The unusually long lifespans of humans and the persistence of post-reproductive lifespans in women represent evolutionary puzzles because natural selection cannot directly favour continued living in post-menopausal women or elderly men. Suggested sources of indirect selection require genetic correlations between fitness and survival or reproduction at younger ages, reproduction in the opposite sex, or late-life contributions to offspring or grandoffspring fitness. Here we apply quantitative genetic analyses to data from a historical human population to explicitly test these evolutionary genetic hypotheses. Total genetic selection increased the male post-50 lifespans by 0.138 years per generation; 94% of this arose from indirect selection acting to favour early-life fitness in both sexes. These results argue strongly against life-history models of ageing that depend on trade-offs between reproduction and late-life survival. No source of indirect selection for female post-50 lifespan was detected, deepening the mystery of why female post-reproductive survival persists. This result is probably due to recent changes in the genetic architecture of female lifespan, and it highlights the need for similar quantitative genetic analyses of human populations at other points along demographic transitions.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1038/s41559-017-0329-x | DOI Listing |
Hormones (Athens)
January 2025
LABIOEX-Exercise Biology Lab, Department of Health Sciences, UFSC-Federal University of Santa Catarina, Araranguá, SC, Brazil.
The endocannabinoid system (ECS), regulating such processes as energy homeostasis, inflammation, and muscle function, centers around cannabinoid receptors, including CB1. These receptors are mainly located in the central nervous system and skeletal muscles. Hyperactivity of CB1 receptors is linked to metabolic disorders and chronic inflammation, highlighting their potential as therapeutic targets for muscle hypertrophy and metabolic health.
View Article and Find Full Text PDFUnlabelled: Motivated behaviors are regulated by distributed forebrain networks. Traditional approaches have often focused on individual brain regions and connections that do not capture the topographic organization of forebrain connectivity. We performed co-injections of anterograde and retrograde tract tracers in rats to provide novel high-spatial resolution evidence of topographic connections that elaborate a previously identified closed-loop forebrain circuit implicated in affective and motivational processes.
View Article and Find Full Text PDFFront Immunol
January 2025
Jiangsu Engineering Research Center of Biological Data Mining and Healthcare Transformation, Xuzhou Medical University, Xuzhou, China.
Introduction: Brucellosis is a widespread zoonotic disease that poses a considerable challenge to global public health. Existing diagnostic methods for this condition, such as serological assays and bacterial culture, encounter difficulties due to their limited specificity and high operational complexity. Therefore, there is an urgent need for the development of enhanced diagnostic approaches for brucellosis.
View Article and Find Full Text PDFInt J Gen Med
January 2025
Department of Respiratory and Critical Care Medical Department Infectious Diseases Ward, The Traditional Chinese Medicine Hospital Affiliated to Xinjiang Medical University, Urumqi, Xinjiang, People's Republic of China.
Background: This study examines the distribution characteristics of pathogenic bacteria in respiratory infections and their relationship with inflammatory markers to guide clinical drug use.
Methods: We selected 120 patients with lower respiratory tract infection in the electronic medical record system of Xinjiang Provincial People's Hospital from March 2019 to March 2023 for a case-control study. Using Indirect Immunofluorescence Antibody test(IFA), blood routine, C-reactive Protein (CRP), and High-sensitivity C-reactive Protein(hsCRP), we detected nine respiratory pathogens (Respiratory syncytial virus; Influenza A virus; Influenza B virus; Parainfluenza virus; Adenovirus; Mycoplasma pneumoniae; Chlamydia pneumoniae; Legionella pneumophila type 1; Rickettsia Q) in all patients and analyzed their distribution and correlation.
Int J Clin Pediatr Dent
December 2024
Department of Pediatric and Preventive Dentistry, M A Rangoonwala College of Dental Science and Research Centre, Pune, Maharashtra, India.
Background: Indirect pulp treatment (IPT) is often employed in dentistry as a valuable technique for preserving dental vitality. While mineral trioxide aggregate (MTA) remains a popular choice, the need for materials with shorter setting times, lower costs, and minimized discoloration concerns has led to the exploration of alternative options.
Aim: To evaluate and compare the radiographic and clinical outcomes of gel-based MTA Kids e-MTA (Kids-e-Dental, Mumbai, India) with MTA (ProRoot MTA, Dentsply Tulsa, Johnson City, TN, USA).
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!