Previous explanations for the difference have created their own puzzles. (newscientist.com)
Previous explanations of female mimicry in various animal species have regarded it as an alternative mating strategy, in which impersonators may steal matings or avoid aggression from brawnier rival males. (scientificamerican.com)
Previous explanations suggested that the stars that form the bulge are in banana - like orbits, but a paper published this week in Monthly Notices of the Royal Astronomical Society suggests that the stars probably move in peanut - shell or figure of eight - shaped orbits instead. (sciencedaily.com)