▁have ▁evol ved ▁to ▁have ▁l ighter ▁skin ▁in ▁order ▁to ▁help ▁their ▁bodies ▁abs orb ▁more ▁calci um . ▁ ▁The ▁Fitz pat rick ▁scale ▁is ▁a ▁numerical ▁classification ▁schema ▁for ▁human ▁skin ▁color ▁developed ▁in ▁ 1 9 7 5 ▁as ▁a ▁way ▁to ▁class ify ▁the ▁typical ▁response ▁of ▁different ▁types ▁of ▁skin ▁to ▁ult rav io let ▁( U V ) ▁light : ▁ ▁A ging ▁▁ ▁As ▁skin ▁ages , ▁it ▁becomes ▁th inner ▁and ▁more ▁easily ▁dam aged . ▁Int ens ifying ▁this ▁effect ▁is ▁the ▁decre asing ▁ability ▁of ▁skin ▁to ▁he al ▁itself ▁as ▁a ▁person ▁ages . ▁ ▁Among ▁other ▁things , ▁skin ▁ag ing ▁is ▁noted ▁by ▁a ▁decrease ▁in ▁volume ▁and ▁el astic ity . ▁There ▁are ▁many ▁internal ▁and ▁external ▁causes ▁to ▁skin ▁ag ing . ▁For ▁example , ▁ag ing ▁skin ▁receives ▁less ▁blood ▁flow ▁and ▁lower ▁g land ular ▁activity . ▁ ▁A ▁valid ated ▁compreh ensive ▁grad ing ▁scale ▁has ▁categor ized ▁the ▁clin ical ▁find ings ▁of ▁skin ▁ag ing ▁as ▁la x ity ▁( s ag ging ), ▁rh yt ids ▁( wr ink les ), ▁and ▁the ▁various ▁fac ets ▁of ▁photo aging , ▁including ▁er yth ema ▁( red ness ), ▁and ▁tel ang ie ct asia , ▁d ys p ig ment ation ▁( b rown ▁dis color ation ), ▁solar ▁el ast osis ▁( yellow ing ), ▁ker atos es ▁( ab normal ▁growth s ) ▁and ▁poor ▁texture . ▁ ▁Cort