Johnathan, Nice one! :-) As far as I can see there is nothing a-priori which would make these two hypotheses mutually exclusive; one 'cause' is predator related, the other is resource related.
I await with interest, but not bated breath, for an ecologist to tell us of any empirical evidence supporting or refuting either. Of equal interest is the question of how the creatures keep count of the passing years and 'know' when their species's lucky number has come up! Presumably *something* grows a bit with each passing year and reaches a threshold size/shape/consentration at the right time. Alternatively something is formed in the first year, which could be the overall size/volume of the grub or the total amount of stored energy, and this thing or substance decreases with each passing year so that emergence is triggered by that key feature or substance reaching its minimum amount needed for survival in the next life stage. Upon reflection I think the latter mechanism is more likely. I can see more easily how it could evolve from a system under a selfective pressure which extended the dormancy period but originally allowed a significant spread of the dormancy period over several years. Cheers, Mark --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to firstname.lastname@example.org To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~----------~----~----~----~------~----~------~--~---