Reflexions from the hypothesis of the last common ancestor. Disclosure 20
Proliferation of live beings has took the attention of the scientists, stimulating them to order them and study their origin.
The works of John Ray (Historia plantarum generalis 1686-1704) and Joseph Pitton (Institutiones rei herbariae 1700) are the firsts attempts to use a scientific methodology to order the existing live beings.
Years later. (1753) Carl Nilsson Linæus Publisher the text "Species plantarum" that is considered as the current taxonomy nomenclature.
However, all these taxonomists, have a common characteristics, they all stand up for the immutability of the species, because this characteristic is for them what give sense to the definition as specie. Based on this lines they achieve to classify around 15.000 species of animals and vegetals.
Thought the later discover of microscopic beings and genetic material questioned this situation for both, the live beings classification and for immutability of species.
Carl Woese and George Fox are the creators of the new taxonomy (Phylogenetic structure of prokaryotes: the primitive kingdoms 1977) base don the comparison of the RNA ribosomal of the 16s and 18s subfractions between different live beings species. According to their work, the genetic structure has hardly varied from the firsts ways of life in earth.
The results of these works allowed to create a new domain called Archea Duch as the scheme of the first tree of the life evolution. This scheme allows to think on the existence of a universal common antecesor that evoluted to the three domains Bacteria, Eukaryota and Archaea from whose evolutive separation did not exist an horizontal genetic transference (transmission of the genetic material from individuals of one specie to individuals of another domain).
However, the Works of Klenk during genoma sequentiation of Archaeoglobus fulgidus (one of the two Archeas species) in 1997, detected an anomaly because the codifying gen of HMGCoA reductase was of bacterian origin.
Because of this, the hypothesis of an specific micro-organism that evolved in the three kind of molecules (bacteria, archeae and eukaryote) seem to be currently improbable. However the idea of a community of cells existing 3.500 million years ago, that exchanged genetic material (horizontal transfer)and became the three domains that share common genetic capabilities.
These reflexions about the hypothetic primitive cells exchanging genetic material lead us to questions like:
1.-How this genetic material was integrated in the cellular walls?
2. A genetic exchange occurred o the genetic material was previously existing and this is the reason that the three kind of cellules share genetic capabilities?
3. The evolution of primitive cells was by addition of genetic material, by modification of the already existing by effect of radiation or was there a code that allowed the genetic material to be unfelt until it became the genoma of the current species?
4. If we wonder about the future evolution, the current deployment is the final position or is there in current species, “latent” material that would be unfold , in a programmed way, from the primitive cells instructions to give new species?