We attempt to answer why sex is nearly ubiquitous when asexual reproduction is ostensibly more efficient than sexual reproduction. From the perspective of a genetic allele, each individual bearing that allele is akin to a stock share yielding dividends equal to that individual’s number of offspring, and the totality of individuals bearing the allele is its portfolio investment. Alleles compete ...

The dominance of sexual reproduction is still an unresolved enigma in evolutionary biology. Strong advantages of sex have to exist, because only a few parthenogenetic taxa persist over evolutionary timescales. Oribatid mites (Acari) include outstanding exceptions to the rule that parthenogenetically reproducing taxa are of recent origin and doomed to extinction. In addition to the existence of ...

In fungi, unisexual reproduction, where sexual development is initiated without the presence of two compatible mating type alleles, has been observed in several species that can also undergo traditional bisexual reproduction, including the important human fungal pathogens Cryptococcus neoformans and Candida albicans. While unisexual reproduction has been well characterized qualitatively, detail...

Cinsel eğitim yaşamın başlangıcından itibaren sağlıklı gelişim sürecinde etkili olan bir kavramdır. İnsan bedeni ve gelişimi, şiddetten korunma güvende olma gibi üreme konusu da cinsel eğitimin parçasıdır. Bu araştırmada çocukların konusuna yönelik sorularına yanıt verebilecek nitelikte, amaçlı örnekleme yoluyla belirlenen 11 resimli çocuk kitabı oluşturulan temalar çerçevesinde incelenmiştir. ...

This study was carried out to determine population structure, growth and reproduction properties of barbel. A total of 198 individuals were sampled. Ages of samples were found between I and VI years, fork lengths between 4.3 and 16.6 cm and total weights between 1.2 and 65.8 g. Length-weight relationship was calculated as W=0.0146×L2.934. Munro’s phi prime index was estimated as 1.95, L∞ ...