1 Identifying core genes is important to understand evolutionary and
2 functional phylogenies. Therefore, in this work we present methods to
3 build a genes content evolutionary tree. More precisely, we focus on
4 the following questions considering a collection of 99~chloroplasts
5 annotated from NCBI \cite{Sayers01012011} and Dogma \cite{RDogma}: how
6 can we identify the best core genome and what is the evolutionary
7 scenario of these chloroplasts.
