January 2, 2012
To be posted on Nobabies.net

Nicole M. Gerlach
Department of Biology Indiana University-Bloomington
1001 East 3rd St
Bloomington, IN 47405-3700
812 855 1096

Dear Dr. Gerlach:
I see that NATURE journal having reviewed in September (Infidelity Yields Better Offspring NATURE vol. 477 no. 7364 September 15, 2011 page 252) your article in PROCEEDINGS OF THE ROYAL SOCIETY B (Promiscuous
mating produces offspring with higher lifetime fitness.Proc. R. Soc. B Http://dx.doi.org/10.1098/rspb.2011.1547(2011))  reviewed it again in November (Lawrence Bellamy and Andrew Pomiankoski NATURE vol. 479 no. 7372 November 10, 2011 page 184).  They certainly like you. 

Your point I take to be that dark-eyed junco birds frequently have offspring with mates that are not the ones they are socially bonded with and that these offspring are more successful on average in having offspring of their own than the offspring of within pair matings. 

I notice on your web site (http://www.indiana.edu/~kettlab/people/nicole/nicole_gerlach.html) the emphasis that this greater fitness of the extra-pair offspring is manifest during reproduction rather than in early life.  This did not make it into the review.

I also notice that you consider it possible that the effect could be due to better genes or to more compatible genes (emphasis mine).  Again, the reviewers did not pick up on this, but of course it is strongly suggested by the Iceland reference I sent in an earlier letter.  In other words the implication is that the females, having chosen a mate in haste during the bustle of mating season then with time may go find the more closely related males that the Iceland study indicates would produce the fittest offspring. 

That would require that they somehow can actually identify kin.  How they might do so is of course not clear, but given the powerful selective advantage of mating with the appropriate kin, such an ability should have evolved.

I am still hoping that your data set is detailed enough to go back and compare the kinship of the extra-pair mates with the kinship of the mates that have extra-pair eggs in their nests. 

Let me know what you think.  It would be nice when you answer to indicate wither you would like your reply posted on my web site or not.  Obviously it is of enormous interest but I will keep mum unless encouraged.


M. Linton Herbert

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