Apomixis is a unique reproductive process that produces fertile offspring without the combination of sperm and egg cells. This perfectly reproduces maternal DNA, making it possible to fix heterosis during reproduction. Malus shizongensis newly discovered species closely related hupehensis Rehd. After de-male bagging, was found fruit set rate reached 78.7%. Preliminary analysis indicated M. have...

The evolutionary constraints that lead to the evolution of sexual reproduction are framed by the better repair mechanisms that repair fatal mutations, as well as the need for variable immune systems imposed on large organisms by parasites, such as viruses and bacteria. Besides the evolution of sexual reproduction, these factors also affect mate choice, especially as regards the gene complex tha...

Clonality is a pervasive feature of sessile organisms, but this form of asexual reproduction is thought to interfere with sexual fitness via the movement of gametes among the modules that comprise the clone. This within-clone movement of gametes is expected to reduce sexual fitness via mate limitation of male reproductive success and, in some cases, via the production of highly inbred (i.e., se...

Syngnathid fishes (pipefishes, seahorses and seadragons) are characterized by a unique mode of paternal care in which embryos develop on or in the male's body, often within a structure known as a brood pouch. Evidence suggests that this pouch plays a role in mediating postcopulatory sexual selection and that males have some control over the events occurring within the pouch during the pregnancy...

In Daphnia (Cladocera, Crustacea), parthenogenetic reproduction alternates with sexual reproduction. Individuals of both sexes that belong to the same parthenogenetic line are genetically identical, and their sex is determined by the environment. Previously, non-male producing (NMP) genotypes have been described in species of the Daphnia pulex group. Such genotypes can only persist through phas...

Sib matings increase homozygosity and, hence, the frequency of detrimental phenotypes caused by recessive deleterious alleles. However, many species have evolved adaptations that prevent the genetic costs associated with inbreeding. We discovered that the highly invasive longhorn crazy ant, Paratrechina longicornis, has evolved an unusual mode of reproduction whereby sib mating does not result ...

The evolution of sexual reproduction remains a fascinating enigma in biology. Theoretically, populations of sexual organisms investing half of their resources into producing male offspring that don't contribute to reproduction should grow at only half the rate of their asexual counterparts. This demographic disadvantage due to male production is known as the twofold cost of sex. However, the qu...

Deoxyribonucleic Acid or DNA is commonly known to be responsible for encoding the information of life. Through sexual reproduction, DNA is passed on as hereditary material to offspring. During the replication of genes to be passed on to the offspring, sometimes ‘mistakes’ might occur. These mistakes cause the DNA, instead of being identical to the parent DNA, to change a little(one or more of t...

Sexual selection involves two main mechanisms: intrasexual competition for mates and intersexual mate choice. We experimentally separated intrasexual (male-male interference competition) and intersexual (female choice) components of sexual selection in a freshwater fish, the European bitterling (Rhodeus sericeus). We compared the roles of multiple morphological and behavioural traits in male su...