parthenogenetic

Parthenogenesis refers to the development of an embryo from an unfertilized egg, producing offspring without fertilization by a male. The term parthenogenetic is used to describe organisms that reproduce in this way, either as their normal mode of reproduction or as a rare or facultative alternative.

In animals, parthenogenesis can occur through different genetic routes. Automixis involves meiosis followed by the fusion of gamete products to restore diploidy, often yielding offspring with high homozygosity. Apomixis (in a broader sense) denotes development without meiosis, producing genetically identical offspring. In plants, a form of parthenogenesis called apomixis is widespread and is a common mechanism of seed formation that bypasses fertilization, enabling clonal reproduction.

Parthenogenesis has been observed in a variety of invertebrate groups, including rotifers, nematodes, aphids and some crustaceans and arachnids. In vertebrates, it occurs in a small but notable number of species: several reptiles, notably many whiptail lizards, are obligate parthenogens; there have been documented cases in other reptiles such as the Komodo dragon, and occasional reports in some sharks. Parthenogenetic offspring may be viable but often exhibit reduced genetic diversity due to propagation of a single maternal genome, and can be sterile or have limited fertility in some lineages. In species that are all-female, offspring are typically clones of the mother.

Ethical and practical considerations arise in fertility research, cloning, and conservation biology, where parthenogenesis can affect population genetics and management strategies.