@Doubting Thomas: Whoah, there! Let's ignore that you seem to be implying evolution is directed towards a goal or ideal, because I know you know better than that. Still, biological immortality does seem to exist, and if anything seems to be found in primitive organisms. From Wikipedi, "Biological immortality":
Immortality may not be desirable for multicellular organisms, as the main controls over cancer are the apoptopic mechanisms...
Nonetheless,
Hydras are a genus of simple, freshwater animals possessing radial symmetry and no post-mitoticcells. The fact that all cells continually divide allows defects and toxins to be diluted. It has been suggested that hydras do not undergo senescence, and, as such, are biologically immortal.[6] However, this does not explain how hydras are consequently able to maintain telomere lengths...
Turritopsis nutricula is a small (5 millimeters (0.20 in)) species of jellyfish that usestransdifferentiation to replenish cells after sexual reproduction. This cycle can repeat indefinitely, potentially rendering it biologically immortal...
Older lobsters are more fertile than younger lobsters. Some scientists have claimed that they could effectively live indefinitely, barring injury, disease, or capture...
Planarian flatworms (both sexual and asexual) appear to exhibit an ability to live indefinitely and have an "apparently limitless [telomere] regenerative capacity fueled by a population of highly proliferative adult stem cells"
Obviously none of these organisms can survive all trauma, although the article also discusses tardigrades, which can survive extreme heat, cold, and IIRC even exposure to vacuum. However, the absence of apparent senescence in these organisms indicates some organisms- even animals- can potentially live forever.
