▁become ▁en rich ed ▁in ▁carbon - 1 3 ▁compared ▁to ▁non ▁sym b ion t - b ear ing ▁cal care ous ▁organ isms . ▁If ▁foss il ▁evidence ▁can ▁be ▁gathered ▁for ▁is ot op ic ▁ratio ▁analysis , ▁the ▁time ▁window ▁for ▁appearance ▁of ▁alg al ▁sym b ion ts ▁with ▁n ass ell ari ans ▁and / or ▁sp um ell ari ans ▁should ▁be ▁able ▁to ▁be ▁restricted ▁in ▁ge olog ic ▁time . ▁ ▁References ▁ ▁Category : Pol yc yst ines ▁Category : Ret aria ▁orders <0x0A> </s> ▁D ry ▁ro ast ing ▁is ▁a ▁process ▁by ▁which ▁heat ▁is ▁applied ▁to ▁dry ▁food st uff s ▁without ▁the ▁use ▁of ▁oil ▁or ▁water ▁as ▁a ▁car rier . ▁Un like ▁other ▁dry ▁heat ▁methods , ▁dry ▁ro ast ing ▁is ▁used ▁with ▁food s ▁such ▁as ▁n uts ▁and ▁se eds , ▁in ▁addition ▁to ▁some ▁e aten ▁insect s ▁such ▁as ▁house ▁cr ick ets . ▁D ry - ro asted ▁food s ▁are ▁stir red ▁as ▁they ▁are ▁ro asted ▁to ▁ensure ▁even ▁he ating . ▁ ▁D ry ▁ro ast ing ▁can ▁be ▁done ▁in ▁a ▁f ry ing ▁pan ▁or ▁w ok ▁( a ▁common ▁way ▁to ▁prepare ▁sp ices ▁in ▁some ▁cu is ines ), ▁or ▁in ▁a ▁special ized ▁ro aster ▁( as ▁is ▁used ▁for ▁coffee ▁be ans ▁or ▁pe an uts ). ▁D ry ▁ro ast ing ▁changes ▁the ▁chem istry ▁of ▁prote ins ▁in ▁the ▁food