▁Ron ald ▁Fish er ' s ▁Ge ometric ▁Model ▁in ▁ 1 9 3 0 . ▁This ▁mathematical ▁model ▁illustr ates ▁how ▁evolution ary ▁fit ness ▁depends ▁on ▁the ▁independence ▁of ▁phen ot yp ic ▁variation ▁from ▁random ▁changes ▁( that ▁is , ▁mut ations ). ▁It ▁the or izes ▁that ▁an ▁increasing ▁phen ot yp ic ▁independence ▁corresponds ▁to ▁a ▁decrease ▁in ▁the ▁lik elihood ▁that ▁a ▁given ▁mut ation ▁will ▁result ▁in ▁an ▁increase ▁in ▁fit ness . ▁Exp and ing ▁on ▁Fish er ' s ▁work , ▁S ew all ▁Wright ▁provided ▁more ▁evidence ▁in ▁his ▁ 1 9 6 8 ▁book ▁E volution ▁and ▁the ▁Gen et ics ▁of ▁Pop ulations : ▁Gen etic ▁and ▁Bi ometric ▁Found ations ▁by ▁using ▁mole cular ▁gen et ics ▁to ▁support ▁the ▁idea ▁of ▁" univers al ▁ple iot ropy ". ▁The ▁concepts ▁of ▁these ▁various ▁studies ▁on ▁evolution ▁have ▁seed ed ▁numerous ▁other ▁research ▁projects ▁rel ating ▁to ▁individual ▁fit ness . ▁ ▁In ▁ 1 9 5 7 ▁evolution ary ▁bi ologist ▁George ▁C . ▁Williams ▁the or ized ▁that ▁ant agon istic ▁effects ▁will ▁be ▁exhib ited ▁during ▁an ▁organ ism ' s ▁life ▁cycle ▁if ▁it ▁is ▁closely ▁linked ▁and ▁ple iot rop ic . ▁Natural ▁selection ▁fav ors ▁gen es ▁that ▁are ▁more ▁benef icial ▁prior ▁to ▁reprodu ction ▁than ▁after ▁( leading ▁to ▁an ▁increase ▁in ▁re product ive ▁success ). ▁Know ing ▁this , ▁Williams ▁argued ▁that ▁if ▁only ▁close ▁link age ▁was ▁present ,