Inspired by Daniels interest in fat distribution: Why are boobs 95% fat and only 5% milk making tissue? ——— Because the form factor has been sexually selected. Why it has been evolutionarily successful to mate with females that have a certain boob morphology rather than others is still speculation. You would think that nice fat boobs would be correlated with some fitness factor, just like we are attracted to pure skin and lush hair since those traits are correlated with youth and good health. But it might just be a quirk that exploits some other human evaluative disposition.