Inbiology, evolutioncanbedefinedasanychangeintheheritabletraits (thosearephysicaltraitslikefurcolorinmice, spotsonthewingsofbutterfliesorinstinctivebehaviorslikethewaythatdogsgreettheirfriendswith a sniff,) within a populationacrossgenerations.
Thisdefinitioncanbe a bitconfusing, solet's seehowitworks.
Thesemutations, whichhappencompletelyonaccidentandrandomlytoanypartof a DNAstrand, canproducevariationinthebodyshapeandfunctionofthecreaturewhoinheritsthemodifiedDNA.
Evolution, anychangeintheheritabletraitswithin a populationacrossgenerations, hasofficiallyoccurred.
Reproductionfordolphinsandbadgersandpeopleis a littlemorecomplicated.
Wehavetofindourselves a partner.
Whentwo a badgersgettogetherandyouknow... fallinlove, a spermcellfromthefatherwhichcontains a copyofhalfofhisDNA, onlyhalf, combineswiththeeggcellofthemother, whichcontainshalf a copyofherDNA.
Theresultis a brandnewcellwith a completesetofDNAinstructions – alltheinformationneededtodivideandgrowupinto a brandnewbadger.
Thenewchildmaturestobesimilartoherparentsbutalsounique, becauseshedevelopedsometraitsfrom a mother's DNAandsomefromherfather.