It is reported that scientists are finding that parthenogenesis (asexual or 'virgin birth') is more common amongst vertebrates (rather than just greenfly) than was previously realised (http://www.theguardian.com/science/2015/jun/01/sawfish-escape-extinction-through-virgin-births-scientists-discover). The phenomenon has been known to occur in certain captive (in aquaria or zoos) species of fish and reptiles. It has now also been shown to take place in wild species where it may serve to maintain populations when numbers become very small (other species can show spontaneous sex change apparently for the same purpose?) as in a 'bottleneck' situations. Although parthenogenesis would reduce genetic diversity, it may be essential in emergency situations where extinction is the alternative. One of the lines of evidence includes the Florida Smalltooth sawfish where a genetic study revealed that 3% of these overfished (numbers are currently down to 1% of those evident in 1900) animals were the result of eggs being fertilised by the mother's own cells.
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