partenogenesis

Parthenogenesis is a form of asexual reproduction where an egg cell develops into an embryo without fertilization by sperm. This phenomenon occurs naturally in various species across the animal kingdom, including some insects, fish, reptiles, and even a few birds. The unfertilized egg can develop either spontaneously or due to certain environmental or artificial stimuli.

In many cases of parthenogenesis, the resulting offspring are genetically identical to the mother, essentially being clones. However, there are variations. In some species, a process similar to meiosis occurs, leading to genetic recombination, but without the fusion of gametes from two individuals. This can result in offspring that are not exact copies of the mother but are still developed from a single parent's egg.

Parthenogenesis can be obligate, meaning a species exclusively reproduces this way, or facultative, where individuals can reproduce both sexually and asexually depending on conditions. For instance, some rotifers and aphids reproduce parthenogenetically for rapid population growth when resources are abundant.

While rare in mammals, some studies have achieved experimental parthenogenesis in laboratory settings, though it has not been observed to occur naturally in this class of animals. The study of parthenogenesis provides insights into reproductive biology and the genetic mechanisms that govern development.