Mark Jobling, a welcome trust senior research fellow, and professor of genetics at Leicester University, presents a series of short commentaries published in Investigative Genetics every two months. His column provides a thoughtful discussion of the world of genetics, across a varied  range of topics- reflecting the wide scope of the journal.

In this month’s ‘Mark my words’ column, Mark struggles with finding an appropriately seasonal topic on which to discuss the topic of genetics. His pondering of the possible topics suggested by PubMed provides him with little inspiration, as articles brought up are almost satirical in their discussions of the dangers of the Christmas period and all things festive.

His musings on possible Christmas wish-lists, and the overwhelmingly Apple dominated world of electronics lead him to hit upon a topic which he was asked to discuss at a decidedly Apple-free Café Scientifique- where technology such as powerpoints is not encouraged in presentations. And so, Mark has found an equally Christmassy and genetically relevant topic of virgin birth- or parthenogenesis.

Parthenogenesis is not an uncommon form of reproduction among certain members of the animal kingdom, and indeed provides the greatest genetic pay-off for the investment of resources by the mother-from a selfish perspective. However, as Mark points out, the high price of asexual reproduction in the form of genetic uniformity (and therefore increased susceptibility to pathogens) can explain why sexual reproduction is almost uniform- with many asexual species being transient. Using an example of a child who was thought to be of parthenogenetic origin (but in fact turned out to be a chimaera) Mark demonstrates that, for humans at least, this mode of reproduction is not viable- even at Christmas. So, Mark’s discussion leads us to conclude that a virgin-birth would indeed be a miracle!