Intersex biology may include, for example, ambiguous-looking external genitalia, karyotypes that include mixed XX and XY chromosome pairs (46XX/46XY, 46XX/47XXY or 45X/XY mosaic).Clinically, medicine currently describes intersex people as having disorders of sex development, a term vigorously contested.
which states that if an individual of a certain sex could significantly increase its reproductive success after reaching a certain size, it would be to their advantage to switch to that sex.
This language has fallen out of favor due to misconceptions and pejorative connotations associated with the terms, and also a shift to nomenclature based on genetics.
Intersex is in some caused by unusual sex hormones; the unusual hormones may be caused by an atypical set of sex chromosomes.
The word intersex has come into preferred usage for humans, since the word hermaphrodite is considered to be misleading and stigmatizing,, which estimated the number, 65,000, used an estimated total number of animal species, 1,211,577 from "Classification phylogénétique du vivant (Vol. Most hermaphroditic species exhibit some degree of self-fertilization.
The distribution of self-fertilization rates among animals is similar to that of plants, suggesting that similar processes are operating to direct the evolution of selfing in animals and plants.