 In its original broadcast , " Survival of the Fittest " received a Nielsen rating of 1 @.@ 2 / 3 , which is considered high for American television . The rating was the top mark for the 10 : 00 a.m. timeslot for the 2007 @-@ 2008 season and was a 20 % increase of the previous week 's . In key kids 2 @-@ 11 , it received a rating of 1 @.@ 4 / 5 , a 25 % increase from the previous week 's mark in the demographic . 
