Improving Human Anatomy
In that work I was looking about how the age affect the body shapes. I focused in head because is the main source of info when we look to someone. Wrinkles flow is a very good point to focus, understand why and where they appear is quite relevant. Of course, the most important is get a good photo reference before start sculpting.
In reference to ethnicities I was looking for differences between Caucasian, Asian and African people. You can see here some picks of the work.