Chapter 8 Evolution & Natural Selection flashcards _ Quizlet

3 itd o esn o tg iv ewh atasp eciesn eed s

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Unformatted text preview: p ed in th e p ast u n d er co n d itio n s th at d iffered fro m th o se in th e p resen t (lik e wh ale leg s) 2 .b o th th e p ro cess b y wh ich o rg an isms b eco me b etter match ed to th eir en v iro n men t an d to th e featu res o f an o rg an ism th at mak e it mo re in flu en ced b y h u man s. 3 . It d o es n o t g iv e wh at a sp ecies "n eed s" Artificial selectio n was u sed o n co rn to p ro d u ce a sin g le strain o f co rn with in creased g ro wth rates an d g reater resistan ce to a fu n g u s. Alth o u g h farmers h av e co n tin u ed to select fo r th ese traits, th e p ro d u ctiv ity o f th is strain is n o lo n g er in creasin g . Th is su g g ests th at: all o r mo st o f th e n atu ral v ariatio n fo r th ese traits h as b een elimin ated . In a p o p u latio n in wh ich a trait is ex p o sed to stab ilizin g selectio n o v er time: th e av erag e v alu e fo r th e traits stay s ap p ro x imately th e same an d th e v ariatio n fo r th e trait d ecreases. Maze­ru n n in g b eh av io r in rats: is a h eritab le trait. A fo ssil is d efin ed mo st b ro ad ly as: an y p reserv ed remo u n t o r trace o f an o rg an ism fro m th e p ast. In t...
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This document was uploaded on 02/25/2014.

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