Allergic host defences
Noah W. Palm, Rachel K. Rosenstein & Ruslan Medzhitov
Nature 484;465–472 (26 April 2012)

QuoteAllergies are generally thought to be a detrimental outcome of a mistargeted immune response that evolved to provide immunity to macroparasites. Here we present arguments to suggest that allergic immunity has an important role in host defence against noxious environmental substances, including venoms, haematophagous fluids, environmental xenobiotics and irritants. We argue that appropriately targeted allergic reactions are beneficial, although they can become detrimental when excessive. Furthermore, we suggest that allergic hypersensitivity evolved to elicit anticipatory responses and to promote avoidance of suboptimal environments.

Interesting premise-- not 'huge' news, per se, since (as noted in the abstract) this is along the lines of what immunologists and evolutionary biochemists have thought all along... but still, VERY nice to see some research in this direction.  Atopy is very clearly epigenetic, and that means that there has to have been some evolutionary advantage conferred by having this genetic potential.  Like sickle-cell diseases conferring resistance to malarial illness.  Particularly nice to see this running in a flagship journal.

http://www.nature.com/nature/journal/v484/n7395/full/nature11047.html

DH forwarded this to me. You'll need purchase access to get the article in full. I'm posting on my phone with kids pulling at me so I can't successfully copy the abstract here.