Friday, October 10, 2008

Shark Virgin Births and Anthropology

Scientists have now confirmed a second shark virgin birth. In a study reported today in the Journal of Fish Biology, researchers report genetic analysis demonstrating that a blacktip pup had no father (no DNA from a male shark). (h/t Wired)

This is the second example of parthenogenesis (development of an egg without fertilization) observed in sharks. Parthenogenesis is common in plants and invertebrates. It is much more rare among vertebrates, though is well-documented in reptiles and fish and some birds.

Human beings have long been fascinated with the concept of virgin birth. Mythology and human history contain many reported instances. Most well-known, of course, is the birth of Jesus Christ, the founder of Christianity. Here is a partial list of other figures reportedly born of virgins: the Egyptian sun god Ra, Hindu god Krishna, Iranian prophet Zoroaster, Greek king Alexander the Great, Greek god Dionysus, Mongol emperor Genghis Khan, Chinese mythic philosopher Lao-Tzu and the Buddha. See wikipedia for a full list and distinction between virgin and miraculous births.

Parthenogenesis nearly always results in females in species where the Y chromosome determines sex (as in humans). Of note, human records of virgin birth generally involve a male child. (back)

(image credit: blacktip shark, AP/Institute for Ocean Conservation Science/Matthew D. Potenski, wired.com)