so many species, evolution seems to favor male aggression, especially
in the behaviors around reproduction. But in the egg warming
phase of emperor penguin reproduction, all the guys with eggs
on their feet [love writing that] shuffle around so that everyone
gets a chance to the warmer inner circle.
At some point in their story there must have been regular guy
penguins who tried holding on to the warm inner spot rather
than shuffle along. With or without more than one macho 'guin,
the ensuing jostling would have broken eggs on the feet of macho
guy and otherwise innocent bystanders. [I believe the phrase
originates in this context.] So the reproductive edge here favors
cooperative males, a nice change of pace from the usual grunt
and growl, and so perfectly suited to the penguins' charisma.
Katz • Prof. of law SUNY, Buffalo, 1969-1989 (ret.)