1 The first endiosymbiosis ended in a great diversification of
2 a lineage comprising \textit{Red Algae, Green Algae} and \textit{Land Plants} (terrestrial).
3 Several Second Enbiosymbioses occurred then: two involving a Red
4 Algae and other heterotrophic eucaryotes and giving birth to both Brown
5 Algae and Dinoflagellates lineages; another involving a Green Algae and
6 a heterotrophic eucaryot and giving birth to Euglens\cite{mcfadden2001primary}.\\
7 The interesting point with the tree produced (especially from DOGMA) is
8 that organisms resulting from the first endosymbiosis are distributed in
9 every of the lineage found in the chloroplast genome structure
10 evolution: with Red Algae chloroplasts together in one lineage, and
11 Green Algae and Land Plants chloroplasts together in another lineage;
12 while organisms resulting from secondary endosymbioses are more localized in
13 the tree: both the chloroplasts of Brown Algae and Dinoflagellates
14 representatives are found exclusively in the lineage also comprising the
15 Red Algae chloroplasts from which they evolved, while the Euglens
16 chloroplasts are related to the Green Algae chloroplasts from which they
17 evolved. This makes sense in terms of biology, history of lineages, and
18 theories of chloroplasts (and so photosynthetic ability) origins in
19 different Eucaryotic lineages\cite{mcfadden2001primary}.
20 Interestingly, The sole organisms included that possesses a
21 chloroplast (and so a chloroplastic genome) but that have lost the
22 photosynthetic ability (being parasitic plants) are found at the base of
23 the tree, and not together with their phylogenetically related species. This means that functional chloroplast genes are evolutionnary constrained
24 when used in photosynthetic process, but loose rapidly their efficiency
25 when not used, as recently observed for a species of Angiosperms\cite{li2013complete}. These species are \textit{Cuscuta-grovonii} an Angiosperm (flowering plant)
26 at the base of the DOGMA Angiosperm-Conifers branch, and
27 \textit{Epipactis-virginiana} also an Angiosperm at the complete base of the tree.
28 Another interesting result is that land plants that
29 represent a single sublineage originating from the large and diverse
30 lineage of green algae in Eucaryots history are present in two different
31 branches of the DOGMA tree, associated with Green Algae, one branch
32 comprising the basal grade of land plants (mosses and ferns) and the second
33 comprising the most internal lineages of land plants (Conifers and flowering plants).
34 But independently of their split in two distinct branches of the DOGMA
35 tree, the Land Plants always show a higher number of functional genes in
36 their chloroplasts than the green algae from which they emerged, probably meaning that the
37 terrestrial way of life necessitates more functional genes for an
38 optimal photosynthesis than the marine way of life. However, a more detailed
39 analysis of selected genes is necessary to better understand the reasons why?
