ABSTRACT
Study of evolutionary phenomenon is of great interest to biologists in discovering the secrets of life. The presence of reticulation events due to lateral gene transfer (LGT) among species poses new challenges for such evolutionary studies. In this paper an attempt has been made to develop an insilico model to predict LGT in the Rhodopseudomonas paulistris. Neighbour Joining method is employed to generate phylogenetic tree of 26 sequences of Alphaproteobacteria and one sequence of Cyanobacteria used as an out group. Then Least Squares approach is employed to predict the reticulation branches. Three reticulation branches were detected among these 27 sequences. The lateral gene transfer was predicted between Rhodopseudomonas paulistris 99 D and Rhodobacter sphaeroides, Rhodopseudomonas paulistris HMD 88 and Bradyrhizobium japonicum USDA and Bradyrhizobium japonicum USDA and Rhodobacter blasticus. The results obtained are in agreement with the results obtained by earlier research workers.