<P> In prokaryotes, natural bacterial transformation involves the transfer of DNA from one bacterium to another and integration of the donor DNA into the recipient chromosome by recombination . Natural bacterial transformation is considered to be a primitive sexual process and occurs in both bacteria and archaea, although it has been studied mainly in bacteria . Transformation is clearly a bacterial adaptation and not an accidental occurrence, because it depends on numerous gene products that specifically interact with each other to enter a state of natural competence to perform this complex process . Transformation is a common mode of DNA transfer among prokaryotes . </P> <P> The ancestry of living organisms has traditionally been reconstructed from morphology, but is increasingly supplemented with phylogenetics--the reconstruction of phylogenies by the comparison of genetic (DNA) sequence . </P> <P> Sequence comparisons suggest recent horizontal transfer of many genes among diverse species including across the boundaries of phylogenetic "domains". Thus determining the phylogenetic history of a species cannot be done conclusively by determining evolutionary trees for single genes . </P> <P> Biologist Peter Gogarten suggests "the original metaphor of a tree no longer fits the data from recent genome research", therefore "biologists (should) use the metaphor of a mosaic to describe the different histories combined in individual genomes and use (the) metaphor of a net to visualize the rich exchange and cooperative effects of HGT among microbes ." </P>

Living organisms include bacteria fungi plants and animals