination mutant M11 (F17A/L114P/I135V/M137L) was increased by 7.30 °C. The Tm of the six-point combination mutant M10 (F17A/V74I/L114P/I135V/M137A/I157L) was increased by 7.43 °C. The thermal stability of mutation with lower energy value, reduced accessible surface area, while conformed to evolutionary conservatism, was more likely to be improved. Therefore, the multiple virtual screening strategy based on the enzyme structure cavity filling, solvent accessible surface area and amino acid sequence conservation analysis can effectively improve the thermal stability of enzyme.

Comparative analysis of larval growth in Lepidoptera reveals instar‐level constraints

AbstractJuvenile growth trajectories evolve via the interplay of selective pressures on age and size at maturity, and developmental constraints. In insects, the moulting cycle is a major constraint on larval growth trajectories.Surface area to volume ratio of a larva decreases during growth, so renewal of certain surfaces by moulting is likely needed for the maintenance of physiological efficiency. A null hypothesis of isometry, implied by Dyar's Rule, would mean that the relative measures of growth remain constant across moults and instars.We studied ontogenetic changes and allometry in instar‐specific characteristics of larval growth in 30 lepidopteran species in a phylogenetic comparative framework.Relative instar‐specific mass increments (RMI) typically, but not invariably, decreased across instars. Ontogenetic change in RMIs varied among families with little within‐family variation. End‐of‐instar growth deceleration (GD) became stronger with increasing body size across instars. Across‐instar change in GD was conserved across taxa. Ontogenetic allometry was generally non‐isometric in both RMI and GD.Results indicate that detailed studies on multiple species are needed for generalizations concerning growth trajectory evolution. Developmental and physiological mechanisms affecting growth trajectory evolution show different degrees of evolutionary conservatism, which must be incorporated into models of age and size at maturation.

Developing Computational Model to Predict Protein-Protein Interaction Sites Based on the XGBoost Algorithm.

The study of protein-protein interaction is of great biological significance, and the prediction of protein-protein interaction sites can promote the understanding of cell biological activity and will be helpful for drug development. However, uneven distribution between interaction and non-interaction sites is common because only a small number of protein interactions have been confirmed by experimental techniques, which greatly affects the predictive capability of computational methods. In this work, two imbalanced data processing strategies based on XGBoost algorithm were proposed to re-balance the original dataset from inherent relationship between positive and negative samples for the prediction of protein-protein interaction sites. Herein, a feature extraction method was applied to represent the protein interaction sites based on evolutionary conservatism of proteins, and the influence of overlapping regions of positive and negative samples was considered in prediction performance. Our method showed good prediction performance, such as prediction accuracy of 0.807 and MCC of 0.614, on an original dataset with 10,455 surface residues but only 2297 interface residues. Experimental results demonstrated the effectiveness of our XGBoost-based method.

A role of peptidoglycan recognition proteins in regulating innate immune response

By now, a whole number of pathogenic antibiotic-resistant or tolerant microorganisms has been progressively increased. Hence, efficient fight against them requires to change the class of antibiotics, increase their dose, or develop new antimicrobial drugs. On the contrary, another option could rely on augmenting innate immunity. During coevolution, eukaryotes have developed several ways for their protection against microorganisms. Innate immunity conserved in all multicellular organisms. The essential principles of innate immunity include recognition of a foreign structures and their subsequent destruction. A set of specific receptors recognize conserved pathogen-derived structures. Elimination occurs due to phagocytosis and cleavage, e.g. via oxidative burst in phagocytic cells, compliment system or antimicrobial peptides. Recognition system in innate immunity is based on the pattern recognition receptors. Due to the pathogen diversity, multiple conserved structures typical to pathogens (e.g. lipopolysaccharide, peptidoglycan, flagellin etc.) are sensed by numerous receptors. The family of peptidoglycan recognition proteins is among such receptors, which were first isolated in 1996 from the silkworm Bombyx mori and mice. Later, it was demonstrated that this family is conserved and its members are found in insects, fish and mammals. Here, functions of insect peptidoglycan recognition proteins in Drosophila melanogaster as well as mammals are discussed. Such proteins are expressed mainly in liver cells (insects — in adipose tissue cells as analogue of mammalian liver), intestinal cells, and epidermis. Numerous studies demonstrate that peptidoglycan-recognition proteins moderate immune response, and may act as antimicrobial proteins, or to regulate microbiota as well as prevent enterocyte activation and restrict inflammatory response. Due to evolutionary conservatism observed for such proteins and inability for bacteria to evade their protective effects, it seems promising to use peptidoglycan recognition proteins in a combination therapeutic approach against antibiotic-resistant and antibiotic-tolerant forms of microorganisms.

Evolutionary Diversity of the Mechanisms Providing the Establishment of Left-Right Asymmetry in Metazoans

Left-right asymmetry is an important feature of the body plan of bilaterian animals. Malformations of the left-right axis result in pathologies of varying severity. Therefore, studying the mechanisms of its establishment in embryonic development is important for science and medicine. The main question to answer in the course of research is how and when the symmetry breakage in a developing organism occurs. This area of research is intensely developing, and various mechanisms of the left-right axis establishment have already been discovered in animals of different phylogenetic groups. Unfortunately, comparative studies of these mechanisms often focus on a few phylogenetically distant objects of developmental biology and do not analyze the diversity that exists within the taxonomic groups. Therefore, the aims of this review are to show the diversity of mechanisms for establishing left-right asymmetry in the early development of metazoans, to make assumptions about the evolutionary conservatism of these mechanisms, and to establish which of the mechanisms is primary for the Bilateria and for the Metazoa in general. The article systematizes our knowledge about the establishment of left-right asymmetry on the basis of the Nodal signaling cascade activity, compares the morphology and functioning of the left-right organizers of different animals, and compares the role of mechanical tensions in establishing asymmetry in different Protostomia. Generalization and analysis of data on the establishment of left-right asymmetry provides a new insight into the evolution of the development of metazoans.

Происхождение окуневского населения Южной Сибири по данным физической антропологии и генетики

Для проверки конкурирующих гипотез о происхождении окуневской культуры проведено многомерное статистическое сопоставление четырех мужских краниологических серий из окуневских могильников в Минусинской котловине с 23 другими сериями доандроновского времени из Южной Сибири и 45 сериями раннего и среднего бронзового века из Восточной Европы (24 ямные и 21 катакомбная). Афанасьевская примесь у окуневцев вполне вероятна, однако гипотеза о сложении окуневской культуры Минусинской котловины в результате второй миграции из восточно-европейских степей в Южную Сибирь в эпоху ранней бронзы не подтверждается. Она могла бы быть применима к носителям культуры окуневского типа (чаахольской) в Туве, но эти люди могли быть и потомками афанасьевцев. Результаты анализа серий из Южной Сибири (кроме Тувы) согласуются с мнением о значительной стабильности местного антропологического субстрата. Она проявляется в том, что для каждой из трех групп популяций эпохи ранней бронзы — енисейской, алтайской и барабинской - обнаруживаются неолитические предки на той же территории (к чаахольскому, елунинскому и, вероятно, самусьскому населению это не относится). Непосредственными предками окуневцев следует считать неолитических обитателей красноярско-канского района, более отдаленными — верхнепалеолитических общих предков окуневцев и американских индейцев. О их наличии свидетельствуют данные краниологии (косвенно) и генетики (прямо), причем генетические показывают, что к числу этих предков относились люди со стоянок Мальта и Афонтова Гора II. Реликтовая окуневская группа, таким образом, дает нам уникальную возможность представить себе, как могли выглядеть верхнепалеолитические предки индейцев на своей южно-сибирской прародине.

Identification of membrane protein types via multivariate information fusion with Hilbert–Schmidt Independence Criterion

Membrane proteins perform a variety of functions vital to the survival of organisms, such as oxidoreductase, transferase or hydrolase. If the type of membrane protein can be detected, the function of protein can be quickly determined. Many existing computational methods not only use the autocorrelation function on the hydrophobicity index of amino acids, but also consider the evolutionary conservatism information of the primary protein sequences. In this study, we employ Average Blocks (AvBlock), Discrete Wavelet Transform (DWT), Discrete Cosine Transform (DCT), Histogram of Oriented Gradient (HOG) and Pseudo-PSSM (PsePSSM) to extract evolution characteristics from Position-Specific Score Matrix (PSSM). Then, we construct five kernels from above five corresponding feature sets. Finally, we propose a novel Multiple Kernel Support Vector Machine (MKSVM) classifier based on Hilbert Schmidt Independence Criterion (HSIC) to integrate five kernels for identifying membrane proteins. For the performance evaluation, our method is tested on four benchmark datasets of membrane proteins. The comparative results demonstrate that our prediction model achieves the best performance among all existing outstanding approaches.

Evolution of MIR159/319 genes in Brassica campestris and their function in pollen development.

MIR159/319 have conserved evolution and diversified function after WGT in Brassica campestris, both of them can lead pollen vitality and germination abnormality, Bra-MIR319c also can function in flower development. MiR159 and miR319 are extensively studied highly conserved microRNAs which play roles in vegetative development, reproduction, and hormone regulation. In this study, the effects of whole-genome triplication (WGT) on the evolution of the MIR159/319 family and the functional diversification of the genes were comprehensively investigated in Brassica campestris. We identified 11 MIR159/319 genes in B. campestris, which produced five mature sequences. After analyzing the precursor sequences and phylogenetic tree, we found that Bra-MIR159/319 have evolutionary conservatism. Furthermore, Bra-MIR159/319 show functional diversification after WGT, as indicated by their expression patterns and the cis-element in their promoter. GUS signal showed that Bra-MIR159a and Bra-MIR319c can be expressed in anther but in different development stages. In B. campestris, overexpressed MIR159a and MIR319c contribute to late anther development and promote pollen abortion. Moreover, Bra-MIR319c can partially assume the function of MIR319a in flower development.

Why does allometry evolve so slowly?

Morphological allometry is striking due to its evolutionary conservatism, making it an example of a certain sort of evolutionary stasis. Organisms that vary in size, whether for developmental, environmental, or evolutionary reasons, adopt shapes that are predictable from that size alone. There are two major hypotheses to explain this. It may be that natural selection strongly favors each allometric pattern, or that organisms lack the development and genetic capacity to produce variant shapes for selection to act on. Using a high-throughput system for measuring the size and shape of Drosophila wings, we documented an allometric pattern that has been virtually unchanged for 40 million years. We performed an artificial selection experiment on the static allometric slope within one species. In just 26 generations, we were able to increase the slope from 1.1 to 1.4, and decrease it to 0.8. Once artificial selection was suspended, the slope rapidly evolved back to a value near the initial static slope. This result decisively rules out the hypothesis that allometry is preserved due to a lack of genetic variation, and provides evidence that natural selection acts to maintain allometric relationships. On the other hand, it seems implausible that selection on allometry in the wing alone could be sufficiently strong to maintain static allometries over millions of years. This suggests that a potential explanation for stasis is selection on a potentially large number of pleiotropic effects. This seems likely in the case of allometry, as the sizes of all parts of the body may be altered when the allometric slope of one body part is changed. Unfortunately, hypotheses about pleiotropy have been very difficult to test. We lay out an approach to begin the systematic study of pleiotropic effects using genetic manipulations and high-throughput phenotyping.

Butchering Benevolence Moral Progress beyond the Expanding Circle

Standard evolutionary explanations seem unable to account for inclusivist shifts that expand the circle of moral concern beyond strategically relevant cooperators. Recently, Allen Buchanan and Russell Powell have argued that this shows that that evolutionary conservatism – the view that our inherited psychology imposes significant feasibility constraints on how much inclusivist moral progress can be achieved – is unjustified. Secondly, they hold that inclusivist gains can be sustained, and exclusivist tendencies curbed, under certain favorable socio-economic conditions. I argue that Buchanan and Powell concede too much to the evolutionary conservative, because their second point shows that conservatives are right about the first: inclusivist shifts are unrealistic where it matters most, namely under harsh social, political and economic conditions. I suggest two promising strategies for solving this problem. One is to focus on different forms of moral progress to secure the same moral gains. The other is to look beyond possible extensions of our psychological capacities altogether, by providing institutional support that renders them irrelevant. We should bypass, rather than further stretch, the constraints of our evolved psychology to make moral progress possible.

Evolutionary history of Polyneoptera and its implications for our understanding of early winged insects

Polyneoptera represents one of the major lineages of winged insects, comprising around 40,000 extant species in 10 traditional orders, including grasshoppers, roaches, and stoneflies. Many important aspects of polyneopteran evolution, such as their phylogenetic relationships, changes in their external appearance, their habitat preferences, and social behavior, are unresolved and are a major enigma in entomology. These ambiguities also have direct consequences for our understanding of the evolution of winged insects in general; for example, with respect to the ancestral habitats of adults and juveniles. We addressed these issues with a large-scale phylogenomic analysis and used the reconstructed phylogenetic relationships to trace the evolution of 112 characters associated with the external appearance and the lifestyle of winged insects. Our inferences suggest that the last common ancestors of Polyneoptera and of the winged insects were terrestrial throughout their lives, implying that wings did not evolve in an aquatic environment. The appearance of the first polyneopteran insect was mainly characterized by ancestral traits such as long segmented abdominal appendages and biting mouthparts held below the head capsule. This ancestor lived in association with the ground, which led to various specializations including hardened forewings and unique tarsal attachment structures. However, within Polyneoptera, several groups switched separately to a life on plants. In contrast to a previous hypothesis, we found that social behavior was not part of the polyneopteran ground plan. In other traits, such as the biting mouthparts, Polyneoptera shows a high degree of evolutionary conservatism unique among the major lineages of winged insects.