Fetal load and the evolution of lumbar lordosis in bipedal hominins.

Nature

Department of Anthropology, Harvard University, 11 Divinity Avenue, Cambridge, Massachusetts 02138, USA.

Published: December 2007

As predicted by Darwin, bipedal posture and locomotion are key distinguishing features of the earliest known hominins. Hominin axial skeletons show many derived adaptations for bipedalism, including an elongated lumbar region, both in the number of vertebrae and their lengths, as well as a marked posterior concavity of wedged lumbar vertebrae, known as a lordosis. The lordosis stabilizes the upper body over the lower limbs in bipeds by positioning the trunk's centre of mass (COM) above the hips. However, bipedalism poses a unique challenge to pregnant females because the changing body shape and the extra mass associated with pregnancy shift the trunk's COM anterior to the hips. Here we show that human females have evolved a derived curvature and reinforcement of the lumbar vertebrae to compensate for this bipedal obstetric load. Similarly dimorphic morphologies in fossil vertebrae of Australopithecus suggest that this adaptation to fetal load preceded the evolution of Homo.

Download full-text PDF

Source
http://dx.doi.org/10.1038/nature06342DOI Listing

Publication Analysis

Top Keywords

fetal load
8
lumbar vertebrae
8
load evolution
4
lumbar
4
evolution lumbar
4
lumbar lordosis
4
lordosis bipedal
4
bipedal hominins
4
hominins predicted
4
predicted darwin
4

Similar Publications

Background: Allowing a birth companion is the basic right of a mother and is identified as an important component of respectful maternity care. The implementation of this intervention has been a challenge in heavy-load public health facilities in India.

Local Problem: Despite the proven benefits of the presence of birth companions on maternal-fetal outcomes, there was no policy of allowing birth companions in our hospital.

View Article and Find Full Text PDF

Eicosapentaenoic Acid and Docosahexaenoic Acid as an Antimicrobial Agent in Orthopedics-An In Vitro Study About the Race for Surface.

Pathogens

January 2025

Research Laboratory for Biofilms and Implant Associated Infections (BIOFILM LAB), University Hospital for Orthopaedics and Traumatology, Medical University of Innsbruck, Müllerstraße 44, 6020 Innsbruck, Austria.

Background: The burden of prosthetic joint infection in combination with antibiotic-resistant bacterial strains is a rising dilemma for patients experiencing total joint replacements. Around 0.8-2% of patients experience prosthetic joint infections, while up to 21% of patients are considered fatal cases after 5 years.

View Article and Find Full Text PDF

Background: Although several conditions and specific risk factors have been associated with stillbirth (SB), in most of the cases it is difficult to identify the definitive etiopathology and cause of death. Specifically, the role of infections in SB is still debated. Our aim was to study maternal, placental, and fetal tissues in cases of SB in order to define the causative link between infections and fetal death, through a multidisciplinary clinical audit.

View Article and Find Full Text PDF

: The use of antibiotics in livestock contributes to antimicrobial resistance, highlighting the need for alternative solutions. Among these, chelating agents, like ethylenediaminetetraacetic acid (EDTA) and Chitosan, have shown potential in reducing bacterial contamination in seminal doses used in artificial insemination (AI), while preserving sperm quality. The objective of this study was to evaluate the potential use of EDTA and Chitosan as alternatives to antibiotics for the liquid storage of rabbit seminal AI doses.

View Article and Find Full Text PDF

Background: The early colonization and establishment of the microbiome in newborns is a crucial step in the development of the immune system and host metabolism. However, the exact timing of initial microbial colonization remains a subject of ongoing debate. While numerous studies have attempted to determine the presence or absence of intrauterine bacteria, the majority of them have drawn conclusions based on sequencing data from maternal or infant samples taken at a single time point.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!