Cues to fertility: perceived attractiveness and facial shape predict reproductive success

Attractive facial features in women are assumed to signal fertility, but whether facial attractiveness predicts reproductive success in women is still a matter of debate. We investigated the association between facial attractiveness at young adulthood and reproductive life history—number of children and pregnancies—in women of a rural community. For the analysis of reproductive success, we divided the sample into women who used contraceptives and women who did not. Introducing two-dimensional geometric morphometric methodology, we analysed which specific characteristics in facial shape drive the assessment of attractiveness and covary with lifetime reproductive success. A set of 93 (semi)landmarks was digitized as two-dimensional coordinates in postmenopausal faces. We calculated the degree of fluctuating asymmetry and regressed facial shape on facial attractiveness at youth and reproductive success. Among women who never used hormonal contraceptives, we found attractive women to have more biological offspring than less attractive women. These findings are not affected by sociodemographic variables. Postmenopausal faces corresponding to high reproductive success show more feminine features—facial characteristics previously assumed to be honest cues to fertility. Our findings support the notion that facial attractiveness at the age of mate choice predicts reproductive success and that facial attractiveness is based on facial characteristics, which seem to remain stable until postmenopausal age.     

The pathogenicity of the Pro1148Ala substitution in the FBN1 gene: causing or predisposing to Marfan syndrome and aortic aneurysm, or clinically innocent?

In individuals with the Marfan syndrome (MFS), mutations have been identified in the fibrillin-1 gene (FBN1) at 15q21.1. A proline-to-alanine change at position 1148 in exon 27 (Pro1148Ala) has been reported in probands with MFS, aortic aneurysm or Marfanoid-craniosynostosis. It was suggested that this mutation could be a risk factor for aortic dilatation, since it was rarely observed in control populations. To investigate further the pathogenicity of this substitution, we screened 416 unrelated control individuals by allele-specific oligonucleotide (ASO) hybridization. We found 16 individuals who carried the alanine allele (3.8%), 3 of whom were homozygous. Five were of Latin American and eight were of Asian extraction. We also screened 133 probands with MFS, aortic aneurysm or related connective tissue disorders and found 4 (3%) that were heterozygous for the 1148Ala allele. All positive results were confirmed by DNA sequencing. In 20 individuals with 1148Ala, we confirmed the association with the rarer A allele at the IVS27-5G→A polymorphism. Our results suggest that the Pro1148Ala change is a polymorphism of ancient evolutionary origin that is more prevalent in Asian and Latin American than in Caucasian or African populations. Received: 4 October 1996 / Revised: 3 December 1996     

Post-Amputation Pain Is Associated with the Recall of an Impaired Body Representation in Dreams—Results from a Nation-Wide Survey on Limb Amputees

The experience of post-amputation pain such as phantom limb pain (PLP) and residual limb pain (RLP), is a common consequence of limb amputation, and its presence has negative effects on a person’s well-being. The continuity hypothesis of dreams suggests that the presence of such aversive experiences in the waking state should be reflected in dream content, with the recalled body representation reflecting a cognitive proxy of negative impact. In the present study, we epidemiologically assessed the presence of post-amputation pain and other amputation-related information as well as recalled body representation in dreams in a sample of 3,234 unilateral limb amputees. Data on the site and time of amputation, residual limb length, prosthesis use, lifetime prevalence of mental disorders, presence of post-amputation pain, and presence of non-painful phantom phenomena were included in logistic regression analyses using recalled body representation in dreams (impaired, intact, no memory) as dependent variable. The effects of age, sex, and frequency of dream recall were controlled for. About 22% of the subjects indicated that they were not able to remember their body representation in dreams, another 24% of the amputees recalled themselves as always intact, and only a minority of less than 3% recalled themselves as always impaired. Almost 35% of the amputees dreamed of themselves in a mixed fashion. We found that lower-limb amputation as well as the presence of PLP and RLP was positively associated with the recall of an impaired body representation in dreams. The presence of non-painful phantom phenomena, however, had no influence. These results complement previous findings and indicate complex interactions of physical body appearance and mental body representation, probably modulated by distress in the waking state. The findings are discussed against the background of alterations in cognitive processes after amputation and hypotheses suggesting an innate body model.     

Structural and Functional Evolution of the Trace Amine-Associated Receptors TAAR3, TAAR4 and TAAR5 in Primates

The family of trace amine-associated receptors (TAAR) comprises 9 mammalian TAAR subtypes, with intact gene and pseudogene numbers differing considerably even between closely related species. To date the best characterized subtype is TAAR1, which activates the G_s protein/adenylyl cyclase pathway upon stimulation by trace amines and psychoactive substances like MDMA or LSD. Recently, chemosensory function involving recognition of volatile amines was proposed for murine TAAR3, TAAR4 and TAAR5. Humans can smell volatile amines despite carrying open reading frame (ORF) disruptions in TAAR3 and TAAR4. Therefore, we set out to study the functional and structural evolution of these genes with a special focus on primates. Functional analyses showed that ligands activating the murine TAAR3, TAAR4 and TAAR5 do not activate intact primate and mammalian orthologs, although they evolve under purifying selection and hence must be functional. We also find little evidence for positive selection that could explain the functional differences between mouse and other mammals. Our findings rather suggest that the previously identified volatile amine TAAR3–5 agonists reflect the high agonist promiscuity of TAAR, and that the ligands driving purifying selection of these TAAR in mouse and other mammals still await discovery. More generally, our study points out how analyses in an evolutionary context can help to interpret functional data generated in single species.