Those women all have women's bodies as adults, but they are also smaller than the average adult woman, especially Kwan and Wagner who are on the shorter side of average.
The statistics would look very different if you look at all elite skaters who competed as seniors internationally, or nationally in countries where skating as popular, vs. looking at all skaters who start training early and master jumps up to double lutz, to see how many of the latter group ever land a clean double axel or triple jump let alone reach elite levels or keep those jumps by age 18 or 20.
This.
Any sport is going to self-select for some sort of biological qualities that gives its athletes an advantage. Sure, Michael Phelps trains his butt off, but his body is also just crazy:
http://gawker.com/5038018/michael-phelps-freakish-physique-explained
If you were to pick and choose genetics for the perfect human swimmer, it would look like Michael Phelps.
We aren't going to see any 6-foot tall ladies winning Olympic medals in figure skating.
Weight, of course, is much more complicated than the majority of other aspects of the human body, in that it is partly biological and partly due to lifestyle choices. If you're genetically-predisposed to being overweight (but nothing as dramatic as, say, a glandular problem or something), diet and exercise will keep you fit and trim. But you're going to have to work harder than someone genetically pre-disposed to being thin, and the person who is genetically pre-disposed to being thin, if they make the same healthy lifestyle choices you do, will probably have an advantage over you in sports where smaller is better.
It's even more complicated in a sport like figure skating, where pre-pubescent bodies happen to be better built for certain elements. Then once a person begins growing into whatever their genes decide they're going to be, there are going to be problems.
It does make one think that maybe senior competition should start at 18. Rather than allowing the sport to self-select its best candidates after they've already been presented to the entire world as one of the best of the best (like Yulia in Sochi), let them figure out as juniors, when the stakes are lower, whether or not they should or could make a career out of figure skating, based in part on what their bodies are telling them.
If Yulia had not been able to skate at the senior level until she was 18, it's possible she would've quit the sport at 16 or 17 when her jumps began to fail her, decided it wasn't worth it. She would've picked up other hobbies, focused on something else, and maybe even still love figure skating as a fun hobby instead of a career. She wouldn't have had the Sochi success, or faced the pressure, or become an international superstar. But she might also be a much happier and healthier human being.
(I really got going on a tangent there.)
