When faced with a question about a capital crime, do we follow rov – the majority – or not? This question is debated in our Gemara, where Ravina believes that it is obvious that we follow rov – after all, if witnesses differ in their description of an incident by a single day on the calendar, we accept their testimony, following the dictum that most people are not aware of the exact day that the new moon was declared. Rav Huna the son of Rav Yehoshua disagrees, arguing that the biblical passages requiring the Jewish court to do its utmost to find the accused innocent (see 35:24-25) prove that we will not follow the rov in such cases.
Rabbi Yirmeya of Difti tries to support Ravina’s ruling by quoting a baraita that teaches that a girl who gets married years before reaching physical maturity will be considered married for all purposes. We assume this to be true, even though a minority of girls will be found to be in the category of ailonit whose maturity will be delayed, and whose marriage may be annulled. Ultimately the Gemara suggests that the baraita may only be referring to cases where the husband clearly accepts this woman as his wife, even if she is an ailonit.
From the detailed discussions in the Gemara – mainly in Massekhet Yevamot – it appears that an ailonit suffers from a genetic defect that does not allow her to have children. This is a different categorization than an akara – a barren woman – whose physical and sexual development is ordinarily normal, but cannot have children because of some other deficiency or impediment. From those descriptions it appears that an ailonit can be recognized by certain unique physical traits, including a lack of secondary sex characteristics, like pubic hairs. Furthermore, it appears from the Gemara that there are different types of ailonit, ranging from women who have an overabundance of male hormones to those who suffer from Turner syndrome, where only one X chromosome is present and fully functioning. Approximately 98% of all fetuses with Turner syndrome spontaneously abort; the incidence of Turner syndrome in live female births is believed to be about 1 in 2500.
Within Jewish law there are many discussions about the status of an ailonit, mainly because of the lack of secondary female sex characteristics and because they develop at a relatively advanced age. Thus we find questions about when an ailonit is considered to have reached the age of adulthood, which halakha ordinarily defines as physical maturity.