Human night owls are more likely to retire early and with disabilities. Really!

This might be dubious research! I suspect other factors than the circadian cycle or chronotype.

Again Finnish people were used for this study. See also my other blog post of today involving Finnish subjects. For some reason (better data?), Finnish people seem to be preferred test subjects. 😊

"... People with evening chronotypes are 1.7 times as likely as morning chronotypes to retire early and receive a disability pension, according to research ...

To strengthen the evidence, researchers analyzed whether people classified as E-types in their mid-40s were more likely to receive a disability pension over the next 12 years than people classified as M-types.

The researchers analyzed data from an ongoing population study that began in 1966 and included 96% of all people born in two northern provinces of Finland. ...

During the 12-year follow-up, 135 of the men (5.2%) and 249 of the women (8.1%) were granted their first disability pension.

Being classified as an E-type at age 46 was linked to a 1.7-fold greater likelihood of receiving a disability pension over the following 12 years compared with being an M-type, for both men and women. ..."

From the abstract:

"Objectives

Evening chronotypes (E) generally have poorer health than morning chronotypes (M), but whether this translates into disability pensions (DPs) is poorly known. We examined whether chronotype at age 46 predicts incident DPs over a 12-year follow-up.

Methods

In 2012, we determined chronotype among the non-retired participants of the Northern Finland Birth Cohort 1966 (n=5679) using the short Morningness–Eveningness Questionnaire, further validated by comparing the participants’ survey scores at age 46 with their polygenic scores for morningness (PGSmorn) at age 31 (n=5130). We used Cox regression to calculate HRs with 95% CIs of incident DPs until age 57 (years 2012–2023), adjusting for factors related to socioeconomic status, health, sleep and working times at age 46.

Results

In total, 253 men (9.7%) and 381 women (12.4%) were E-types. The PGSmorn correlated with the chronotype (p<0.001).

During follow-up, 135 men (5.2%) and 249 women (8.1%) were granted their first DP. For E-types, the corresponding proportions were 8.3% and 12.1%, respectively. Compared with M-types, the unadjusted HRs (95% CIs) for DPs among E-types were 1.72 (1.04 to 2.83) in men and 1.73 (1.22 to 2.46) in women. Adjusting for socioeconomic factors did not attenuate the results.

Conclusions

The higher incidence of DPs among E-types in the core productive years of work careers represents a major challenge for sustainable national economies. Further research and action to support health and work ability among E-types are needed."

Night owls may struggle to continue working until official retirement age

Evening chronotype and disability pensions: 12-year register-based follow-up of middle-aged adults from the Northern Finland birth cohort 1966 Free (open access)

When humans were hunted as prey

Recommendable!

When humans were hunted as prey "Bones with leopard bites show humans didn’t always top the food chain"

Can you slow the aging process? Study reveals which interventions might help

Good news! Again, lifestyle improvements (healthier diet, less stress, more physical exercise and so on) are confirmed to be very strong when it comes to healthy aging and long life. The way one ages is to a large extent a personal choice.

Notice this study is focused on epigenetic aging, which may or may not be a narrow focus of the complex process of aging.

"... Using a new class of DNA-based blood tests, they found that lifestyle interventions and certain drug treatments indeed appear to slow the aging process, while over-the-counter supplements don’t have much effect. ...

For their analysis, the researchers primarily used a type of blood-based biomarker known as epigenetic clocks, which estimate epigenetic or biological age by measuring the pattern of methyl groups (basic chemical structures that act like tags) attached to a person’s DNA.

As people age, these chemical tags change, previous research has shown. Successful anti-aging interventions can reverse the tags. Computer algorithms are then able to use the changes observed in these tags to estimate a person’s epigenetic “age.” ...

The researchers tested four categories of intervention: pharmacological drugs, lifestyle-based changes, over-the-counter supplements, and medical procedures. They found that lifestyle interventions, such as a combination of a healthy diet (whether it’s Mediterranean, low-carb, or low-fat) and exercise, consistently decreased epigenetic age.

Pharmacologic interventions — including metformin and semaglutide, prescription medications used for metabolic control and weight management, and anti-TNF therapies, which use biologic medications to target an immune system protein that triggers harmful inflammation — decreased epigenetic age the most. (TNF, or tumor necrosis factor, is an immune-system protein that helps fight inflammation-related injury.) ..."

From the abstract:

"Aging biomarkers can potentially allow researchers to rapidly monitor the impact of an aging intervention without the need for decade-spanning trials.

However, before the use of aging biomarkers, such as epigenetic clocks, as surrogate endpoints, their responsiveness to interventions that target aging must be tested.

Here we curate TranslAGE, a harmonized database of 51 public and private longitudinal interventional studies, and calculate a consistent set of 16 prominent epigenetic clocks for each study, along with 94 other DNA methylation (DNAm) biomarkers that can help explain the changes observed for each clock.

Using this database, we discover patterns of responsiveness across a variety of interventions and DNAm biomarkers.

For example, clocks trained to predict mortality or pace of aging show the strongest responses across all interventions and show consistent results with one another; 

pharmacological and lifestyle interventions drive the strongest responses from DNAm biomarkers; and the characteristics of the study population and study duration are key factors in determining the responsiveness of DNAm biomarkers to an intervention.

Moreover, clocks with multiple subscores (that is ‘explainable clocks’) provide specificity and greater mechanistic insight into the responsiveness of interventions than single-score clocks.

These findings can help to design future clinical trials by guiding the choice of interventions and of specific subsets of DNAm biomarkers to minimize multiple testing, study duration, study population and sample size, with the eventual aim of uncovering DNAm biomarkers that can be used as surrogate aging endpoints."

Can you slow the aging process? Study reveals which interventions might help | Yale News "A new Yale analysis found that diet, exercise, and some medications can slow the aging process, while over-the-counter supplements appear to have little effect."

Responsiveness of epigenetic aging biomarkers to longevity interventions in humans (open access)

Fig. 1: Current paradigms to study the responsiveness of DNAm biomarkers and their limitations.

Fig. 3: Interventions and their effects on 16 prominent DNAm biomarkers.

'Being nude in public can make one feel better about one's bodies

Food for thought! Some societies are more prudish than others. The research cited in the article below is older.

In Germany, e.g. topless in parks or at public swimming pools or nude at some beaches is common. In the US prudishness is common (except for nudity for sale).

For centuries nudity in public was considered uncivilized/primitive or a moral/religious vice in Western societies.

"In the summer of 2020, Berriman bought herself a bikini to wear during a heatwave. She hadn't worn one in 20 years, having struggled with body dysmorphia (a condition where someone fixates on perceived flaws in their appearance) for most of her life. Around a year later, her husband introduced her to naturism.

"Naturism is engaging in social nudity with no expectation, no presence of sexual stimulation," says Kerem Soylemez, assistant professor of psychology at Regent's University London. ...

A quick history of social nudity [this history appears to be very incomplete]

• Some indigenous cultures and tribes have perhaps the longest history of wearing little to no clothing

• In the Western world, athletes often competed in the nude in ancient Greece's Olympics

• In late 19th-Century British India, modern naturism clubs emerged

• In the US, organised naturism traces its origins to 1929 when three German residents of New York met to discuss founding a nudist association in the Micholob Café

• In 1974, the New York Times reported that social nudity was experiencing a wave of popularity in the US

• In the 1920s and '30s, naturism gains popularity in the UK

..."

From the abstract:

"Body image dissatisfaction is a serious, global problem that negatively affects life satisfaction.

Several claims have been made about the possible psychological benefits of naturist activities, but very little empirical research has investigated these benefits or any plausible explanations for them.

In three studies—one large-scale, cross-sectional study (n = 849), and 2 prospective studies (n = 24, n = 100) this research developed and applied knowledge about the possible benefits of naturist activities.

It was found that more participation in naturist activities predicted greater life satisfaction—a relationship that was mediated by more positive body image, and higher self-esteem (Study 1).

Applying these findings, it was found that participation in actual naturist activities led to an increase in life satisfaction, an effect that was also mediated by improvements in body image and self-esteem (Studies 2 and 3).

The potential benefits of naturism are discussed, as well as possible future research, and implications for the use of naturist activities."

'You're fully accepted': Being nude in public can make us feel better about our bodies "Research suggests that naturism, the practice of non-sexual social nudity, can help people improve their body image. Naturists and experts tell the BBC how it works."

Naked and Unashamed: Investigations and Applications of the Effects of Naturist Activities on Body Image, Self-Esteem, and Life Satisfaction (open access, appeared in the Journal of Happiness Studies in 2017)

Fig. 1 Relationship between naturist activity and life satisfaction, mediated by body-image and self-esteem in Study 1. Note *p < .05, **p < .01, ***p < .001

An ancient civilization of 1-3 millions once flourished in the Amazonia

Amazing stuff!

"The first hint that sprawling ancient populations once occupied the Amazon rainforest in Brazil was found through the most mundane of happenstances. More than 20 years ago, geographer Alceu Ranzi, now at the University of Acre, sat on the right side of a plane flying over the ocean of green. Looking down, he saw a perfect circle inscribed on the ground, an unnatural shape produced only, he felt certain, by humans. He was right.

Decades of subsequent research ... have slowly revealed remnants of peoples that occupied even the forest’s most remote areas. ... what archaeologists call earthworks—a type of architecture carved into the landscape. Now, using a laser-based form of radar known as lidar, researchers suggest ancient Amazonians were widespread in territories previously considered uninhabited. ...

The area surveyed by the researchers cuts through Acre and Amazonas, two northern Brazilian states that border Venezuela, Colombia, Peru, and Bolivia. Although scientists already knew there were earthworks in the region, the new study delineated the western and northern borders of the geoglyph-building society, which researchers had previously named Aquiry. Far away from any major rivers, which historically sustained thriving populations, the scientists did not expect the Aquiry to reach such high numbers. ...

The team identified most of the earthworks in the new study as geoglyphs, ditches made in the ground that form geometric shapes including squares and circles, as well as more complex shapes such as pentagrams and octagons. Some are even more sophisticated, combining, for example, circles inside a perfect square. ..."

From the abstract:

"Numerous geometric earthworks have been found in southwestern Amazonia, evidence of a monument-building precolonial civilization. This knowledge has contributed to the discussion about the deep history and the precolonial urbanism of Amazonia, its sociocultural contexts and its environmental legacy.

Estimates of the geographical extent and population size of the forest civilization have remained weak, because the detection of earthworks has been almost exclusively limited to deforested areas where vegetation does not completely hide the structures.

Here we used canopy-penetrating LiDAR data over 4,430 km of flight to define the geographical distribution and quantity of earthworks in this region better. On the basis of both existing data and our LiDAR documentation, we show that this cultural area alone contains as many earthworks as previously estimated for the whole of Amazonia.

We also propose that the total human population of the area in 100–300 ad was 1.25–3 million people.

If similar results are found elsewhere in Amazonia, the total precolonial population density and its effect on the current Amazonian soil and forest structure, biodiversity and even some modelling of the global climate should be re-evaluated."

An ancient civilization of millions once flourished in the Amazon

Odd shapes hidden in dense Amazon rainforest reveal sprawling ancient civilization "Newly found earthworks suggest about 3 million people might have lived in just about 3% of the forest’s entire area"

Over 20,000 precolonial earthworks in the Southwest Amazonia (open access)

An aerial shot shows a square-shaped geoglyph in Acre, a state at Brazil’s northern border

Lidar uses infrared light to uncover the shapes hidden underneath dense tree canopies.

Fig. 2: Diverse earthwork types with their topographical contexts.

Fig. 1: Map of the study area.

Language diversity: A historical context for language loss for the past 6,000 years or more

Over human history, many languages have disappeared and continue to disappear!

Why should the evolution of human languages be so different than the biological evolution? Do we need about 7,000 existing and actively spoken languages on our planet?

Hopefully, the Tower of Babel will go away in the 21st century. The world would be a much better place if we all speak the same language (with or without machine translation)!

Is this article another way of trying to indoctrinate with the DEI (Diversity, Equity, and Inclusion) ideology?

The approach taken in this study, i.e. a kind of extrapolation from present-day hunter-gatherers, is certainly questionable if not junk! This assumption is possibly a very strong inductive bias! What if e.g. the first humans spoke only one or a few languages and that for a long time before language diversity emerged maybe with the geographic spread of humans?

Notice that this study does not blame colonialism, but the preceding multinational empire building and expansion for the loss of languages.

"Humanity’s linguistic diversity is in trouble [???]. Roughly half of the 7500 languages signed or spoken today are endangered [???], and at least four go extinct every year. But while preserving the languages that do persist is a top priority, a new study in Science suggests that we are already more than one millennium beyond humanity’s linguistic “golden age.”

Linguists have long debated when the most languages were in use: Some have argued that the total number of languages remained roughly steady from the last ice age until modern-day European colonialism, others suggested that diversity has steadily declined since the dawn of agriculture about 12,000 years ago, and a third camp theorized a high point sometime before large states became established 4000 years ago.

Since writing was not developed until around 6000 years ago, however, understanding dynamics of early language remained challenging.

So, a team of anthropologists applied data on the languages, distributions, and behaviors of present-day hunter-gatherers to estimates of the total human population size and the size and number of individual cultures over the last 12,000 years. This allowed them to create a model of the total number of languages in use at any point since the last ice age ended.

The researchers showed that linguistic diversity rose steadily for around 10,000 years, reaching a “golden age” of tens of thousands of languages around 1000 to 3000 years ago before entering a language loss free-fall that continues to this day. The results reveal that the language crisis is not the result of modern colonialism but rather the culmination of millennia of cultural exchange and homogenization."

"... The golden age was followed by a period of rapid decline in linguistic diversity that coincided with the rise of large states and multinational empires, such as the Roman Empire, the researchers found. The finding challenges a commonly held view that widespread language extinction began later, about 500 years ago, with the onset of European colonial expansion. ..."

"To the Point

• Fewer languages before agriculture: The researchers estimate that between approximately 4,500 and 6,200 languages were spoken at the beginning of the Holocene, around 12,000 years ago - probably fewer than the roughly 7,500 languages spoken and signed today.
• A linguistic “golden age”: As the global human population grew, language diversity also increased. The models suggest that tens of thousands of languages may have existed between 1,000 and 3,000 years ago.
• A deep history of language loss: The decline in linguistic diversity appears to have begun with the expansion of large states and empires, long before modern European colonialism.
• Today’s languages are survivors [???]: The languages spoken today represent a small and historically biased sample of past linguistic diversity [???], with important implications for how researchers explain global patterns in language and culture.

...

They began with ethnographic data from 171 hunter-gatherer and fisher societies whose traditional subsistence and mobility had not been profoundly transformed by contact with food-producing populations. These data allowed the researchers to estimate the likely distribution of ethnolinguistic group sizes near the beginning of the Holocene.

The team then combined these estimates with reconstructions suggesting that the global human population 12,000 years ago was between approximately 4.4 and seven million. Assuming that ethnolinguistic groups at that time generally corresponded to distinct languages, the models produced an early-Holocene estimate centred on roughly 4,500 to 6,200 languages, although broader plausible estimates ranged from around 3,300 to 7,800. ..."

From the editor's summary and abstract:

"Editor’s summary

More than four languages are lost every year, and this rate is predicted to increase. Blasi et al. investigated how language diversity has changed over the Holocene using a Bayesian modeling approach, ethnographic data, and estimates of the total human population size over time.

They assumed a maximum size of ethnolinguistic groups and that the number of different ethnolinguistic groups is related to the number of languages. Their findings suggested that language loss is not a new phenomenon, and that language diversity has been decreasing rapidly over the past one to three millennia following a peak of an order of magnitude higher diversity than we see today. ...

Abstract

Characterizing the factors that have shaped linguistic diversity is fundamental for understanding human history, culture, and cognition.

In this study, we combined statistical and social computational modeling, ethnographic data, and paleodemographic inference to model trajectories of global linguistic diversity.

Before the onset of plant and animal domestication, the number of languages was smaller than it is today (4500 to 6000 compared with 7500).

Subsequent increases in global population precipitated increased linguistic diversity.

We uncovered a linguistic “golden age” with tens of thousands of languages 3000 to 1000 years ago. Great loss of linguistic diversity did not begin with recent colonial expansion but as multinational empires first spread along with their languages, pathogens, and cultures. Thus, extinction has likely played a much greater role in shaping linguistic and cultural diversity than previously thought."

ScienceAdviser

In Science Journals

Study uncovers lost ‘golden age’ of languages (original news release) "A new study coauthored by Yale linguist Claire Bowern suggests that tens of thousands of languages were spoken between 1,000 and 3,000 years ago."

The lost golden age of language diversity (original news release)

The rise and fall of language diversity through the Holocene (no public access)

Map of currently spoken and signed languages of the world, colored by endangerment status.

Ancient Mesoamericans used a-maize-ing strategies to avoid malnutrition

Ama(i)zing stuff!

"Corn flakes for breakfast, tamales for lunch, and some hominy grits with a side of corn bread for dinner? As delicious as this corn-ucopia sounds, such a maize-heavy diet is not without potential health trade-offs: Maize contains very little lysine, an amino acid important for preventing connective tissue disorders and anemia. For the hundreds of millions of people around the world who rely on maize as their primary source of food, finding dietary supplements that can add lysine is vital to prevent malnutrition.

To help understand how the earliest maize-eating societies avoided these consequences, a group of researchers examined the remains of 39 humans who lived in Belize between 1100 and 6100 years ago—just a few millennia after corn was first domesticated in Mexico.

By taking small samples from the skeletal remains and analyzing the ratios of carbon isotopes in their amino acids, the researchers deduced that the people ate animals like turkeys that had themselves eaten corn and concentrated the lysine in their bodies, allowing the amino acid to build up through a process known as trophic magnification. The findings ... suggest that Mesoamericans may have provided maize to food animals long before fully domesticating them around 2200 years ago ..."

From the abstract:

"The adoption of maize as a dietary staple shaped human societies. While a reliable carbohydrate-rich source, its inherent nutritional limitations posed substantial challenges.

Maize is deficient in lysine, an essential amino acid crucial for maintaining balanced health.

Maize-dependent diets, therefore, necessitated complementary dietary strategies. We report amino acid stable carbon isotope data from 39 directly dated humans from southern Belize [6100 to 1100 before present (B.P.)] to investigate how early populations mitigated nutritional deficiencies.

Concentration-dependent mixing model results indicate that protein supplementation from maize-eating animals contributed maize-derived lysine to human diets through trophic magnification (elevated proportions of isotopically distinct nutrients in tissues from trophic transfer).

Our results indicate that such strategies were in place by 6100 B.P., consistent with evidence of early maize cultivation but predating reliance by ~2000 years. Our findings highlight early coevolutionary dynamics linking maize cultivation and human-animal provisioning relationships, deepening understandings of adaptive food systems during agricultural transitions and offering insights into nutritional strategies underpinning sustainable subsistence."

ScienceAdviser

Nutritional Adaptations to Early Maize Cultivation: Earliest Isotopic Evidence of Maize Based Animal Provisioning in the Neotropics Tracing Early Maize-Based Animal Provisioning (original news release)

Nutritional adaptations to early maize cultivation: Earliest isotopic evidence of maize-based animal provisioning in the Neotropics (open access)

Fig. 1. Human and turkey maize and nixtamalized maize daily requirements.

Fig. 6. Analytical framework for calculating dietary contributions of maize-based foods and maize-consuming animals to individual lysine δ13C values.

Did humans evolve from knuckle-walking ancestors?

Knuckle walking for knuckleheads? Just kidding!

"Humans are the only primates that walk upright all the time, an adaptation that has freed up our hands to more nimbly build tools, lug around food, and carry out other dexterous tasks. Hidden in the eight small bones of the wrist is an anatomical hint to where that gift of grab originated.

Now, the most comprehensive analysis of primate wrist bones to date ... concludes that our wrists more closely resemble those of gorillas and chimpanzees than any other primate group, a similarity the authors link to a possible knuckle-walking past.

Scientists have long looked to wrist anatomy for clues to our evolutionary past, comparing our wrists to those of other living primates such as chimps and gorillas (which knuckle-walk) or capuchins and macaques (which flat-palm walk). Studying fossil hominins’ wrists for signs of these adaptations has proven tricky, as the wrist is a complex puzzle of eight or nine interlocking bones. So, researchers digitally reconstructed and quantified the exteriors of 2037 wrist bones across multiple living and extinct species, including monkeys and apes.

For nearly every bone examined, human wrist bones resembled the equivalents in knuckle-walking African apes far more than those of any other primate group. Human wrists also feature traits that help stabilize other primates’ wrists during knuckle walking—a sign of evolution’s opportunism. Features that once steadied the wrist in our distant ancestors laid the foundation for adaptations that yielded our dexterous wrists. ..."

"... The study also finds that bone structures tied to sophisticated tool use emerged surprisingly late in human evolution, within the past few hundred thousand years. ..."

From the abstract:

"Hominin forelimbs have evolved from primarily locomotive to manipulative appendages over approximately 6 million years. As such, hand functions in fossil hominins and the Pan–Homo last common ancestor (LCA) are intensely debated, with carpal morphology central to this debate. However, owing to their irregular and challenging shapes, few studies have comprehensively quantified carpal morphology.

We analyse the overall carpal morphology of anthropoids, including fossil hominins, using spherical harmonics and use classification methods to characterize fossil hominins within the context of extant taxa.

Results show that hominins share with African apes derived carpal morphology possibly related to knuckle walking. Furthermore, unique modern human carpal morphology appears to have evolved from these possible knuckle-walking features and in a piecemeal manner, causing some hominin capitates to resemble those of palmigrade monkeys. Striking variation in biomechanically relevant carpal morphology and retention of potentially ancestral features persists as late as Homo naledi, suggesting that most hominins probably neither knuckle walked nor extensively used stone tools. 

These results indicate that the hominin carpus evolved from an African ape-like wrist, with radial-side reorganization related to manipulation occurring only recently. Although it remains unclear whether the LCA knuckle walked, our results suggest that this is the most likely existing hypothesis."

ScienceAdviser

New study strengthens idea that humans evolved from knuckle-walking ancestors

Did modern human carpal morphology evolve from knuckle walking traits? (open access)

Figure 2. Scatterplots of PC1 and PC2 for all examined carpals. Lunate and triquetrum are similar in humans and African apes, with fossil hominins largely within the range of these two groups. Capitate, scaphoid, trapezium and trapezoid of humans appear distinct from those of other taxa, with early fossil hominins largely intermediate between humans and African apes. For extant taxa, symbols represent species averages.

A tale as old as time: Young, attractive femme fatale lore appears in nearly every culture

Amazing stuff!

"... The collected data was then split into two groups based on the type of society they belonged to: egalitarian, where everyone has relatively equal power and resources, and complex societies, where large differences in wealth and power exist. ...

They found that these stories existed in almost all egalitarian and complex societies. So, the researcher suggests this isn't just a story shaped by powerful societies to control women—it's a pan-human theme that cuts across cultures. ...

The author also highlighted that these women are consistently portrayed as young and physically attractive across cultures ..."

From the abstract:

"This paper examines the cross-cultural prevalence of the femme fatale (dangerous woman) motif using folkloric materials, ethnographic accounts, and consultations with ethnographers across 84 societies.

Narratives were coded for depictions in which male protagonists suffer harm following involvement with an unfamiliar but physically attractive woman.

Results show that 94% of sampled societies contain recognizable femme fatale imagery.

When male motivation could be inferred, narratives overwhelmingly emphasized expectations of emotional attachment or long-term partnership rather than short-term sexual encounters. This pattern challenges interpretations that frame male involvement primarily in terms of sexual gratification or predatory intent.

Instead, the findings suggest that femme fatale narratives function as culturally mediated responses to recurrent mating dilemmas rooted in asymmetric emotional investment. More broadly, the study demonstrates how universal predispositions toward attraction and attachment are symbolically elaborated within culturally specific moral frameworks."

A tale as old as time: Young, attractive femme fatale lore appears in nearly every culture

Wanting Beauty, Fearing Beauty: Mate Preference, Intimacy, Deception, and the Femme Fatale (open access)

Only humans have chins: Study shows it's an evolutionary accident. Really!

Does it not provide any significant benefits to humans? How about speech and eating?

So far this paper is only published on PLOS.

The lead author Noreen von Cramon-Taubadel has only less than 4900 lifetime citations!

Why these authors even used the term "spandrel" (the space between the shoulders of adjoining arches) in the title of their paper?

"... "The chin evolved largely by accident and not through direct selection, but as an evolutionary byproduct resulting from direct selection on other parts of the skull," says Noreen von Cramon-Taubadel, Ph.D., professor and chair of the UB Department of Anthropology in the College of Arts and Sciences. ..."

From the abstract:

"Humans are unique among primates in possessing a chin, yet it is currently unclear whether the form of the symphyseal region of the mandible where the chin is located is the product of direct selection or a by-product of evolutionary pressures on other craniomandibular features.

Here, we conduct an evolutionary analysis of hominoid craniomandibular traits to test three hypotheses: symphyseal mandibular traits evolved

(1) neutrally due to genetic drift,

(2) under direct selection, and 

(3) as a by-product (or “spandrel”) of selection on other craniomandibular traits. Evolutionary rates of morphological change, via Lande’s generalized genetic distance, were estimated along each branch of a fully-resolved hominoid phylogeny to reveal patterns of neutral, stabilizing and directional selection.

Directional selection was detected along the branch between humans and the last common ancestor of chimpanzees and humans, against a backdrop of pervasive stabilizing selection and neutral evolution in hominoids. Significant directional selection was found on cranial traits reflecting increased basicranial flexion, neurocranial expansion, and reduction in lower facial prognathism, and on mandibular traits that generate a more parabolic-shaped, gracile mandible with a smaller ramus and shallower corpus.

In contrast, of the nine mandibular “chin” traits, only three were under significant direct selection, while the other six were either under no selection or indirect selection. Thus, the results are consistent with the hypothesis that the symphyseal morphology that forms the human chin evolved largely as a by-product (i.e., spandrel) [???] of direct selection for reduced anterior dental size and the craniofacial changes correlated with the evolution of bipedalism in hominins, rather than as a specific adaptation."

Only humans have chins: Study shows it's an evolutionary accident

Is the human chin a spandrel? Insights from an evolutionary analysis of ape craniomandibular form

Fig 2. Craniomandibular landmarks with all 22 cranial and 24 mandibular interlandmark distances considered here.

Landmark definitions can be found in S1 Table. Solid colored lines show the expected selection gradients to increase (red) and to decrease (blue) for the nine mandibular symphyseal traits related to the evolution of a chin under a hypothetical model of direct selection along the Homo sapiens branch since the last common ancestor with chimpanzees. [Notice, the authors forgot to explain the meaning of the capital letters!]

About the evolution of musicality, rhythm, and dancing

Amazing stuff!

"More than a hundred years ago, Charles Darwin’s ideas about the evolution of music were pitted against those of the sociologist Herbert Spencer . 

Darwin believed that the ability to make music evolved as a trait with adaptive value across different animal groups before the advent of contemporary humans, whereas Spencer believed that only humans can make true music.

Adaptive explanations for the evolution of human music still abound. In the absence of compelling fossil or archaeological evidence of music making, however, 21st century researchers rely as much on conjecture as they did in Darwin and Spencer’s time. ...

Do the findings of Rajendran et al. falsify the vocal-learning hypothesis by showing that a nonvocal learner can synchronize its motor responses to a musical beat and do this at different tempos? Rejecting the vocal-learning hypothesis would mean accepting that there is no mediation (neurobiological or otherwise) between vocal learning and beat processing.

However, rhythmically inclined monkeys and parrots are performing in a captive context and would not have the opportunity to learn such behaviors in their respective habitats. Rajendran et al. are careful to note that the abilities that were observed are not natural behaviors: They were conditioned through extrinsic rewards, not the seemingly intrinsic ones that humans experience when they follow rhythmic beats. A behavior that has been conditioned may not be equivalent to a behavior that emerges spontaneously. ..."

From the editor's summary and abstract:

"Editor’s summary

Musicality and especially moving to a beat—i.e., dancing—is a fundamental human trait. 

Very few other species have been found to do this, and all of these species are vocal learners, leading to the conclusion that such a tendency is reserved for species with this ability.

Notably, most nonhuman [???] primates are not vocal learners, leading to an evolutionary conundrum with regard to when our own ancestors may have begun to dance. Rajendran et al. now show that macaques are capable of synchronizing taps to a real musical beat and choose to do so spontaneously ...

Abstract

Synchronizing movements to music is a hallmark of human culture, but its evolutionary and neurobiological origins remain unknown.

This ability requires

(i) extracting a steady rhythmic pulse, or beat, out of continuous sounds;

(ii) projecting this pattern forward in time; and

(iii) timing motor commands to anticipate future beats.

Here, we demonstrate that macaques can synchronize to a subjective beat in real music and even spontaneously do so over alternative strategies.

This contradicts the influential “vocal-learning hypothesis” that musical beat synchronization is privileged to species with complex learned vocalizations.

We propose an alternative view of musical beat perception and synchronization as a continuum onto which different species can be mapped based on their capacity to coordinate the general abilities listed above through association with reward."

In Science Journals | Science

Groove to the music "What can tapping macaques reveal about the evolution of musicality?"

Monkeys have rhythm (open access)

Fig. 1. Macaques synchronize their taps to music.

Human Dominance Soars While Wild Biomass and Movement Decline. Really!

So what is the point of these two new studies? Biomass hysteria and alarmism? Exercises in futility?

In 1850, world human population was around 1.2 billion. In 2025, it is about 8.2 billion. So what! The population of China and Japan are already shrinking, while the population of India, Africa and Europe will follow soon.

Human Dominance Soars While Wild Biomass and Movement Decline - www.caltech.edu "Two new studies quantify key features of human and animal presence on Earth.

The first study finds that the movement of human biomass today is 40 times greater than that of all wild land mammals, birds, and arthropods combined. Another study reveals that the combined biomass of wild land and marine mammals has plummeted by about 70 percent since 1850, whereas the biomass of humans has soared by roughly 700 percent and that of domesticated animals by 400 percent; those two categories have a combined biomass approaching about 1.1 billion tons."

Discovery of four stone megastructures in Europe could change our view of prehistoric societies

Amazing stuff!

"Scientists have discovered evidence of stone megastructures on the Karst Plateau on the border of Slovenia and Italy that were most likely built before the Late Bronze Age. These enormous structures have long, low walls that lead to a pit and are believed to have been used as large-scale traps for herds of wild animals such as red deer.

Researchers ... conducted airborne laser scanning (ALS) surveys across an area of approximately 870 square kilometers and discovered four previously unknown megastructures. They range in size from 530 meters to over 3.5 kilometers in length and are similar to desert kites, large prehistoric hunting structures in Southwest Asia and North Africa. ..."

From the significance and abstract:

"Significance

Monumental dry-stone structures identified on the Karst Plateau of the Adriatic hinterland through airborne laser scanning represent a previously undocumented form of large-scale hunting infrastructure in Europe. Characterized by funnel-shaped alignments and concealed enclosures, they appear designed to guide and intercept herds of ungulates.

Although precise dating remains challenging, radiocarbon and stratigraphic evidence point to a likely pre- or early Bronze Age construction.

Their scale and strategic landscape integration imply coordinated communal effort, planning, and knowledge of animal behavior. These findings extend the known geographic range of prehistoric hunting megastructures beyond the arid landscapes of Southwest Asia and North Africa, offering insights into prehistoric land use, social organization, and subsistence in temperate Europe.

Abstract

Airborne laser scanning survey of the Karst Plateau in the Adriatic hinterland has revealed four monumental dry-stone structures, characterized by long, low stone alignments converging into concealed enclosures. These features, strategically placed along natural movement corridors, appear to have been designed to guide and trap herds of wild animals.

Their architectural scale, complexity, and integration with the terrain suggest a high degree of communal organization, landscape knowledge, and planning. Although direct dating remains inconclusive, associated stratigraphy indicates they were abandoned before the Late Bronze Age, pointing to a potentially earlier origin.

These structures may represent the westernmost examples of a broader tradition of large-scale hunting installations previously known only from the arid zones of Southwest Asia and North Africa. Their finding challenges prevailing models of prehistoric subsistence in Europe and opens broad perspectives on social organization, mobility, and human–animal relations in complex landscapes."

Discovery of four stone megastructures could change our view of prehistoric societies

Prehistoric hunting megastructures in the Adriatic hinterland (open access)

Fig. 1 Location of the study area in the northern Adriatic hinterland, showing the position of the four funnel-shaped stone structures discussed in the text. The map highlights key landscape features, situating the installations within broader topographic corridors that connect the Gulf of Trieste with the interior.

Fig. 2 Plans of the four monumental funnel-shaped structures (K01-K04) based on airborne laser scanning (ALS) data. 

Humans are The Only Ones With Chins - And We Don't Know Why

Recommendable! You may want to scratch your chin! (This function was not even mentioned in the video). I don't take that on my chin! 😊

Genetic alterations in Kenya's nomadic Turkana people allows them to survive in extreme arid regions

Amazing stuff! This research was first published in January 2023. Not fresh, but not stale! 😊

"The Turkana communities of northern Kenya live in one of the most arid regions on Earth. Perhaps unsurprisingly, when researchers tested blood and urine samples, they discovered that about 90% of the people are dehydrated. What was surprising, however, was that they were generally healthy in spite of this. Their secret? Genetic adaptations that help them fare well with less water. ...

The researchers also looked at gene expression profiles in Turkana people who now live in cities and compared them to the expression patterns of Turkana pastoralists. There was more evidence of selection in the genes that differed between the two groups than in genes that didn’t ..."

From the abstract of the Perspective:

"Despite being genetically homogeneous compared with other animals, humans are geographically diverse and have evolved to meet the demands of local environments, pathogens, and diets.

In 1962, James Neel proposed that genes that predispose people to metabolic diseases may have been advantageous in the evolutionary past.

Yet empirical support for his hypothesis remains limited.  ... Lea et al. report genomic analyses of samples from the Turkana people in northwest Kenya that reveal a more nuanced narrative. The Turkana have practiced nomadic pastoralism (raising and herding of livestock) in extreme arid environments for ~5000 to 8000 years.

The authors analyzed 367 genomes and discovered adaptations to ecological pressures, particularly chronic water scarcity. They identified physiological compromises in kidney function that improved water retention but mildly increased the amounts of urea in the blood. This context-specific trade-off may become pathological as Turkana populations urbanize."

From the editor's summary and abstract:

"Editor’s summary

Humans have adapted to many environments, dietary shifts, and conditions. Lea et al. analyzed blood markers and genomes from 367 Turkana individuals in northwest Kenya ... This group has primarily practiced nomadic pastoralism in an extremely arid environment for the past 5000 to 8000 years, with as much as 80% of their traditional diet being composed of animal products. The authors identified several regions of the genome that appear to be under recent selection, including one near the gene STC1, which is involved in the kidneys’ response to dehydration. The authors also shared the results with these groups, which may help them be more aware of possible medical complications as some individuals move to urban centers. ...

Abstract

The Turkana pastoralists of Kenya inhabit arid, water-limited environments and rely largely on livestock for subsistence. Working with Turkana communities, we sequenced 367 whole genomes and identified eight regions with evidence for recent positive selection. One of these regions includes a putative regulatory element for STC1—a kidney-expressed gene involved in metabolism and the response to dehydration. We show that STC1 is induced by antidiuretic hormone in human cells, is associated with urea levels in the Turkana themselves, and is under strong and recent selection in this population as well as a second East African population, the Daasanach.

This work highlights how integrating anthropological and genomic approaches can lead to a new understanding of human physiology with biomedical relevance."

ScienceAdviser

Partnership with Kenya's Turkana community helps scientists discover genes involved in adaptation to desert living

Trade-offs and human adaptation at the extremes (Perspective, no public access) "Genomic analyses of Turkana pastoralists identify variants that increase water retention"

Adaptations to water stress and pastoralism in the Turkana of northwest Kenya (no public access)

Adaptations to water stress and pastoralism in the Turkana of northwest Kenya (preprint, possibly outdated, open access)

Girl power: Female gorillas outrank males twice their size. Really!

When AAAS tries to sell feminist propaganda as science! May we call it junk science!

Maybe these males were the old or young or was otherwise handicapped (e.g. injury) etc.!

What about alpha females or larger than normal females? This was not investigated so it seems.

"In concrete jungles all over the world it feels like men and women are constantly competing for dominance. As human women navigate gendered pay gaps [???] and modern dating culture, their gorilla cousins [???] in actual jungles have to deal with their own challenges, such as being half the size of their male counterparts. ... Now, a new study calls into question this “male power archetype” by finding that female mountain gorillas actually outrank some males.

The researchers analyzed 25 years of behavioral data collected on 55 adult mountain gorillas in Uganda to understand the power dynamics between females and males. They found that even though each group was led by an alpha male, 88% of females outranked at least one male. ..."

From the highlights and abstract:

"Highlights

• Female mountain gorillas can outrank males despite being half their size

• In our study, females won 28% of agonistic interactions against adult non-alpha males

• Females had feeding priority over males they outranked

Summary

Males have been long assumed to strictly outrank females in all but a few mammals, potentially due to male-biased size dimorphism emerging from male-male competition and female mate choice. 

However, recent work questions these traditional [feminist] views [???], suggesting that intersexual power varies along a continuum from strictly male- to strictly female-biased and is not a static species attribute.

We used a 25-year dataset to examine the intersexual power dynamics in wild mountain gorillas, considered a prominent example of strict male power.

Although the highest-ranking individual in each of the four study groups was male, 88% of females outranked at least one adult male in multi-male groups.

Females won 28% of agonistic interactions against non-alpha males, predominantly when these males were young adults or old. Our results did not support that females gain power over males due to mating-based leverage, as a byproduct of male-male competition, or due to female-female support, but they suggested that females may gain power over non-alpha males due to alpha male support and by leveraging commodities not directly linked to mating.

Females always had feeding priority on a valued monopolizable resource over non-alpha males they outranked and, in half of the cases, over non-alpha males overall, highlighting a functional component of female empowerment.

Our study questions the “male power archetype” [an invention by feminists] assumption in a hominid that exhibits extreme male-biased sexual size dimorphism and, thus, it calls for future work to investigate similar long-standing assumptions regarding the evolutionary origins of intersexual relationships across species."

ScienceAdviser

Female mountain gorillas can outrank non-alpha males (open access)

Graphical abstract

Ancient Tiwanaku temple discovered in Bolivia

Amazing stuff!

"Long before the Inka (commonly known as Inca in English) rose to power, a mysterious civilization bloomed on the edge of Lake Titicaca. Known as Tiwanaku, it began as a humble farming village in the Bolivian highlands and, by around 500 BCE, grew into a sprawling city-state that influenced much of the Andean world. ...

Long before the Inka ruled the Andes, the Tiwanaku civilization carved out one of the region’s earliest and most influential societies. ...

Now, a team of researchers has uncovered a remarkable temple site 215 km (134 miles) from Tiwanaku’s core. This newly found structure, with its sunken courtyard and massive stone layout, mirrors Tiwanaku’s famous ceremonial platforms. ...

Tiwanaku, one of the Andes’ earliest urban societies, flourished with pyramids, sunken temples, and towering monoliths. But around 1000 BCE, it mysteriously collapsed. By the time the Inka arrived centuries later, Tiwanaku was already a shadow of its former glory. ...

Archaeologists uncovered a large ancient temple named Palaspata, spanning the size of a city block approximately 125 meters long by 145 meters wide (410 x 475 ft) with 15 enclosures around a central sunken courtyard. Its design appears aligned with the solar equinox, suggesting a ritual function. ..."

"An ancient society near the southern shores of Lake Titicaca in modern-day Bolivia was once one of the continent’s most powerful civilizations. Known as Tiwanaku, the ancient society is widely considered by archaeologists to be one of the earliest examples of civilization in the Andes and a precursor of the Inca empire, but it mysteriously disappeared about a thousand years ago. ..."

From the abstract:

"The nature and extent of the Tiwanaku state expansion in the Andes during the second half of the first millennium AD continues to be debated.

Here, the authors report on the recent discovery of an archaeological complex 215km south-east of Tiwanaku, where a large, modular building with an integrated, sunken courtyard strongly resembles a Tiwanaku terraced platform temple and demonstrates substantial state investment. Constructed, the authors argue, to directly control inter-regional traffic and trade between the highlands and the eastern valleys of Cochabamba, the complex represents a gateway node that effectively materialised the power and influence of the Tiwanaku state."

Ancient Tiwanaku temple discovered in Bolivia

Ancient temple ruins discovered in Andes shed light on lost society (original news release)

Gateway to the east: the Palaspata temple and the south-eastern expansion of the Tiwanaku state (open access)

This is digital reconstruction of the temple revealing a complex about the size of a city block. Called Palaspata after the native name for the area, the site was strategically perched at the crossroads of several ancient trade routes.

Study says left-handed individual aren’t more creative after all

Update: I believe this spurious correlation between left-handedness and genius was discovered already decades ago, i.e. two rare events occurring together may be unrelated.

Recommendable! Food for thought! Maybe the most important takeaway: Left-handed individuals are often not forced anymore to become right-handed. It has become accepted.

If I remember correctly, I knew someone left-handed in my childhood who was forced to learn to be right handed.

Metallurgy’s surprisingly ancient origins dating to about 8800 BCE

Amazing stuff! Maybe the Stone Age was not so stony at all. Give our ancestors some credit! They were experimenting and getting ready for the next stage. 😊

"Guinness World Records recognizes as the world’s oldest written customer complaint a 3700-year-old clay tablet accusing the Mesopotamian trader Ea-nāṣir of peddling crappy copper. No complaints about the copper from the Anatolian archaeological site known as Gre Filla, though. Here, a team of scientists reports evidence of what may be some of the earliest experiments with smelting copper.

In a sedimentary layer dating to around 8800 B.C.E., archaeologists unearthed an amorphous, glasslike lump of soil with a greenish yellow sheen and a ruddy bottom. Weighing about half a kilogram, it looked like it had melted on one side. In the same layer, they found a copper bar. When the researchers analyzed the artifacts’ chemical composition, they found evidence that the copper-flecked soil had been heated at high temperatures, then rapidly cooled—a sign of smelting. The copper bar had a porous structure that suggested it may have been formed from smelted metal.

While the scientists can’t say for sure if the people here were smelting copper—they haven’t found smoking-gun evidence like slag or a furnace—other experts say it’s a definite possibility. And it would suggest the hunter-gatherers who lived in the region were experimenting with metallurgy long before they adopted agriculture and built cities—and long before Ea-nāṣir received his historic one-star review."

"... In Europe, the oldest definitive evidence of smelting comes from Serbia around 5000 B.C.E. ..."

From the highlights and abstract:

"Highlights

• Gre Fılla appears to have been a location where key metallurgical principles—such as controlled heating, casting, and potential ore processing—were actively explored.

• Vitrified material (GRE-VRF) shows signs of high-temperature exposure, as evidenced by high-temperature mineral phases, FTIR/XRD transformations, and microstructural features indicating rapid cooling.

• Chromite grains and copper droplets in GRE-VRF support its relation to copper processing.

• Chromite inclusions and porosity in the bar-shaped copper object (GRE-C-002) strengthen the link to copper production at Gre Fılla.

• Lead isotope analysis of the GRE-C-002 reveals long-distance connections, with Trabzon as the source.

Abstract

The “Neolithic transformation” is characterized by major changes in human history, including advancements in cognitive skills, technological knowledge, social organization, and the establishment of permanent settlements with elaborate architecture.

Around 12,000 years ago, Anatolia became a key region as hunter-gatherer communities transitioned to a settled lifestyle. Its rich natural resources, including lithic raw materials and metal ores, played a crucial role in supporting early human settlement and technological advancements.

The origins of metallurgy have generally been classified following a sequence of technological development influenced by social and cultural organization.

The artifacts related to copper production at Gre Fılla were examined using a multi-analytical approach, including X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM–EDS), Fourier transform infrared spectroscopy (FTIR), flame atomic absorption spectroscopy (FAAS), inductively coupled mass spectroscopy (ICP-MS), and handheld X-ray fluorescence (pXRF).

The results support the hypothesis that prehistoric experimentation likely played a role in leading to different pathways of development in each region. Our findings suggest a multifaceted picture of the early Neolithic period in Eurasia, including the spread of innovation packages, local traditions, and adaptations."

ScienceAdviser

This lump of melted soil may push back the origin of metallurgy by thousands of years (no public access)

Early copper production by the last hunter-gatherers (no public access)

The Gre Filla site in Anatolia in Turkey Gre Fılla excavation archive 2018–2023

This misshapen lump of molten soil may represent the earliest evidence yet of copper smelting.  Gre Fılla excavation archive 2018–2023