The typical breeding system of cladocerans, cyclic parthenogenesis, is poorly suited to polar settings because it requires one or more rounds of parthenogenesis before the production of males and sexual eggs. Past work has shown that many arctic cladocerans have secondarily made the transition to obligate, apomictic parthenogenesis. Arctic populations of Holopedium gibberum lack males, suggesti...

The near-ubiquity of sexual reproduction in animal species has long been considered a paradox because sexually reproducing individuals transmit only half of their genome to their progeny. Here, we show that the ant Cataglyphis cursor circumvents this cost by using alternative modes of reproduction for the production of reproductive and nonreproductive offspring. New queens are almost exclusivel...

Jacques Loeb [4] developed procedures to make embryos from unfertilized sea urchin [5] eggs in 1899. Loeb called the procedures ?artificial parthenogenesis," and he introduced them and his results in ?On the Nature of the Process of Fertilization and the Artificial Production of Norma Larvae (Plutei) from the Unfertilized Eggs of the Sea Urchin? in an 1899 issue of The American Journal of Physi...

Organisms that have ecologically similar sexual and asexual forms present an evolutionary puzzle, as theory predicts that eventually one form should eliminate the other. However, both forms may persist if there is niche partitioning between them. Geographical parthenogenesis is a hypothesis that predicts that in terms of niche use the asexual form in such pairs should be more ecologically succe...

Pristimantis reichlei is a widely distributed species, occurring in the Amazonian forests of Bolivia, Peru and Brazil. However, little information available on its natural history or breeding biology. Here we document for first time parental care clutch size this species. Parthenogenesis presumed.