Homo militaris – Sotaisan ihmislajin synty

Ukrainan sota on palauttanut monien mieleen sodan karut kasvot. Sotatutkimuksen ajatellaan usein kuuluvan yksinomaan yhteiskuntatieteisiin, mutta sodan syitä pohdittaessa ei voida välttyä ajattelemasta sodan merkitystä ihmislajin evoluutiossa. Onko ihmislaji luonnostaan sotaisa vai rauhanomainen

The Finnish matriculation examination in biology from 1921 to 1969 – trends in knowledge content and educational form

The history and evolution of science assessment remains poorly known, especially in the context of the exam question contents. Here we analyze the Finnish matriculation examination in biology from the 1920s to 1960s to understand how the exam has evolved in both its knowledge content and educational form. Each question was classified according to its topic in biology, and its cognitive level by Bloom’s taxonomy. Overall, the exam progressed from a rather dichotomous test of botany and zoology to a modern exam covering biology from biochemistry to environmental science, reflecting the development of biology as a scientific discipline. The contribution of genetics increased steadily, while ecology witnessed a decline and a renaissance during the same time period. The biological profile of the questions was established by the 1950s. The educational standard and cognitive demand of the questions was always high and established by the 1940s.Peer reviewe

Merisiilien tukiranka

Merellinen ja eksoottinen piikkinahkaisten pääjakso jää monelle suomalaiselle biologille varsin tuntemattomaksi lajiryhmäksi. Piikkinahkaisiin kuuluvat merisiilit, merimakkarat, meritähdet, käärmetähdet ja merililjat. Hyönteisiä lukuun ottamatta monilta selkärangattomien taksoneilta ja näiden rakenteilta puuttuu suomenkielinen termistö, johon havahduin tutkiessani merisiilien kehitysbiologiaa ja regeneraatiota Yhdysvalloissa kesällä 2019. Selkärangattomien opetus, tiedotus, kansanvalistus ja innoitus edellyttävät termistöä. Tarkastelen tässä merisiilien tukirangan morfologiaa ja esitän ehdotuksia piikkinahkaisten suomenkieliselle termistölle

Postembryonal utveckling hos Exopterygota : postembryonal morfologi, vingarnas utveckling, extremiternas regeneration, allometri och tillväxtmodeller hos fältsyrsan Gryllys bimaculatus

In recent years, the two-spotted field cricket Gryllus bimaculatus has emerged as a central model for studies on insect development, regeneration and physiology. At the moment, G.bimaculatus has the most extensive molecular toolkit within the Exopterygota, making it the foremost model for evolutionary developmental biology and comparative physiology within the field of entomology. However, the postembryonic development of G. bimaculatus has received considerably less attention than embryonic development. In this thesis, I have studied the postembryonic development of G. bimaculatus to better understand the evolution and physiology of the understudied Exopterygota. My thesis encompasses five parts: postembryonic morphology, wing development, appendage regeneration, allometry, and growth. The postembryonic stages, the nymphal stages, have never been properly characterised in G. bimaculatus. By following postembryonic development daily at 30 C, 8 nymphal stages (instars) were identified. Size, coloration, sclerotisation of the thorax, and morphology of the wings, the hind tibia and the ovipositor were useful characters in distinguishing the stages. The Dpp/BMP signalling pathway patterns the wing venation in the endopterygotan insects Drosophila melanogaster and Athaliae rosae, but nothing is virtually known about wing development in exopterygotan insects. The wings and the wing venation pattern in different nymphal stages of G. bimaculatus were studied using the hydrogen peroxide clearing protocol along with both brightfield and fluorescence microscopy, while the role of the Dpp/BMP signalling pathway was studied using immunohistochemistry (IHC), in situ hybridisation (ISH), and RNA interference (RNAi). The longitudinal veins are patterned in the 3rd and 4th nymphal stages, while the secondary veins in the 8th stage. The IHC and ISH experiments displayed only non-specific staining, while the RNAi experiments did not produce any change in the phenotype, possibly because of molecular redundancy. The nymphal legs of G. bimaculatus are known to be highly regenerative, and the Dpp/BMP signalling pathway has been shown to provide positional information in leg regeneration. However, nothing is known about the regeneration of the other appendages in G. bimaculatus. Antennae and cerci were amputated in different nymphal stages, and the degree of final regeneration depended on the nymphal stage. RNAi experiments did not produce any change in the phenotype, possibly because of molecular redundancy. The interrelationship between static, ontogenetic and evolutionary allometry in insects is poorly understood. The allometry of hind femur length with respect to body length has been shown to be negative in Orthoptera (i.e. evolutionary allometry), but nothing is known about corresponding ontogenetic and static allometry. By measuring hind femur length and body length in G. bimaculatus in different nymphal stages, the ontogenetic allometry was determined to be slightly positive or isometric, while the static allometries of different stages tended to be negative but highly variable. This may indicate that allometric relationships constrain development in the microevolutionary perspective, but are nevertheless evolvable in a macroevolutionary perspective of millions of years. The growth conditions and rearing of crickets and other insects have been widely reported, but the shape of the growth curve itself has been less investigated. The exponential, the von Bertalanffy (VBGF), the West, Brown and Enquist (WBE), and the dynamic energy budget (DBE) models have been proposed as continuous models for insect growth. These models were t to growth data from G. bimaculatus and the DBE and was shown to be optimal with parameter values α=0 and pAm = 0.69. The insects have been thought to follow Dyar's law, i.e. that the growth ratio or moulting increment (MI) is constant throughout development, although numerous other competing moulting models have been devised for the crustaceans. By fitting different moulting models to head width data from G. bimaculatus, the log-linear model (Mauchline's model) turned out to explain the MI the best. Lastly, the oxygen-dependent induction of moulting (ODIM) model has been proposed to explain moulting patterns in insects, but the model has never been applied to exopterygotan taxa. By fitting the ODIM model to growth data from G. bimaculatus, the model could predict moulting mass but not instar durations, probably because of high postembryonic plasticity in G. bimaculatus

Sellanen ol'Viipurin luonnontieteellinen museo

Keskiajalla perustettu Viipuri kuului Ruotsille (1293–1721), Venäjän keisarikunnalle osana Vanhaa Suomea (1721–1812) ja autonomista Suomen suuriruhtinaskuntaa (1812–1917) ennen kuin siitä tuli osa vasta itsenäistynyttä Suomea (1917–1944). Karjalaisten kaupungin merkitys uuden kansallisvaltion kulttuurielämälle ja orastavalle kansallistunteelle on ollut merkittävä, ja Viipurin kaupunki- ja kulttuurihistoria onkin innoittanut monia muistelmia ja katsauksia. Harvat ovat kuitenkin kuulleet Viipurin luonnontieteellisestä museosta ja sen vastuuseurasta Karjalan Luonnon Ystävistä. Museon ja yhdistyksen jännittäviä vaiheita värittävät alullepanijan äkillinen tapaturma, eläintarhan boikotointi, lehtorin murha ja eläintieteellinen näyttely Alvar Aallon suunnittelemassa uudessa kaupunginkirjastossa. Mitä kaikkia tarinoita arkistojen uumenista löytyy

Identification of putative enhancer-like elements predicts regulatory networks active in planarian adult stem cells

Planarians have become an established model system to study regeneration and stem cells, but the regulatory elements in the genome remain almost entirely undescribed. Here, by integrating epigenetic and expression data we use multiple sources of evidence to predict enhancer elements active in the adult stem cell populations that drive regeneration. We have used ChIP-seq data to identify genomic regions with histone modifications consistent with enhancer activity, and ATAC-seq data to identify accessible chromatin. Overlapping these signals allowed for the identification of a set of high-confidence candidate enhancers predicted to be active in planarian adult stem cells. These enhancers are enriched for predicted transcription factor (TF) binding sites for TFs and TF families expressed in planarian adult stem cells. Footprinting analyses provided further evidence that these potential TF binding sites are likely to be occupied in adult stem cells. We integrated these analyses to build testable hypotheses for the regulatory function of TFs in stem cells, both with respect to how pluripotency might be regulated, and to how lineage differentiation programs are controlled. We found that our predicted GRNs were independently supported by existing TF RNAi/RNA-seq datasets, providing further evidence that our work predicts active enhancers that regulate adult stem cells and regenerative mechanisms

ACME dissociation: a versatile cell fixation-dissociation method for single-cell transcriptomics

Single-cell sequencing technologies are revolutionizing biology, but they are limited by the need to dissociate live samples. Here, we present ACME (ACetic-MEthanol), a dissociation approach for single-cell transcriptomics that simultaneously fixes cells. ACME-dissociated cells have high RNA integrity, can be cryopreserved multiple times, and are sortable and permeable. As a proof of principle, we provide single-cell transcriptomic data of different species, using both droplet-based and combinatorial barcoding single-cell methods. ACME uses affordable reagents, can be done in most laboratories and even in the field, and thus will accelerate our knowledge of cell types across the tree of life.This work was supported by an MRC grant (MR/S007849/1) and a Royal Society Grant (RGS\R1\191278) to JS. HG-C was supported by a Nigel Groome studentship from Oxford Brookes University. PA-C was supported by an EMBO Long Term Fellowship (ALTF-217-2018). JN was supported by funding from a BBSRC grant (BB/M011224/1) and the Osk. Huttunen Foundation (Doctoral grant