▁behavior , ▁phys i ology , ▁and ▁k ary ology , ▁may ▁be ▁expl ored . ▁For ▁example , ▁territorial ▁songs ▁are ▁indic ative ▁of ▁species ▁in ▁the ▁tre ec ree pers , ▁a ▁bird ▁genus ▁with ▁few ▁morph ological ▁differences . ▁M ating ▁tests ▁are ▁common ▁in ▁some ▁groups ▁such ▁as ▁fung i ▁to ▁confirm ▁the ▁re product ive ▁isol ation ▁of ▁two ▁species . ▁ ▁Analysis ▁of ▁DNA ▁sequences ▁is ▁becoming ▁increasing ly ▁standard ▁for ▁species ▁recognition ▁and ▁may , ▁in ▁many ▁cases , ▁be ▁the ▁only ▁useful ▁method . ▁D ifferent ▁methods ▁are ▁used ▁to ▁analy se ▁such ▁gen etic ▁data , ▁such ▁as ▁mole cular ▁ph y log en et ics ▁or ▁DNA ▁bar c oding . ▁Such ▁methods ▁have ▁greatly ▁contributed ▁to ▁the ▁discovery ▁of ▁crypt ic ▁species , ▁including ▁such ▁em blem atic ▁species ▁as ▁the ▁fly ▁ag ar ic ▁or ▁the ▁African ▁ele ph ants . ▁ ▁E volution ▁and ▁e col ogy ▁ ▁Spe ci ation ▁process ▁ ▁Species ▁forming ▁a ▁complex ▁have ▁typically ▁diver ged ▁very ▁recently ▁from ▁each ▁other , ▁which ▁sometimes ▁allows ▁the ▁ret rac ing ▁of ▁the ▁process ▁of ▁spe ci ation . ▁Species ▁with ▁differenti ated ▁populations , ▁such ▁as ▁ring ▁species , ▁are ▁sometimes ▁seen ▁as ▁an ▁example ▁of ▁early , ▁on going ▁spe ci ation : ▁a ▁species ▁complex ▁in ▁formation . ▁Nevertheless , ▁similar ▁but ▁distinct ▁species ▁have ▁sometimes ▁been ▁isolated ▁for ▁a ▁long ▁time ▁without ▁evol ving ▁differences , ▁a ▁phenomen on ▁known ▁as ▁" m