Why is a “ring of life” more appropriate to describe the relationships between archaea, bacteria, and eukaryotes than a “tree of life?

 “Tree of life” is a traditional model that describes the origin of Eukaryotes and the relationships between organisms. According to this model, Eukaryotes and Archaea are sister lineages, both descended from bacterial ancestors.  

Explanation:

On the other side, “ring of life” is a modern model by which Eukaryotes arose from a fusion of the other two domains (Archea and Eubacteria) of life. Ancestors of Archea and Eubacteria fused their genomes to form the first Eukaryote-two different branches of the “tree of life” were fused to form the “ring of life”.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.