Offspring Production among the Extended Relatives of Samoan Men and Fa'afafine

Androphilia refers to sexual attraction to adult males, whereas gynephilia refers to sexual attraction to adult females. Male androphilia is an evolutionary paradox. Its development is at least partially influenced by genetic factors, yet male androphiles exhibit lower reproductive output, thus raising the question of how genetic factors underlying its development persist. The sexual antagonism hypothesis posits that the fitness costs associated with genetic factors underlying male androphilia are offset because these same factors lead to elevated reproduction on the part of the female relatives of androphilic males. Western samples drawn from low fertility populations have yielded inconsistent results when testing this hypothesis. Some studies documented elevated reproduction among the matrilineal female kin of androphilic males, whereas others found such effects in the paternal line. Samoa is a high-fertility population in which individuals reproduce closer to their maximum capacities. This study compared the reproductive output of the paternal and maternal line grandmothers, aunts, and uncles of 86 Samoan androphilic males, known locally as fa'afafine, and 86 Samoan gynephilic males. Reproductive output was elevated in the paternal and maternal line grandmothers, but not aunts or uncles, of fa'afafine. These findings are consistent with the sexual antagonism hypothesis and suggest that male androphilia is associated with elevated reproduction among extended relatives in both the maternal and paternal line. Discussion focuses on how this study, in conjunction with the broader literature, informs various models for the evolution of male androphilia via elevated reproduction on the part of female kin

Effect of Urea Solution on Haemonchus contortus Inoculum from Intact Faecal Pellets or L3 Larvae

Internal parasites cause severe economic losses to the sheep industry globally. Of particular concern is Haemonchus contortus; a parasite widely resistant to synthetic anthelmintics and prevalent in the warm wet environments of the tropics. The ovicidal and larvicidal properties of urea solution were investigated in pot trials using Batiki grass (Ischaemum aristatum var. indicum) inoculated with either intact faecal pellets containing approximately 10,000 eggs or 10,000 infective stage larvae. Urea solution at 5% concentration was sprayed once onto grass on the day of deposition for pellets and after a 48 hour adaptation period for infective stage larvae. Foliage and soil (inclusive of faecal pellets) were sampled separately for the presence of infective stage larvae. Urea significantly reduced larval populations from foliage for both pellet (P = 0.0015) and infective stage larvae (P = 0.0034) inoculums at P = 0.05. Urea did not significantly reduce larval populations from soil of pellet inoculated pots (P = 0.4055) but did from pots inoculated with infective stage larvae (P = 0.0488). Urea did not significantly reduce cumulative larval populations in pots inoculated with intact faecal pellets (P = 0.1070) but significantly reduced cumulative larval populations from pots inoculated with infective stage larvae (P = 0.0079). Urea solution at 5% is effective in reducing infective stage larvae from foliage. Application rate is a factor in its efficacy against Haemonchus contortus

Sequencing wild and cultivated cassava and related species reveals extensive interspecific hybridization and genetic diversity.

Cassava (Manihot esculenta) provides calories and nutrition for more than half a billion people. It was domesticated by native Amazonian peoples through cultivation of the wild progenitor M. esculenta ssp. flabellifolia and is now grown in tropical regions worldwide. Here we provide a high-quality genome assembly for cassava with improved contiguity, linkage, and completeness; almost 97% of genes are anchored to chromosomes. We find that paleotetraploidy in cassava is shared with the related rubber tree Hevea, providing a resource for comparative studies. We also sequence a global collection of 58 Manihot accessions, including cultivated and wild cassava accessions and related species such as Ceará or India rubber (M. glaziovii), and genotype 268 African cassava varieties. We find widespread interspecific admixture, and detect the genetic signature of past cassava breeding programs. As a clonally propagated crop, cassava is especially vulnerable to pathogens and abiotic stresses. This genomic resource will inform future genome-enabled breeding efforts to improve this staple crop