om es ▁for ▁de grad ation . ▁  ▁Vari ous ▁gen etic ▁tools , ▁protocol s , ▁and ▁ass ays ▁make ▁D ros oph ila ▁favor able ▁for ▁studying ▁the ▁inn ate ▁imm une ▁system . ▁ ▁Be havior al ▁gen et ics ▁and ▁neu ros cience ▁ ▁In ▁ 1 9 7 1 , ▁Ron ▁Kon op ka ▁and ▁Se ym our ▁Ben zer ▁published ▁" C lock ▁mut ants ▁of ▁D ros oph ila ▁mel an og aster ", ▁a ▁paper ▁describing ▁the ▁first ▁mut ations ▁that ▁affected ▁an ▁animal ' s ▁behavior . ▁Wild - type ▁f lies ▁show ▁an ▁activity ▁rh ythm ▁with ▁a ▁frequency ▁of ▁about ▁a ▁day ▁( 2 4 ▁hours ). ▁They ▁found ▁mut ants ▁with ▁faster ▁and ▁slower ▁rh yth ms , ▁as ▁well ▁as ▁broken ▁rh yth ms — f lies ▁that ▁move ▁and ▁rest ▁in ▁random ▁sp ur ts . ▁Work ▁over ▁the ▁following ▁ 3 0 ▁years ▁has ▁shown ▁that ▁these ▁mut ations ▁( and ▁others ▁like ▁them ) ▁affect ▁a ▁group ▁of ▁gen es ▁and ▁their ▁products ▁that ▁form ▁a ▁bio chem ical ▁or ▁bi ological ▁clock . ▁This ▁clock ▁is ▁found ▁in ▁a ▁wide ▁range ▁of ▁fly ▁cells , ▁but ▁the ▁clock - b ear ing ▁cells ▁that ▁control ▁activity ▁are ▁several ▁dozen ▁neur ons ▁in ▁the ▁fly ' s ▁central ▁brain . ▁ ▁Since ▁then , ▁Ben zer ▁and ▁others ▁have ▁used ▁behavior al ▁screens ▁to ▁isol ate ▁gen es ▁involved ▁in ▁vision , ▁ol f action , ▁aud