The concept of a biological species as a group of organisms capable of interbreeding to produce viable offspring dates back to at least the 18th century, although it is often associated today with Ernst Mayr. Species of the fruit-fly<unk>  are one of the most commonly used organisms in evolutionary research, and have been used to test many theories related to the evolution of species. The genus<unk>  comprises numerous species that have varying degrees of premating and postmating isolation (including<unk><unk>  between them. These species are useful for testing hypotheses of the reproductive mechanisms underlying speciation.
Drosophila hybrid sterility
XY gonadal dysgenesis
XX male syndrome
Triploid syndrome
Gonadal dysgenesis
Thyroid dysgenesis
XX gonadal dysgenesis
X-linked intellectual disability