Human mitochondrial DNA diversity is compatible with the multiregional continuity theory of the origin of Homo sapiens

Confidence intervals for estimates of human mtDNA sequence diversity, chimpanzee-human mtDNA sequence divergence, and the time of splitting of the pongid-hominid lineages are presented. Consistent with all the data used in estimating the coalescence time for human mitochondrial lineages to a common ancestral mitochondrion is a range of dates from less than 79,000 years ago to more than 1,139,000 years ago. Consequently, the hypothesis that a migration of modern humans (Homo sapiens) out of Africa in the range of 140,000 to 280,000 years ago resulted in the complete replacement, without genetic interchange, of earlier Eurasian hominid populations (Homo erectus) is but one of several possible interpretations of the mtDNA data. The data are also compatible with the hypothesis, suggested earlier and supported by fossil evidence, of a single, more ancient expansion of the range of Homo erectus from Africa, followed by a gradual transition to Homo sapiens in Europe, Asia, and Africa.

Functional capacity and risk of frailty syndrome in 85-year-old and older women living in nursing homes in Poland

Maintaining sufficient physical fitness to prevent any limitations in performing activities of daily living and to be functionally independent is of great importance for both longevity and quality of life in older adults. Aim of the study was to evaluate functional physical fitness of women aged 85 years and older, residents of nursing homes, in the Polish population and to assess the risk of frailty syndrome. The study involved 17 women aged 85 years or older, residents of nursing homes in the Lower Silesian voivodeship. The Senior Fitness Test was used to assess functional fitness. The results of functional fitness tests were related to the standards for the elderly population in Poland and to the reference standards for maintaining independence. In addition, hand grip strength level was measured using a hand dynamometer, height and weight were measured, and BMI was calculated. 15-item version of the Geriatric Depression Scale was used to assess the level of depression. We used 3 of the 5 proposed criteria from the Cardiovascular Health Study Frailty Index to assess the presence of frailty syndrome: gait speed, level of hand grip strength, and the presence of depression. The results of the Senior Fitness Test demonstrate the low level of functional fitness of female nursing home residents. A large percentage of the women surveyed are below the standard values developed for Polish seniors. The weakest results were in the timed up and go test, with more than 94% of the women tested falling outside the standard ranges. The mean results of all samples do not meet the developed reference standards for maintaining independence. No non-frail person was found among the study participants and the vast majority were at risk for frailty syndrome. Most of the studied women do not meet functional fitness standards developed for the Polish population, as well as reference standards for maintaining independence. Nursing home residents over the age of 85 are at risk for frailty syndrome.

Interpopulational variation in human brain size: implications for hominin cognitive phylogeny

Throughout the hominin lineage brain size is believed to have increased threefold – increase which, it is argued by some researchers, results in the enhanced brain power that distinguishes humans from any other living being. However, as we demonstrate in this article this supposed increase is the result of comparing the species mean of contemporary humans with other great apes and fossil hominins. This method obscures both interpopulational variation among modern humans, and the fact that the putative increases in the mean are the result of an increase in the upper limit in some populations, which has the result of obscuring the relative stasis in the lower limit over the last 600k years. For example, populations such as Aboriginal Australians have a range that is more different from Danes than it is from that of Asian H. erectus over the last 600ka. Yet Aboriginal Australians, whose unique anatomy seems to be related to the climatic conditions of Australia, possess all of the socio-cognitive traits characteristic of all other modern-day populations – yet they seemed not to have undergone increase in brain size to the degree that many other populations have. In this instance brain size seems to be unrelated to cognition. In this article we present a statistical analysis of interpopulational variation in contemporary humans and why such an analysis is crucial for our understanding of hominin cognitive, social and technological evolution. We also suggest how such variation may add to our understanding of hominin ontogeny or life history. Additionally, we develop a model based on humanity’s unique form of embodied social cognition that results from our upright bipedal posture and hand morphology. This model is then used to explain the results of our statistical analysis and the possible factors underpinning the human emergence.

The impact of cigarette smoking on the quality of sleep in Polish men

Quality of sleep directly impacts quality of life, whilst lifestyle significantly impacts night rest. Cigarette smoking is a serious threat to overall health, including sleep. Nicotine in cigarettes affects the nervous system, whilst the respiratory system is impacted by carcinogenic substances, such as dusts and tarred substances, inhaled with smoke. Cigarettes are assumed to be a risk factor in sleep disorders, including breathing sleep disorders. This study’s aim was to analyze the impact of cigarette smoking on adult men’s polysomnographic parameters. Polysomnographic records for 94 adult men were obtained from the polysomnography laboratory in Opolskie Province, Poland. Additionally co-morbidities, height, weight and frequency of smoking were also noted. Three groups of men were categorised according to the frequency with which they smoked: non-smokers, smoking less than a pack a day, smoking more than a pack a day. Compared to non-smokers and mild smokers, men who were heavy smokers also exhibited the longest sleepless time (H=8.11; p=0.017), the maximum waking time following the onset of sleep (H=7.99; p= 0.018), the lowest sleep efficiency across the three groups (H=7.96; p=0.019), the greatest number of apnea events per hour of sleep (H=6.23; p= 0.045), the lowest Oxygen Level Nadir (H=11.44; p= 0.003) and the highest rate of limb movements per hour of sleep (H=9.81; p=0.007). The dose effect was identified, which correlated more cigarettes men smoked per day with lower sleep quality.

Assessment of the influence of physical activity and screen time on somatic features and physical fitness in 6 to 7-year-old girls

Aim of the study is to assess the relationship between screen time, physical activity and physical fitness among girls 6–7 years-old. 21,528 girls aged 6 and 7 from Poland were assessed in terms of physical fitness. Arm strength, abdominal strength and explosive strength of the lower limbs were measured using the EUROFIT test. Basic somatic features were measured and BMI and WHtR indices were calculated. Spontaneous and organized physical activities as well screen time were assessed by the parents utilizing a questionnaire. The multiple logistic regression method was used to evaluate the influence of screen time and spontaneous physical activity on various components of physical fitness. Physically active (PA) girls (≥1h/day) and those who participated in additional physical activities (APA) during the week had significantly higher height, weight, and BMI (p<0.001), but not WHtR. They had a higher level of flexibility, explosive strength of the lower limbs and arm strength (p<0.001). With an increase in screen time, the BMI, WHtR increased significantly and explosive strength of the lower limbs, abdominal strength and arm strength were lower. Regression analysis showed that more frequent participation in extracurricular activities increased the values of BMI and WHtR in quartile 4 (Q4), and strength components: Q2–Q4 (p<0.05). Spontaneous physical activity was positively related to the values of BMI, WHtR (both: Q4; p<0.05), explosive force of lower limbs (Q3–Q4; p=0.001), and negatively related to arm strength (Q2; p=0.001). Screen time (≥2hrs/day) increased odds for higher BMI values (p<0.05). Each screen time category decreased the odds of achieving abdominal muscle strength related to the quartiles: Q2–Q4 (p<0.05), arm strength (Q4: p<0.05). ST (1 <2hrs/day) decreased arm strength (Q3; p= 0.045). Our research has shown that screen time-related sedentary behavior and physical activity affect overweight and obesity indices (especially BMI) and strength abilities. The observed associations more often affected girls with a higher level of fitness The results observed in girls aged 6-7 indicate a need for early intervention aimed at limiting time spent watching TV and computer use, as well as to encourage both spontaneous and organized physical activities.

Exploring the effects of birth order on human lifespan in Polish historical populations, 1738–1968

While the relationships between birth order and later outcomes in life, including health and wealth, have been the subject of investigation for several decades, little or no data exist regarding the relationship between birth order and life expectancy in the Polish population. The aim of this study was to explore the link between birth order and lifespan in Polish historical populations. We obtained 8523 records from a historical dataset that was established for parishioners from the borough of Bejsce, including 4463 males and 4060 females. These data pertain to the populations that lived over a long period in a group of localities for which parish registers were well preserved. The Mann-Whitney U test, the Kruskal-Wallis ANOVA and ANCOVA were run. The results strongly suggest that birth order affects male longevity. However, no such association was found for females. On balance, the hypothesis that first-born boys live longer because they are born to relatively younger parents has received some empirical support and deserves further study. We hypothesise that the effects of birth order on human health and lifespan might be overshadowed by other factors, including educational attainment, socioeconomic status and lifestyle.

Cognitive and behavioral modernity in Homo erectus: skull globularity and hominin brain evolution

In this article we provide evidence that evolutionary pressures altered the cranial base and the mastoid region of the temporal bone more than the calvaria in the transition from H. erectus to H. sapiens. This process seems to have resulted in the evolution of more globular skull shape – but not as a result of expansion of the brain in the parietal regions but of reduction of the cranial base and the mastoid region relative to the parietals. Consequently, we argue that expansion of the parietals seems to be unrelated to brain evolution, but is more a by-product of reduction in other regions of the skull, reduction that may be related to dietary factors. Additionally, these findings suggest that cognitive and behavioural modernity may not necessarily be dependent on brain shape. Also, it cannot be attributed to the change in brain size because H. erectus and modern human cranial capacities overlap substantially. Consequently, we suggest H. erectus possessed the full suite of cognitive adaptations characteristic of modern humans without possessing a globular skull with flared parietals. Our results also support the theory that paedomorphic morphogenesis of the skull was important in the transition from H. erectus to H. sapiens and that such changes may be related to both dietary factors and social evolution.

Anthropometric measures and biomarkers for cardiovascular disease risk factors: evidence from a study of Polish adults participating in the cardiovascular disease prevention program (CHUK)

The Polish national program for the prevention of cardiovascular disease (CHUK) uses the Systematic Coronary Risk Evaluation (SCORE) index which evaluates the upcoming risk of death from cardiovascular causes for a 10 year period, based on information such as age, systolic blood pressure, cholesterol levels, smoking and gender. The aim of this study was to determine health indicators in the population enrolled in the program and identify the relationships between the cardiovascular risk factors. The data was collected from 303 participating individuals; 172 women (aged 35 to 58 years) and 131 men (aged 31 to 60 years). The SCORE index showed a statistically significant positive relationship between CVD and the male gender. The higher frequency of 3–4% and 5–9% for SCORE index in men indicates that they were at a higher risk of cardiovascular incidents. The increased risk of a cardiovascular incidence in men was associated with a higher mean arm circumference, waist circumference, BMI, systolic blood pressure, diastolic blood pressure, total cholesterol, LDL cholesterol, triglyceride and fasting glucose. HDL cholesterol and heart rate were statistically significantly higher in women. Among the study subjects, the most common parameters above the normal range were elevated LDL cholesterol and total cholesterol. The highest correlation with the SCORE index was observed for the age of the subjects, total cholesterol and LDL cholesterol, regardless of gender. The results showed that biochemical parameters and blood pressure were above normal values in almost all subjects. Men had significantly less favorable parameters compared to women of similar age range. According to the SCORE index, total cholesterol and LDL cholesterol significantly increased the risk of cardiovascular incident regardless of gender. Women were characterized by a lower risk of cardiovascular incident according to the SCORE index.

Low birth weight and birth weight status in Bangladesh: A systematic review and meta-analysis

The prevalence of low birth weight (LBW) is high in Bangladesh, but no study has collated recent estimates of LBW prevalence from throughout the country. The aim of this meta-analysis was to evaluate the prevalence of LBW and birth weight status in Bangladesh. We searched PubMed, Medline, Ovo and Google Scholar to find published articles in national and international journals from 2000–2020 and reviewed for relevance. Meta-analysis and Q test were performed to estimate the prevalence and heterogeneity of LBW from all included articles. Meta-regression was done to quantify associations with sample size and study year. Stratified analysis was conducted and effect size calculated for differences in LBW prevalence by sex, division and urban/rural area. In total 48 studies with 166,520 births were found and included in this meta-analysis. The pooled prevalence of LBW was 29.1% (95% CI, 28.9–29.3%) in overall, 29.9% (29.7–30.2%) in rural and 15.7% (14.9–16.6%) in urban areas. There was no significant difference in average birth weight between boys and girls (SD, 0.71; 95% CI, −0.43–1.83). Prevalence of LBW was higher in north-east Bangladesh compared to other zones (p<0.05). The pooled prevalence of LBW did not change significantly for last two decades. The prevalence of LBW in Bangladesh remains high. Lack of improvement suggests an urgent need for scaled up maternal and prenatal interventions and services known to reduce LBW. Urban/rural and divisional differences in rates suggest areas of greatest need.

An etiology of human modernity

Following the refutation of the replacement hypothesis, which had proposed that a ‘superior’ hominin species arose in Africa and replaced all other humans existing at the time, the auto-domestication hypothesis remains the only viable explanation for the relatively abrupt change from robust to gracile humans in the Late Pleistocene. It invokes the incidental institution of the domestication syndrome in humans, most probably by newly introduced cultural practices. It also postulates that the induction of exograms compensated for the atrophy of the brain caused by domestication. This new explanation of the origins of modernity in humans elucidates practically all its many aspects, in stark contrast to the superseded replacement hypothesis, which explained virtually nothing. The first results of the domestication syndrome’s genetic exploration have become available in recent years, and they endorse the human self-domestication hypothesis.