  We propose a simple stochastic model which successfully explains the long
coherence effects observed in photosynthetic Excitation Energy Transport (EET)
by 2D photon echo experiments of G. S. Engel et. al. (Nature, {\bf 446} 782,
(2007)). Our Two-Component Phonon Spectrum (TCPS) model is based upon the
division of phonon degrees of freedom into a systematic component which is
treated through polaron transformation and a stochastic component which is
treated through dynamical disorder. This model successfully explains the
observed long coherence upto $ \sim 600 fsec$ in EET experiments.
