An avunculate marriage is any marriage between an uncle/aunt and a niece/nephew. It may refer to a marriage between biological relatives or people related by marriage. In some countries, avunculate marriages are prohibited by law, while in others marriages between biological relatives of this kind are both legal and common.
If the partners in an avunculate marriage are biologically related, they normally have the same genetic relationship as half-siblings, or a grandparent and grandchild – that is they share approximately 25% of their genetic material. (They are therefore more closely related than partners in a marriage between first cousins, in which on average the members share 12.5% of inherited genetic material, but less than that of a marriage between, for instance, cousin-siblings, in which the partners share 37.5% of their inherited genetic material.)
Avunculate marriage is legal in Argentina, Australia,, Brazil, Finland, Malaysia, The Netherlands, and Russia. It is explicitly illegal in most English-speaking countries.
View More On Wikipedia.org