For decades our attention has been focused on how learning works. However, at the beginning of 2025 it might be more important to shift our focus of learning research on “not learning”. Recent research on learning includes the study of “social learning” of mice (Winiarski et al. 2025) and the related brain mechanisms that are involved in social learning like the prelimbic cortex.
For our human societies we also rely to a great deal on social learning. In mice, however, the disruption of the prelimbic cortex causes mice to no longer seek “social information related to rewards” from other mice. In Eco-HAB cages these mice follow their scent capabilities to “sort” their information seeking from for example higher “social status animals”. This tested reward seeking behavior allows clues to how learning works. The intervention to disrupt the synaptic plasticity in a later phase of the experiment reveals less social learning from the network social information and fewer contributions to the social network.
Only intact neural plasticity in the prelimbic cortex ensures the maintaining of the social structure. Of course it is highly questionable, whether these results based on animal experiments tell us anything about social structure and social learning in other mammals, but there might be reasons to search for explanations of “no social learning” in humans as well. 
Animal Longevity
- From time to time it is interesting to study animals from many species to maybe learn from them about longevity. Roberto Salguero-Gómez (LINK) developed a sociality continuum and compared 152 species across 13 taxonomic classes. The study reiterates and generalizes the many studies of single species and finds that „more social species live longer, have more generation time and longer reproductive windows“. Social structures amongst animals of the same species influence survival and reproduction as basic demographic processes. These processes determine to a large extent the size of animal populations. Sociality appears to be a major contributor to longevity compared across species. These processes determine the survival of rather solitary species like panda bears (running higher risks of extinction) compared to populations of bees with rather hierarchical predefined social structures. The spotted hyenas developed cooperative hunting and communal care which allows for effective survival compared to other species. Sociality is specific to species and therefore largely determined by genetic factors. Nature rather than nurture is at work. However, species where reproduction occurs later allow for learning curves of sociality. In other words even within species there is scope to improve longevity through sociality. Migration patterns or experience with migration might be yet another determinant of survival or longevity as climate change poses new challenges to many species.
Chinny Trait
In evolutionary biology there is still a discussion about the functional explanation of why humanoids developed a chin. A recent paper by Meyer-Rochow adds a new functional explanation for the evolution of the chin to the literature. Across cultures and sufficiently distant populations of humans, similar patterns of the use of the chin have been observed. In comparison to other species under the superfamily “Hominoidea”, our bites are only of minor strength and apes, Orang Utans have not developed a chin quite like us, homo sapiens. Origins of the chin as “weapon” in fighting and broader social selectivity remain hypotheses without sufficient proof of evidence.
In addition to the functional explanations of easier “mastication” or formation of words, chins might serve as an additional part of the body to hold items to the chest. This function, of holding tools or stuff could have been an advantage for our ancestors and became a favoured trait. During the pandemic our chins became a supporting or hindering reason in the struggle to wear masks for extended periods of time (see image below).
Nowadays, we ask ourselves about the social selectivity into becoming a violin player with this important function of the jaw and chin to hold the instrument. A rival hypothesis is, of course, that holding things with our mouth, like needles or screws, in sewing or handicrafts could eventually make the chin disappear. The bipedalism of hominids, freed our hands for other tasks and the evolution of a chin could similarly reinforce the efficient use of our hands.
Novel use cases for the chin, like holding your smartphone while typing on a keyboard or while opening doors, might enhance the chinny trait of hominids.
Over hundred of thousands of years the interaction of the bio->psycho->social (BPS) spheres of life may have interesting traits for us down (or up) the evolutionary line.
(Image: European parliament, Brussels 2020-7-23 address by Ursula von der Leyen in “masked assembly”).
Birds again
There are many ways to have more birds again in inner cities. Less pollution and poison are part of the solution. Second, increase the food available to birds. Some plants or vegetation is more suited than the other one. Combined with the question of cooling houses in summer and more isolation in autumn and winter, the greening of facades in cities has a simple effect to provide hiding, nesting and feeding spaces for birds. Birds will discover this vegetation as their natural habitat offering relatively safe shelter and food. It is an incredibly simple way to catch 22. Your new shelter is selective in the choice of birds that it will house. Singing birds seem to value the places most. Other predators may follow. At least in late autumn and early winter the energy rich power food is a welcome addition of the diet. Nesting in spring and summer might be another option to have more birds again. We shall need many very small steps again to keep biodiversity or bring back some of it. Birds again is a small initiative.
On Organics
Organics are the new hype. Organics are everywhere. It is true in organic chemistry, biochemistry or pharmaceutical biochemistry we start from organic compounds as the basis for various forms of classification systems, structures and reaction chains. A search for organics brings you to Organic Farming and to lots of other applications of organic production as well as organic design.
The extended definitions highlight the foundation in biology and chemistry to then include any processes which integrate cyclical reproduction or resources and conservation of biodiversity. Based on the plurality of forms and connectivity of organic compounds this leads to a vast and diversified basis of carbon- and hydrogen-based life on earth. The ensuing complexity (variety of species) has been the basis for mankind to come into being. It is likely to determine also our survival in the long run. Organics is based on open as well as closed forms and therefore has an encompassing nature. Depending on time and space constellations (temporality) evolution has taken one or the other path. We are certainly not at the end of this evolution, although we through the loss of biodiversity we narrow down new potentials in an unprecedented way. Rethinking life on earth from a cell-based perspective of plastics and chloroplasts is a challenge, but it will lead us on towards the “organic turn” in the 21st century. 
Bi-directional Sleep
For most of us bi-directional sleep is a question of sleeping on the left or right side, or on our back or front, head left or right. In immunology bi-directionality of sleep has another meaning. The immune system is linked to sleep in a bi-directional manner. Good sleep enhances the immune response of cells (direction 1) and infected blood cells for example send a signal to the brain to extend sleep. The study by Huynh et al. (2024) in Nature has demonstrated this bi-directional mechanism. It allowed mice who slept well after an imposed heart attack to recover in a better way than those whose sleep got interrupted during the experiment. The most natural response to a heart attack or acute coronary syndrome is more sleep. This is induced by an inflammatory reaction in the brain, which « orders » your body to increase deep sleep. 😴 Sleep is more than just rest, it may be part of healing. ❤️🩹 (people looking at Caspar David Friedrich „Infinite Landscapes“, exhibition Alte Nationalgalerie Berlin 2024)
Happy Biology
At first glance happiness from a biological perspective is easy to understand. Its hormones, stupid, that regulates it all. Only problem, there are many of them that interact and, apparently, a lot depends on the right dosis and duration of exposure or deficiency. Oxytocin deficiency seems to be a corollary of anxiety and lack of pro-social behavior, potentially making people less happy – to put it bluntly. There are other complex interactions between hormones not only in the circadian circle of humans like for cortisol, but also related to differential reactions to stress. Genetics and epigenetics are involved as well stress regulation and early exposition to stress during the life course has longer lasting consequences later on. How much stress is good for you? Climbing Mountains induces physical stress, but most people report lasting happiness referring back to such singular events. Hormones seem to play tricks with us as well.
Some time after the novel “Klara and the Sun“, endocrinologists have documented the positive effect of a robot on oxytocin levels in humans. Improvements to mental health and well-being are apparently easy considering that oxytocin is a driver of feeling happy as well. Maybe we should take our depressors and drivers of oxytocin more seriously to be “biologically” happy.
(Image: Extrait Frans Hals 1660, Catharina Hooft and her nurse. Exhibition Gemäldegalerie Berlin 2024) 
Own Insulin
People who suffer from type 1 diabetes do not produce enough insulin themselves. The World Health organization estimated that „in 2017 there were 9 million people with type 1 diabetes; the majority of them live in high-income countries“ (WHO 2023). The report on successful reprogramming of stem cells of a person to produce insulin again and subsequently transplanting these cells into the same person allowed to produce own insulin again for that same person (Mallapaty, 2024). The hope for millions of people with type 1 diabetes is high that eventually there will be a cure to the disease. Scientists caution that there are no data yet for how long the transplanted own stem cells will produce insulin. Hence, the hope is driving research forward on a promising way forward. The case of type 2 diabetes is very different as additionally the absorption of insulin in the body causes problems. We keep walking and building muscles to facilitate the insulin absorption in the body to guard against the onset of type 2 diabetes. Interaction of diabetes and aging is another topic that needs our attention as rapidly aging societies are at higher risks to face many more people with various forms of diabetes.
Olympic Nature
Nature and its biodiversity can teach us many lessons. This is made very explicit in the small exhibition in the “Jardin des Plantes” in Paris. The treasures of (lost) biodiversity are exposed in the adjacent “Muséum National d’Histoire Naturelle”. In a pleasant environment within Paris you can stroll along rare flowers and trees to pass the posters that demonstrate the astonishing achievements of some species (Les champions of nature). For example ants would surpass us in weightlifting in relationship to own weight. A marathon of 42 km is a very short distance for birds flying across continents with rest. High jump or long jump is rather easy for frogs, but we struggle already to jump a little bit higher than our own body length. Lots of other examples are shown the exhibition and should make us a bit more humble concerning the sport accomplishments of humans. Beyond Darwin and Mendel there is a lot to see and experience in the Great Gallery of Evolution. After the question remains whether we are really at the top of the evolutionary ladder. In terms of marketing our successes irrespective of many species disappearing with rapid speed, we still appear rather unique in the evolution. Learning from other species as in bionics is a powerful strategy which is also quite effective to empower humans compared to other species.
Live longer
It is an old dream of mankind to live longer and longer. The Covid-19 pandemic has taught us many lessons that there are powerfully viruses and their continued mutations which threaten this. Life expectancy declined slightly during the pandemic and we learned that long Covid is yet another threat to our life expectancy. Scientists have found other sources that are crucial for survival. Like sepsis, it is the constant inflammation processes in our bodies. Long working times, stressful commute to work and interrupted or shortened vacations all contribute to keep inflammation at higher levels than is healthy from a longevity perspective. The research note published in Nature on the inflammation enhancing protein IL-11 highlights the chain reaction process of inflammation causing cancer and autoimmune disorders and diseases. Hence, it is essential to watch the biomarkers of inflammation and probably adjust our lifestyles accordingly. The sources of inflammation are manifold, but the potential rewards to address the issue are huge as well. Among the easy to address sources is nutrition, exercise and working life. Changing just a little bit here and there can make already a change. Monitoring how you feel about such changes puts you on a learning curve for your own inflammation levels. Vacation times are also perfect for adaptive behavioral changes. We just need to keep trying.
Fertility BPS-SPB
Fertility is another example of the co-determination of the biological, psychological and societal spheres of life. The latest available data for Germany and Sweden in 2023 show a remarkable decline of 10% in the seasonally adjusted Total Fertility Rate (TFR) in both countries (Bujard, Andersson 2024). The TFR was at 1.3 in Germany and 1.5 in Sweden. This means both countries are well below their population replacement rate. In both countries the populations will shrink further. There are no easy answers to the question: why?
The co-determination of the biological, psychological and societal spheres of life seems to be combined driving force. The biological clocks are ticking for women who delayed birth. Maybe pollution of drinking water or PFAS, nanoparticles of plastics disturb fertility. Psychological reasons such as increased anxieties due to the Covid-19 pandemic, lock downs or closed schools have left parents without adequate support for 2 years. Isolation or loneliness could have delayed partnerships and fertility as a consequence. The social environment has also provided additional uncertainty as the cost of living has risen and affordable housing for families is scarce in both countries.
We have probably underestimated the effects of the “Zeitenwende” on people’s mind sets. Sweden has suddenly sought to join NATO to achieve a broader military safety net for its people. In Germany the experience of damages due to war or as a consequence of Russian occupied territory is very present in people’s mind. The war of Russia in Ukraine may have increased uncertainties, anxieties beyond the immediate effects of higher living costs, interest rates or prices for energy. At best fertility might only be delayed for some years, but the consequences of shrinking populations need to be taken seriously. Making societies more welcoming for children and their parents is part of the solution. 
Sleeping BPS-SPB
Sleeping is a good example of the co-determination of the biological, psychological and societal spheres of life. The environment with the daily cycles of light and dark as well as the social norms of work and rest determine the circadian cycles of hormones. Shift work or otherwise disrupted sleep patterns depend on social norms like regulation of noise or light in cities. Healthy sleep patterns, therefore, depend to a large amount on regulation and implementation of those social norms. Birthday parties are tolerated, but much less the irregular partying in shared housing with lots of neighbours. Reducing social contacts during Covid-19 led to the changes in sleep patterns as well.
The psychological determinants of sleep go well beyond the world of dreams as theorized by Freud. Nowadays, we investigate all sorts of behavioural patterns that have an impact on sleeping like “bedtime technology use” of smartphones or the ability to switch off thinking of problems. Sleeping is a particular functional state of our mind. A lot of sorting of daily impressions into memory occurs during the different phases while sleeping. Persistent disrupted or impeded sleep is recognized as torture in severe cases. Stress at work or working overtime is also a major cause of sleep disorders.
The biological indicators used to investigate sleep have revealed a lot of links of sleep and the hormones of melatonin as well as cortisol. Testing has become more accessible and provides good indicators of how the biological clocks tick within our bodies.
However, we are only at the beginning of the analysis of more complex interactions of the multiple forms of interaction of the bio->psycho->social (BPS) as well as the social->psycho->bio (SPB) co-determination of sleeping. Scientific research is faced with a steep challenge as the direction of causality is not uniform except in very controlled experimental settings. Maybe the arts have coined and popularized a useful term in this respect. “I am in a New York state of mind”.
(Image: extrait of Magritte. La clairvoyance, 1936 and The cultural context of aging, Jay Sokolovsky) 
Sleep biology
Biological processes work hard during our sleep. Our immune system in particular benefits a great deal from undisturbed sleep. This is the simplest summary of the study by Kabrita et al. (2024).
We can study the temporal expression pattern of major histocompatibility complex MHC class I for example in mice. 2 groups of sleep-restricted versus normal mice reveal the biological impact of sleep restriction. In comparison to the control group sleep restriction in mice produced a bimodal pattern of Splenocytes with higher protein levels during the resting period. Such an increased protein expression during resting periods indicates a “preparedness for a potential infection”. Sleep recovery, even if short compared to the longer sleep restriction, allows to return to the baseline of protein levels. The good message is that at least mice seem to recover rather quickly from sleep deprivation with their immune response system.
The biology of repeated phases of longer sleep deprivation could inform us on the implications of sleep deprivation on aging processes. The biological responses in single event sleep deprivation seem to show a fast recovery pattern. Probably it is worth studying the same recovery process of groups of young versus aged mice.
Anecdotal evidence from myself indicates that recovery after sleep deprivation in older humans is no longer as fast as at younger ages. Behavioural responses might be less sleep deprivation (less fun) or longer recovery periods (stay in bed longer). The behavioural response of humans appears to be an obvious one. Instead of either or, we tend to go for both at the same time.
(AI Image: BING +Dall-E. one group of mice is partying in a club at night. Another group of mice is sleeping tight in another room. Cartoon-like images. 2024-3-18) 
Wissensdialog
Universitäten und Forschungsinstitute leben weitgehend von öffentlichen Geldern. Das bringt eine Verpflichtung mit sich, das Wissen auch einer breiteren Öffentlichkeit zugänglich zu machen. Das Zeiss Großplanetarium in Berlin ist ein Ort, der diese Aufgabe in den Gründungsstatuten trägt. In Kooperation mit beispielsweise dem Campus Berlin-Buch mit seinen vielfältigen Forschungsinstituten werden in einer Vortragsreihe wichtige Erkenntnisse für eine breite Öffentlichkeit vorgestellt. Nur so kann die politische Zustimmung und ethische Abwägung gewährleistet werden, warum Tierversuche (meistens an Mäusen) in einigen Bereichen schwer verzichtbar sind. Damit wir den Alterungsprozess auch beim Menschen besser verstehen, braucht es immer feinere Darstellungsweisen wo und wie sich Eiweiße an den unterschiedlichsten Stellen im Körper anlagern. Bei Alzheimer finden wir die Ablagerungen in bestimmten Arealen im Gehirn. Dr. Johannes Broichhagen hat im Auftakt zu der Reihe „Neue Wege in der Biomedizin“ Arbeiten aus seinem Labor vorgestellt. Wenn wir Alzheimer eindämmen wollen, müssen wir den Proteintransport im Körper besser verstehen und abbilden können. Das verlangt verbesserte Methoden, um die Proteine darstellen zu können. Die Ablagerung im Gehirn kann vielleicht nicht komplett verhindert werden, aber eventuell hilft bereits eine „Umlenkung“ der schädlichen Proteine. Dazu müssen wir die Transportwege besser verstehen. Wir brauchen dazu 4D Beobachtungen, anstelle der bekannten 2D- oder 3D-Bilder von Gehirnscans. Die Fortschritte sind rasant. Der Wissensdialog nimmt uns mit auf die Wissenschaftsreise. Ein Motivation für viele Jugendliche und Studierende ergab sich aus der anschließenden Diskussion mit beeindruckendem biologischem und chemischem Wissen der Fragenden. So gelingt Wissensdialog für alle Beteiligte. (Image Clip from preprint) 
Garten
Ach es ist so schön im Garten. Ein schöner Garten will geplant werden. Das gelingt auf besondere Weise mit dem „Pollinator“. Hinter dem Pollinator verbirgt sich ein Kunstprojekt, das viele kleine Gartenkunstwerke zu einem großen verbinden möchte. Spannend ist nicht nur das Vernetzungsprojekt von vielen einzelnen Parzellen zu einem größer werdenden Gesamtprojekt (Aggregation), sondern der für Kunstschaffende gewohnte Perspektivwechsel. Aus Sicht der Bestäuber der Pflanzen und Blumen gesehen ergibt sich eine vogelähnliche Perspektive auf den Garten.
Der Parcour einer Biene oder eines Schmetterlings durch unsere Gartenparzelle regt zum Träumen an. Vielleicht hätte Franz Kafka nach der Parcour-Erfahrung ein anderes Insekt gewählt. Mir gefällt die 2D, 3D, 4D Perspektive, die es erlaubt, den blühenden Garten im Zeitraffer durch alle Jahreszeiten zu visualisieren. Das ist Gartenarbeit ohne die mühsame Kleinarbeit des Pflanzens und Unkrautjätens. Es wird nicht gleich ein Garten wie von Impressionisten in Argenteuil von Monet oder in Yerres von Caillebotte daraus, aber ein farbenprächtiges Kleinod allemal. Mein erster virtueller Versuch (Link) ist schon recht farbenfroh. Lateinische Namen auffrischen ist schon fast ein Beitrag zum gesunden Altern, besonders wenn der Garten einige Kilometer entfernt ist. Im Sommer lassen sich leicht neue Pläne schmieden. Herbst und Winter, Trockenheit und Hitze lassen uns das Gartenkunstwerk nochmals überdenken. Spielerisch ein Gartendesign gestalten, kann der erste Schritt für mehr Natur sein. Biodiversität macht Spaß und hilft uns allen. Kleinvieh macht eben auch Mist. 
Birds
The study published in PNAS in May 2023 is demonstrating the loss in bio-diversity with respect to birds over last few decades. Our economic growth has caused considerable costs. Some of these costs we shall never be able to make up again. Species gone for ever, we should care. Measuring the loss is a first step in calculating the negative impact our economic growth models have already caused. Time to stop, repair and reverse as much as we still can. It is not fair to next generations to destroy a large amount of bio-diversity now and leave the exploited planet to “no-future generations”. A good documentation of the losses (radio-france-LINK) allows us to pin down who is most responsible for the losses. Agro-industry with the heavy use of pesticides is well known for the huge negative impact it has on bird populations and us as well. It is not only a European issue, but rather a world-wide issue. However, starting at home is a huge step to practice agriculture differently. Most of this is known for some time. It is the implementation of the necessary policies where powerful lobbying is successful to carry on as usual. Thinking “Beyond growth” delivers many useful perspectives and solutions to these problems. 
Biotop
Die Sensationspresse, zu der leider mehr und mehr ehemals seriöse Zeitungen neigen, zitiert Biotope meistens als Wirtschaftsbremse, Wachstumsverhinderung oder Spaßbremse. Da fällt es schwer dagegenzuhalten. Biodiversität ist nicht umsonst zu haben. Viele Schmetterlingsarten leben bestens angepasst an ihr ökologisches Umfeld, vergleichbar einem Biotop. Farbenpracht dient zur Tarnung im Gelände oder zum Anlocken von Paarungspartnern. Im Botanischen Garten in Berlin werden solche Inseln der Glückseligen für viele Regionen Europas und darüber hinaus nachgestellt. Der frühe Schmetterling von Ende April ist kaum zu bemerken, so gut passt seine Farbkonstellation in sein Umfeld. Es werden richtige Suchbilder und Geduldsproben, die Falter zu entdecken (bitte unten testen). Belohnung lockt für die Geduldigen, wenn das auch vielen von uns unerträglich schwerfällt. Zu schnell sind die Umgebungen für vermeintliche, kurzfristige, wirtschaftliche Interessen zerstört und die angepasste Tierwelt ebenso. Das Bundesnaturschutzgesetz (BNatSchG) intentiert einen Schutz. Der ist aber wohl allzu leicht auszuhebeln. So wird die Farbenpracht und das Tanzen der Schmetterlinge zunehmend in Konzertsälen zu hören oder darüber zu lesen sein, aber seltener in Biotopen zu bewundern sein. Artenvielfalt als Biodiversität braucht die passenden Räume dazu. Eine große Aufgabe bei dem weiteren Anwachsen unserer Spezies.
“Balance” als Geheimnis des Alterns
Die am 13.1.2020 im PNAS veröffentlichte Studie zu Alternsprozessen des Ginkgobaums, der mehr als 1000 Jahre alt werden kann, lassen eine alte Weisheit des Alterns wieder aufleben. Die Balance bestehend aus neuem Wachstum von Zellen und dem Absterben von Zellen beschreibt den Alterungsprozess bei Langlebigkeit. Am Beispiel des langlebigen Ginkgo biloba beschreiben die Autoren den biologischen und genetisch-bedingten Alterungsprozess. Die deutsche Wikipedia-Seite weist interessante Abweichungen zu der englischsprachigen Seite auf. Neben mehr Hinweisen auf potentielle Effekte bei verschiedenen medizinischen Indikationen kann natürlich ein Hinweis auf Goethe nicht fehlen. Hatte er doch den Baum bereits literarisch verewigt in seinem Gedicht von 1815 “Ginkgo biloba”. Kein Wunder also, dass er Ginkgobaum in Deutschland nahezu mythische Kraft zu besitzen scheint. Vereinzelt finden sich Fanseiten des Ginkgo im Internet. Spannend ist jedoch auch der japanische Mythos um den Ginkgo. Selbst die Atombombe von 1945 hatte ein Haus zerstört, doch der benachbarte Ginko blieb erhalten und ist heute ein Denkmal der Hoffnung. Hier schließt sich der Kreis zur Alternsforschung. Wie beeinflussen soziale Kontexte, im Extremfall Kriege, die Genetik und Epigenetik? Wir bleiben dran an dem Thema.
Photo copyright: Jean-Pierre Chéreau & Roger Culos
Ginkgo Biloba, 1815 Gedicht von Johann Wolfgang von Goethe (1749-1832)
- Ginkgo Biloba
- Dieses Baums Blatt, der von Osten
Meinem Garten anvertraut,
Giebt geheimen Sinn zu kosten,
Wie’s den Wissenden erbaut,
- Ist es Ein lebendig Wesen,
Das sich in sich selbst getrennt?
Sind es zwey, die sich erlesen,
Daß man sie als Eines kennt?
- Solche Frage zu erwiedern,
Fand ich wohl den rechten Sinn,
Fühlst du nicht an meinen Liedern,
Daß ich Eins und doppelt bin?
