Source Themes

The outline of the pubic symphyseal surface is sexually dimorphic and changes with age in humans

The bony symphyseal surface is an important trait for age-at-death estimation from human skeletal remains. In this paper, we demonstrate for the first time that the outline of the human symphyseal surface is sexually dimorphic and that it changes …

Did population differences in human pelvic form evolve by drift or selection?

Pelvic dimensions differ, on average, among modern human populations. Some recent studies have reported that population differences in pelvic form evolved mainly by neutral processes, without considerable natural selection. This is a surprising claim …

Correlation of the human pubic symphysis surface with age‐at‐death: a novel quantitative method based on a bandpass filter

Age-at-death estimation from skeletal remains typically utilizes the roughness of pubic symphysis articular surfaces. This study presents a new quantitative method adapting a tool from geometric morphometrics, bandpass filtering of partial warp …

Darwin’s finches habitually anoint their feathers with leaves of the endemic tree Psidium galapageium during the non-breeding season

Birds host a wide range of ectoparasites and have developed behavioural strategies to combat them, such as preening, dust bathing and water bathing. In addition, a wide range of avian taxa anoint their feathers with insects or plants that have …

Sex differences in the pelvis did not evolve de novo in modern humans

It is commonly assumed that the strong sexual dimorphism of the human pelvis evolved for delivering the relatively large human foetuses. Here we compare pelvic sex differences across modern humans and chimpanzees using a comprehensive geo- metric …

Allometry and sexual dimorphism in the human pelvis

Sexual dimorphism in the human pelvis has evolved in response to several jointly acting selection regimes that result from the pelvis’ multiple roles in locomotion and childbirth, among others. Because human males are, on average, taller than …

Reply to Grossman: The role of natural selection for the increase of Caesarean section rates

Recently, we presented the “cliff-edge model” (1) to explain why natural selection has not reduced the high rates of fetopelvic disproportion (FPD) in childbirth. This evolutionary model predicts that birth-relevant anatomical dimensions have changed …

Cliff-edge model of obstetric selection in humans

The strikingly high incidence of obstructed labor due to the disproportion of fetal size and the mother’s pelvic dimensions has puzzled evolutionary scientists for decades. Here we propose that these high rates are a direct consequence of the …

Adult pelvic shape change is an evolutionary side effect

In their interesting article, Huseynov et al. (1) propose the “developmental obstetric dilemma (DOD) hypothesis,” which posits that human pelvic morphology reflects the changing obstetric needs during a female’s lifetime. In particular, the authors …

Lateral plate number in low‐plated threespine stickleback - a study of plasticity and heritability