Uncovering population structure in the Humboldt penguin (Spheniscus humboldti) along the Pacific coast at South America.

The upwelling hypothesis has been proposed to explain reduced or lack of population structure in seabird species specialized in food resources available at cold-water upwellings. However, population genetic structure may be challenging to detect in species with large population sizes, since variation in allele frequencies are more robust under genetic drift. High gene flow among populations, that can be constant or pulses of migration in a short period, may also decrease power of algorithms to detect genetic structure. Penguin species usually have large population sizes, high migratory ability but philopatric behavior, and recent investigations debate the existence of subtle population structure for some species not detected before. Previous study on Humboldt penguins found lack of population genetic structure for colonies of Punta San Juan and from South Chile. Here, we used mtDNA and nuclear markers (10 microsatellites and RAG1 intron) to evaluate population structure for 11 main breeding colonies of Humboldt penguins, covering the whole spatial distribution of this species. Although mtDNA failed to detect population structure, microsatellite loci and nuclear intron detected population structure along its latitudinal distribution. Microsatellite showed significant Rst values between most of pairwise locations (44 of 56 locations, Rst = 0.003 to 0.081) and 86% of individuals were assigned to their sampled colony, suggesting philopatry. STRUCTURE detected three main genetic clusters according to geographical locations: i) Peru; ii) North of Chile; and iii) Central-South of Chile. The Humboldt penguin shows signal population expansion after the Last Glacial Maximum (LGM), suggesting that the genetic structure of the species is a result of population dynamics and foraging colder water upwelling that favor gene flow and phylopatric rate. Our findings thus highlight that variable markers and wide sampling along the species distribution are crucial to better understand genetic population structure in animals with high dispersal ability.

Pica and Eating Attitudes: A Study of High-Risk Pregnancies.

OBJECTIVE: To describe and determine the association between the occurrence of pica and eating attitudes in women with high-risk pregnancies and to determine the prevalence of pica during pregnancy. METHODS: A cross-sectional and prospective 24-month study was conducted with 913 women with high-risk pregnancies. Structured interviews were carried out and the Eating Attitudes Test was applied. RESULTS: Pica was diagnosed in 5.7 % of the pregnant women, and its most commonly practiced type was geophagia (57.7 %). The association between pica and signs related to the eating attitudes: "to be considered too thin by others" (p < 0.02), and "to spend too much time thinking about food" (p = 0.05); and the association between pica and the risk of both anorexia nervosa and bulimia nervosa (p < 0.01) were statistically significant. CONCLUSIONS: The absence of validated instruments in the literature for assessing pica reinforces the difficulty of investigating this practice and the need for further studies. Moreover, additional efforts need to focus in the improvement of screening for other eating disorders with obstetric consequences associated with pica and be incorporated into the routine of healthcare professionals.